Documenting and preserving Virginia’s largest, most revered trees

May 23, 2024 · 14 minute read
Documenting and preserving Virginia’s largest, most revered trees

Virginia is home to nearly 80 national champion big trees, consistently placing the commonwealth in the top five states with the most documented champion trees, or trees that have grown to be the largest specimens of their particular species.

The Virginia Big Tree Program, coordinated by the Department of Forest Resources and Environmental Conservation at Virginia Tech, maintains a register of the largest specimens of over 300 native, non-native and naturalized tree species in Virginia.

The trees are ranked based on a scoring system that takes into account their trunk circumference, overall height and average crown spread. Anyone can measure, or hunt, big trees and submit their findings for nomination by the Virginia Big Tree Program.

Trees that are national contenders can be nominated by the National Champion Tree Program, coordinated by the University of Tennessee Knoxville’s School of Natural Resources.

“A lot of people oftentimes think that in order to find a giant champion tree that you’d have to be out in the wilderness somewhere, but that’s not the case,” said Eric Wiseman, associate professor of urban forestry at Virginia Tech and program coordinator for the Virginia Big Tree Program.

“Really you just need a place where the growing conditions are suitable and the tree’s left alone for long enough that it can grow to extraordinary size,” Wiseman said.

The high number of national champion trees found in Virginia is due in part to its extensive forest lands. “About two-thirds of our state has forest cover,” said Wiseman. That includes an abundance of urban forests.

Every single tree in an urban area, whether found in a park, on a street or in someone’s yard, makes up the urban forest, said Molly O’Liddy, the Virginia Department of Forestry’s urban and community forestry partnership coordinator.

“A very healthy representation of our champion trees are in urban areas,” said Wiseman, and having large trees in cities is “really important for the environmental quality.”

Not only champion trees but every big, mature tree provides “so many benefits that young trees take decades to achieve,” O’Liddy said.


Cooling urban areas 


One of the biggest benefits of large trees is cooling our urban centers, said Ann Jurczyk, the Chesapeake Bay Foundation’s Virginia urban restoration manager.

Large trees generally have extensive canopies that provide shade over urban streets, sidewalks and parking lots that would otherwise be much hotter, posing significant health risks during summer months through what is known as the urban heat island effect.

study by Jeremy Hoffman, director of Climate Justice and Impact at Groundwork USA, found that Richmond’s neighborhoods most vulnerable to high temperatures overlap with historical maps of redlining, a discriminatory practice that took place in the wake of the Great Depression that denied home financing and housing services to communities based on their race or ethnicity.

The data suggest that communities that were redlined in the 1930s, including majority-Black and Hispanic neighborhoods, have fewer trees and more pavement, resulting in temperatures that can be several degrees hotter during the summer.

Extreme heat is known to be the number one weather related killer in the United States.

The cooling effect of trees not only protects communities from extreme temperatures but also encourages people to get outside and exercise in their neighborhoods more than they would with no shade and “blazing hot” temperatures, said Jurczyk.


Cleaning air and water


Runoff and stormwater management is “really a concern for a lot of Virginia communities,” especially those located within the Chesapeake Bay watershed, said O’Liddy.

The extensive canopies and root systems of big trees means “they play a really important role in our water cycle, so having clean water but also provision of abundant water is a really important role of forests in general but large trees specifically,” said Wiseman.

“From a water quality perspective, these trees do a great job of capturing rainfall and then slowly letting it evaporate from their leaves or needles,” said Jurczyk. This reduces the amount of stormwater runoff entering the Chesapeake Bay and the amount of harmful sediment and pollutants it carries with it.

Trees also capture pollution in the air, helping to “clear the air of ozone, carbon dioxide and other particulates,” Jurczyk said.

As trees grow larger, they accumulate significant amounts of carbon storage. “That is a really important ecosystem service of forests for humanity because it pulls carbon out of the atmosphere,” said Wiseman. “And we know that carbon dioxide is a contributor to global warming and climate change.”

The Biden administration set a goal of achieving a carbon pollution-free power sector by 2035 and a net zero emissions economy by no later than 2050, and trees are expected to play a crucial role.

On top of their carbon storage benefits, big trees can also lower energy usage in homes and buildings by providing shade during the summer months and protection from cold winter winds during the winter.

“We can absolutely point to trees having the potential to greatly reduce utility bills,” said Jurczyk, which is “one of the selling points” for homeowners and developers who are deciding whether or not to keep trees on their properties.

“I’m never quite sure which of the benefits gets the most traction with the public,” but the list goes on and on, said Jurczyk.


Providing habitat for wildlife


“In natural ecosystems, another important role of large trees is wildlife habitat,” said Wiseman. “As they grow very large and attain great height, we can see what’s known as niche stratification, or different microhabitats in the vertical structure of the forest.”

The vertical structure of mature forests contains what is called an understory, midstory and overstory. “Species of all sorts of wildlife occupy those various specialized niches, and very large trees help with that,” said Wiseman.

As trees grow older, they can develop defects such as cavities and large internal openings, which “become really important habitats for roosting, hibernating or nesting for an assortment of wildlife.”

“I wish everybody had the same love and certain knowledge about how all of these things are connected,” said Jurczyk, who referred to trees as “free infrastructure.”

“Hopefully by building the awareness for how special a single individual tree can be in terms of the benefits it provides to the environment,” Jurczyk said, more people will look at that tree in their backyard and go, ‘you know, maybe I’ll keep you.’”


Cultural and historical values


“For a large specimen tree, there’s kind of an element of intrinsic appreciation and value,” said Wiseman. “But also, oftentimes these trees have a historical connection with a place, a community or an event.”

Virginia’s oak species are particularly revered due to their tremendous value in timber and wood products, their ecological benefits and their cultural and historical significance, said Wiseman.

Oaks are among Virginia’s longest lived tree species, and they can be upwards of 300 to 500 years old.

“A lot of these trees were around right at the birth of our country, let alone our state, so just having something that you walk by everyday that has seen so much is pretty magical,” said O’Liddy.

One such tree, the Emancipation Oak on the campus of Hampton University, is where members of the Hampton community including formerly enslaved people and freedmen gathered in January 1863 to listen to one of the first official public readings of President Abraham Lincoln’s Emancipation Proclamation in the South. Pioneering African American educator Mary Smith Kelsey Peake taught Black men, women and children to read and write beneath the oak’s sprawling branches during the Civil War.

 The Algernourne oak is a roughly 500 year-old live oak that was named for the original fort built by Captain John Smith and the Virginia Company in 1609 on what is now Fort Monroe in Hampton, Va.. (Courtesy of Carol King and the Virginia Big Tree Program) 

Nearby, an even older tree in Fort Monroe called the Algernourne Oak is estimated to be approximately 500 years old. It has witnessed the days of Indigenous life before colonists arrived as well as numerous important moments in American history, including the landing of the first ship to carry enslaved Africans to the English colonies in North America in present day Hampton.

“The amazing thing about both of those trees is that they are publicly accessible,” said O’Liddy. “For folks to actually stand next to a specimen that is hundreds of years old and to think about the history, especially in that area, of what that tree has witnessed is pretty powerful.”

Another especially revered tree, the national champion osage-orange tree, is located beside the site of Patrick Henry’s former home in Charlotte County, Virginia. Osage-orange trees are “not super common on the landscape, so seeing a very large mature one is something that is really special, and it’s pretty awesome that the national champion is on the property of someone so historically significant,” said O’Liddy.

 Located on the grounds of the Patrick Henry National Memorial, this national champion osage-orange tree is one of the most revered in the Virginia Big Tree Program register. (Courtesy of Alex Cassell and the Virginia Big Tree Program) 


Big does not always mean old


Perhaps surprisingly to some, “Size is never ever a good predictor of age,” said Carolyn Copenheaver, professor in the Department of Forest Resources and Environmental Conservation at Virginia Tech who studies forest ecology and dendrochronology, or the study of annual growth rings in trees.

Recently, Copenheaver was coring trees to study their age in a small forest on Virginia Tech’s campus. A pignut hickory that Copenheaver assumed was a sapling due to its small four inch diameter turned out to be 164 years old.

“To find out that something that small is 164 years old, to me that’s what makes a tree charismatic, when it surprises you,” said Copenheaver. “If you’re in a forest that’s been forested for a long, long time, those small trees in an understory can be incredibly old.”

Likewise, if you see a big tree in an open field, “people will assume it’s been there forever, and it usually hasn’t,” said Copenheaver. Its growth rate is just much faster because it isn’t competing with other trees around it.

When talking about trees, “old” is a completely relative term. In an ecosystem where you have frequent fire, an old tree may be just 50 years old, said Copenheaver.

“Whereas if we’re talking about a tree here in the mountains of Virginia, you better be at least 150 to 200 years old before you’re really considered old.”

The oldest trees in Virginia that Copenheaver has cored are usually on inaccessible sites, or places that are “pretty uncomfortable for humans to get to,” said Copenheaver, who has rock climbing friends who repel down steep terrain to find trees that are “incredibly old” growing off the sides of cliffs.

“If you want to be really, really old,” said Copenheaver, you have to have survived not only the clearing of land by colonists but also Indigenous tribes, who also cut down trees for agriculture and timber.

The oldest trees Copenheaver tends to regularly see are white oaks due in part to their ability to compartmentalize decay, allowing the rest of the tree to keep growing without being impacted by that injury.

Virginia’s longest lived species of tree is the bald cypress, which has been documented to live well over 1,000 years old.


Threats to big trees 


Threats to big trees are varied, and they are more or less significant depending on where you are, said Wiseman.

Big trees in urban and urbanizing areas face threats associated with land development.

When land parcels are subdivided and lots made smaller, “it is exceedingly difficult to retain large trees” due to the simple fact that there is not enough space to install a building foundation and underground utilities while still retaining sufficient room for the root structure of big trees, Wiseman said.

Virginia’s champion trees that are found in remote rural areas are, on the other hand, “more or less safe guarded from direct assaults from human beings,” said Wiseman. But they are still susceptible to pests, disease, invasive plants, extreme weather events and climate change.

The American elm was “probably the most widely planted tree in American cities” at one time during the 19th and 20th centuries, said Wiseman, “but we lost nearly all of those trees when Dutch elm disease was accidentally brought into the US in the 1930s.”

“Having a survivor elm, as you might call it, and it being the national champion is special for us,” Wiseman said.

The predicted consequences of climate change, “especially related to escalating temperatures and changes in rainfall,” are also going to impact the composition and regeneration of certain vegetation communities, Wiseman said.

“Climate change is certainly something that raises concern at the ecosystem level for a lot of our forests,” said Wiseman.

To what extent that’s going to imperil individual specimens of living trees, said Wiseman, “it’s difficult to speculate about that.”

Some of Virginia’s high elevation species, particularly the firs and spruces that are endemic to the highlands of Virginia, “are imperiled by climate change because there’s only so high they can go up the mountain ridge to stay within a suitable climate range,” Wiseman said.

Whether it’s sooner or later, said Wiseman, “the time may come when we no longer have the size of native spruces and firs that historically occupied our landscapes.”

Changes in the amount of overall tree canopy are being tracked throughout the entire Chesapeake Bay watershed by the Chesapeake Bay Program land use and land cover data project.

Updated data is expected to be released this year from high resolution satellite imagery that will show how land cover and land use has changed between 2018 through 2022.

Jurczyk said experts anticipate that the tree canopy loss between 2018 to 2022 is exponentially more than it was during the 2013 to 2018 timeframe of the first data analysis.

“But here’s what we don’t know: is that being lost to utility scale solar? Is it being lost to right of way for utilities? Is it being lost to road construction for the widening of I-64, 81, and 95?” said Jurczyk.

Land use and land cover change data will help to “inform policy in the future so that we can make wiser decisions about how we protect canopy and how we plant it,” Jurczyk said.


Legislation to protect individual trees 


The Virginia Big Tree Program is celebratory not regulatory, meaning that “having a tree registered does not in and of itself impart any special protection for the tree,” said Wiseman.

On one hand, the lack of protection is viewed as a good thing by some landowners.

“Understandably, people who own a champion tree have a little bit of hesitancy about nominating the tree and having this recognition because they feel like it may encumber their private property rights or require them to protect the tree in a way that might be burdensome for them,” said Wiseman.

On the other hand, with a few exceptions, homeowners can legally decide to cut down any tree on their property, including those specimens that have enormous environmental, cultural and historical significance.

 This American elm in Chesapeake stands over 100 feet tall and was declared national co-champion in 2020 with a tree in Maryland. (Courtesy of Eric Wiseman and the Virginia Big Tree Program) 

Trees that are protected by law are those found within designated preservation areas. That includes any tree within 100 feet of a stream or river in localities within the Chesapeake Bay Preservation Act Area, which encompasses over 80 localities in eastern Virginia’s tidewater region.

Certain trees are also legally protected in some localities that have adopted individual specimen or heritage tree ordinances.

The Virginia General Assembly passed enabling legislation that allows localities to adopt a tree conservation ordinance to regulate the preservation and removal of heritage, specimen, memorial and street trees.

Only a handful of localities have chosen to adopt the ordinance; some of them can be found on Virginia Tech’s tree ordinance database.

Localities that choose to adopt the ordinance can decide how they would like to enforce or incentivise landowners to preserve trees that are designated for protection. The code allows for civil penalties of up to $2,500 for each violation.

In many cases, landowners must voluntarily nominate their trees for designation before any civil penalties for cutting down a tree would apply.

In other cases, such as in the City of Williamsburg, civil penalties have been removed from the ordinance language altogether. Instead of being regulatory or punitive, Williamsburg’s heritage tree program is intended to “heighten public consciousness by informing and educating the public of the benefits that not only Heritage Trees, but trees in general, provide to the community.”

 The state champion Compton oak is famously located in Market Square within the boundary of historic Colonial Williamsburg. (Evan Visconti for the Virginia Mercury) 

Williamsburg incentivises landowners to nominate trees to its heritage tree program by providing a plaque for the tree, posting a photo of the tree on the city website and offering to consult with landowners about proper pruning techniques and alternatives to removing or damaging a designated tree.

“These ordinances go hand in hand with public education about the benefits of trees,” said Kenny Fletcher, Chesapeake Bay Foundation director of communications and media relations.

“Not every locality is going to adopt an ordinance, which means there are plenty of people in Virginia who it’s up to them whether or not they’re going to preserve trees.”

Help stop the invasive spotted lanternfly

May 23, 2024 · 2 minute read
Help stop the invasive spotted lanternfly

It’s visually striking.

When fully grown, open wings display showy hind wings with bright red near the abdomen, black spots, and black-and-white bars.

But the spotted lanternfly, an invasive insect that came to the United States from its native habitat of Southeast Asia in 2014, is destructive. Despite its name, though, the spotted lanternfly is not a fly. It belongs to the order Hemiptera, which includes true bugs, aphids, and cicadas.

These insects colonize quickly, disrupt native ecosystems, and potentially cause problems to agriculture and forest health. The spotted lanternfly is also a significant threat to Virginia’s grape and wine industries.

The College of Agriculture and Life Sciences at Virginia Tech, the Institute of Agriculture at the University of Tennessee, and the College of Agricultural and Environmental Sciences at the University of Georgia are working together to build public awareness about these most unwanted visitors through collaborative videos, social media posts, and stories.

In Virginia, the College of Agriculture and Life Sciences and the Virginia Department of Agriculture and Consumer Services are partnering to empower residents of the commonwealth to act themselves on the spotted lanternfly.

“We need to prevent spotted lanternfly from going somewhere else and becoming a bigger problem,” said Eric Day, manager of the Insect ID Lab in the Department of Entomology. “Make sure it does not move on vehicles or plants and remove and squish any you find.”

In late spring and early summer, look for the immature stages and control them early on grapes or in backyards. Also look in your backyard for the spotted lanternfly’s favorite host tree – the tree of heaven. If possible, remove those trees as they function as a host that enables the insect to spread further and quicker.

As the summer heat ramps up, check car wheel wells, boat trailers, or box trucks to make sure the unwanted hitchhikers haven’t found a free ride. Everyone can play a part by stomping the spotted lanternfly.


“I’ve been impressed with the citizens of Virginia in their efforts to reduce the impact of the spotted lanternfly,” Day said. “Active citizens and businesses in quarantine areas have helped slow spread significantly. Now, to stop this insect from becoming a bigger problem, we must take action to make sure this hitchhiking insect doesn’t get any free rides through our state.”

In addition to the actions that everyone can take, Virginia Cooperative Extension has an abundant library of digital and online publications and resources geared toward providing our communities with specialized information tailored to local environments and challenges, such as resources to help with the spotted lanternfly.

Immerse Yourself In A Forest For Better Health

May 16, 2024 · 8 minute read
Immerse Yourself In A Forest For Better Health

Most of us sense that taking a walk in a forest is good for us. We take a break from the rush of our daily lives. We enjoy the beauty and peace of being in a natural setting. Now, research is showing that visiting a forest has real, quantifiable health benefits, both mental and physical. Even five minutes around trees or in green spaces may improve health. Think of it as a prescription with no negative side effects that’s also free.

Health Benefits From Forests

The reference list at the bottom of this page has links to specific studies on these benefits.

Exposure to forests and trees:

  • boosts the immune system
  • lowers blood pressure
  • reduces stress
  • improves mood
  • increases ability to focus, even in children with ADHD
  • accelerates recovery from surgery or illness
  • increases energy level
  • improves sleep

Forests Make Us Healthier

Numerous studies in the U.S. and around the world are exploring the health benefits of spending time outside in nature, green spaces, and, specifically, forests. Recognizing those benefits, in 1982, the Japanese Ministry of Agriculture, Forestry and Fisheries even coined a term for it: shinrin-yoku. It means taking in the forest atmosphere or “forest bathing,” and the ministry encourages people to visit forests to relieve stress and improve health.

person hiking on a trail

Research is casting light on how spending time outdoors and in forests makes us healthier:

Exposure to forests boosts our immune system. While we breathe in the fresh air, we breathe in phytoncides, airborne chemicals that plants give off to protect themselves from insects. Phytoncides have antibacterial and antifungal qualities which help plants fight disease. When people breathe in these chemicals, our bodies respond by increasing the number and activity of a type of white blood cell called natural killer cells or NK. These cells kill tumor- and virus-infected cells in our bodies. In one study, increased NK activity from a 3-day, 2-night forest bathing trip lasted for more than 30 days. Japanese researchers are currently exploring whether exposure to forests can help prevent certain kinds of cancer.

Spending time around trees and looking at trees reduces stress, lowers blood pressure and improves mood. Numerous studies show that both exercising in forests and simply sitting looking at trees reduce blood pressure as well as the stress-related hormones cortisol and adrenaline. Looking at pictures of trees has a similar, but less dramatic, effect. Studies examining the same activities in urban, unplanted areas showed no reduction of stress-related effects. Using the Profile of Mood States test, researchers found that forest bathing trips significantly decreased the scores for anxiety, depression, anger, confusion and fatigue. And because stress inhibits the immune system, the stress-reduction benefits of forests are further magnified.

Green spaces in urban areas are just as important as rural forests. About 85% of the US population lives in suburban and urban areas and may not have access to traditional rural forests. That’s O.K. Gardens, parks and street trees make up what is called an urban and community forest. These pockets of greenspace are vitally important because they are the sources of our daily access to trees.

Spending time in nature helps you focus. Our lives are busier than ever with jobs, school, and family life. Trying to focus on many activities or even a single thing for long periods of time can mentally drain us, a phenomenon called Directed Attention Fatigue. Spending time in nature, looking at plants, water, birds and other aspects of nature gives the cognitive portion of our brain a break, allowing us to focus better and renew our ability to be patient.

In children, attention fatigue causes an inability to pay attention and control impulses. The part of the brain affected by attention fatigue (right prefrontal cortex) is also involved in Attention-Deficit/Hyperactivity Disorder (ADHD). Studies show that children who spend time in natural outdoor environments have a reduction in attention fatigue and children diagnosed with ADHD show a reduction in related symptoms. Researchers are investigating the use of natural outdoor environments to supplement current approaches to managing ADHD. Such an approach has the advantages of being widely accessible, inexpensive and free of side effects.

Patients recover from surgery faster and better when they have a “green” view. Hospital patients may be stressed from a variety of factors, including pain, fear, and disruption of normal routine. Research found that patients with “green” views had shorter postoperative stays, took fewer painkillers, and had slightly fewer postsurgical complications compared to those who had no view or a view of a cement wall.

What Happens If We Lose Trees

The invasion of the emerald ash borer, or EAB, (Agrilus planipennis) since 2002 has provided an unfortunate opportunity to look at the effect of tree-loss on human health. EAB is a non-native, wood-boring beetle that kills all species of ash (Fraxinus) trees within three years after infestation. In some communities, entire streets lined with ash were left barren after the beetle arrived in their neighborhood. A study looked at human deaths related to heart and lung disease in areas affected by EAB infestations. It found that across 15 states, EAB was associated with an additional 6,113 deaths related to lung disease and 15,080 heart-disease-related deaths.

More Research Is Needed

While the research in Japan is groundbreaking, we need more research on trees growing in the Northeastern US. We share some of the same genera with Japan, like pine, birch and oak, which all give off different phytoncides, but we have different species. The more we know about our local trees, the more applicable the science will be.


Scientific Research and References

Please note: the following links leave the DEC website.

Urban Forests


Additional Resources

Northern Virginia, as part of regional approach, adopts goal of maintaining 50% tree canopy

May 9, 2024 · 6 minute read
Northern Virginia, as part of regional approach, adopts goal of maintaining 50% tree canopy

A Beech tree. (Courtesy of U.S. Fish and Wildlife Service)

The Washington D.C. area has seen tree canopy decline from over 50% to just under that amount in less than a decade, according to the regional government authority.

Officials with the Metropolitan Washington Council of Governments, which includes Northern Virginia jurisdictions, voted last week to set a goal of maintaining at least that 50% amount.

“There’s a lot of things that are unpredictable,” said Michael Knapp, MWCOG regional tree canopy subcommittee chair and tree specialist with the Montgomery County Department of Permitting Services. “We feel that the 50% is attainable and realistic based on current conditions.”

The goal, which jurisdictional members may act on voluntarily, comes after the MWCOG in 2020 adopted its climate and energy action plan, which includes planning for urban tree canopy adoption to achieve the region’s climate and energy goals.

 A graph from the Metropolitan Washington Council of Government’s report on tree canopy showing trends if nothing or a couple options are taken. (Photo courtesy of MWCOG)The recent tree canopy goal is also the culmination of years of work to produce a report that found the region in 2014 had 51.3% of land covered by tree canopy. In 2023, that number decreased, spurred by  development and other reasons, to an estimated 49.6%, a trend that, if it continues, would result in about 44.4% of tree coverage by 2050.

“The idea is to use trees and forests as a means of improving the quality of life and environmental health in the region by optimizing the services and benefits they provide,” Knapp said in a phone interview. “In order to sustain the same level of environmental help, you would either have to put money into man-made technologies that provide those types of services and benefits, or experience a decline in environmental health and economic vitality”

Trees have been proven to contribute numerous benefits to the environment, from reducing stormwater pollution runoff and sediment erosion, to capturing carbon and mitigating heat islands.

The report used information from the Chesapeake Bay Program model years 2014 and 2018, which identifies tree canopy as a way to meet pollution reduction goals. More recent Bay Program data is being finalized for next year. MWCOG also used satellite imagery to determine the percentage of tree canopy within a locality.

 A chart from the Metropolitan Washington Council of Government’s report on tree canopy. (Courtesy of MWCOG)

In terms of acreage, the largest loss in Virginia happened in Loudoun County, with about 2,800 acres swallowed up primarily by home development, Knapp said. The region has also seen an increase in data center development, which Knapp said comes after the region had branded itself as a tech corridor and home to former internet provider powerhouse AOL.

But because of land being converted to housing, Loudoun County has an opportunity to make gains in canopy because of Virginia tree ordinances that require builders to replace trees lost during the home building process, Knapp said, as opposed to land being developed for commercial industry uses.

Arlington and Alexandria made gains on tree cover, adding 7.6 acres and 18.8 acres, respectively. Knapp said the increases are likely due to trees planted under those localities’ regulations coming to bear, Knapp said. Those levels are expected to remain stable given the amount of development that occurs on a yearly basis, he added.

The largest canopy increase was Frederick County, Maryland, with about 2,100 acres, which Knapp surmised benefited from a phenomenon known as “pioneer forests.”

Frederick County, similar to more rural Loudoun and Prince William counties in Virginia, has land that originally was set aside for agricultural purposes, but had been converted to developed land in recent years. If there were economic difficulties that delayed development, the land may have been untouched for years before being built on and trees sprouted during the wait, leading to the canopy now getting picked up by the satellite imagery.

This represents an opportunity to pick up some tree canopy as development occurs, similar to what happened in Northern Virginia, which was one of the top dairy producers in the state in the 1950s before it became developed into the bedroom community that it is, Knapp added. Fairfax County had tree conservation and stream valley preservation ordinances they could use.

“As those areas were developed, some of those pioneers were given the chance to develop and mature,” said Knapp.

The 104-page report from MWCOG outlines the costs offset by maintaining tree canopy and offers guidance for preserving trees that may be more susceptible to die from diseases or increased moisture from heavy rain.

“There’s just a lot of outreach and public education that local governments can do,” Knapp said. “They need to instill a sense of ownership in the community. Local governments cannot do this on their own.”

One counter argument to tree preservation requirements is the reduction of the number of houses that can be built on a lot, thereby reducing the housing stock size and increasing housing costs.

Andrew Clark, vice president of government relations with the Home Builders Association of Virginia, said in a previous interview: “Developers will find a way to make these ordinances work, but it may undercut localities’ objective to provide an array of housing. That’s just kind of a trade-off.”

But Knapp said a provision in Virginia statute allows for deviations to be made if allowed densities can’t be met, and stakeholders that worked on Virginia’s tree conservation law in 2007 had reached consensus by creating a cooperative process between the two perspectives. The trees, Knapp said, can be a marketing tool for prospective tenants who have come to desire them, which the home builders acknowledged.

“If you just planned for trees when you’re doing your development you won’t sacrifice your houses,” added Brian LeCouteur, MWCOG principal environmental planner and regional urban forester.

And whereas putting homes on farmland may cost less than cutting forestland, if developers plan to use forestland, which “just happens,” LeCouteur said, it can be less costly to preserve existing trees instead of needing to plant new pens.

“We’re not trying to pit agriculture against silviculture,” said LeCouteur. “The idea is to just put [trees] in the plan.”

Recently, Republican Gov. Glenn Youngkin vetoed bills that would’ve made Northern Virginia’s tree conservation process during homebuilding an option statewide. Another bill would’ve made some localities’ existing requirement to replace trees lost through homebuilding available to towns, cities and counties across the commonwealth.

“The fact that the bills made it out of the House of Delegates and the Senate to the governor’s desk is quite the achievement,” LeCouteur said. “I have a strong [sense they] will eventually make it to a governor’s desk in the coming years. People are definitely aware of these now, and realize how important trees are to our environment.”

The Potomac River Conservancy, which backed those bills this session, supports MWCOG’s tree-boosting goal, as does the Chesapeake Bay Foundation.

“Increased tree canopy goals and affordable housing don’t have to be mutually exclusive,” said Anna Mudd, senior director of policy at the Potomac River Conservancy, in a statement. “We look forward to continuing to work with all stakeholders to develop creative and equitable solutions that ensure that everyone in the Potomac River region has the opportunity to live in communities with clean air, clean water, and access to green spaces.”

Fires have consumed nearly 20,000 acres in Va. this spring. That could be good for the environment.

May 9, 2024 · 8 minute read
Fires have consumed nearly 20,000 acres in Va. this spring. That could be good for the environment.

A fire at The Waterfall Mountain complex west of Luray Wednesday night. (Photo courtesy of Peter Forister Photography)

It’s human behavior that gives state, federal agencies a reason for concern

Almost 20,000 acres have been lit by flames that primarily torched the western and central parts of the state so far during Virginia’s 2024 spring fire season. With about a week left until the season ends, that is double the amount of acres affected annually in the state across its 10-year average.

There’s no question that the fires visibly caused an immediate loss of vegetation and wildlife habitat, but state and federal officials said in interviews with the Mercury last week the blazes provide some benefits and are a centuries-old resource management tool.

“It does play an important role in the ecosystem,” said Michael Downey, assistant director for wildfire mitigation and prevention at the Virginia Department of Forestry. “In the public’s eye it is a natural disaster, but we do try to keep it in a controlled, contained environment.”

Prescribed, or controlled, blazes are regularly implemented by state and federal agencies, which include the Department of Forestry, the Department of Wildlife Resources and the U.S. Forest Service. It’s the unruly nature of the wildfires that can cause concern, particularly given the proximity to neighborhoods and communities where people live.

“We don’t want people thinking, ‘Let’s go start a wildfire,’ but there are benefits,” said Michael Puckett, a small game project leader at DWR, adding that the fires are not solely a matter of loss of wildlife habitat, but a “matter of change.”

It’s the human communities abutting the wooded areas that are inhibiting wildlife’s ability to roam freely to and from impacted areas. Humans also contribute to some of the causes of the fires.

“Awildfires grow in severity/intensity, we will see species moving in new patterns and places in order to find new habitat,” both immediately after fires and in the longer term as species’ ranges shift, said Misty Boos, U.S. conservation policy manager at Wildlands Network.

“This underscores the importance of protecting large, connected landscapes and wildlife corridors so species can move and adapt, but it also demonstrates the importance of wildlife coexistence.”

Flora and Fauna

Starting at the ground level, the fires’ effects can matriculate down into the soil, depending on the severity, determined by fire intensity and duration.

The fires’ effect can increase dirt’s water repellency, or inability to hold water, leading to it eroding and potentially ending up in waterways.

Following the fires that hit the state in 2016, researchers at Virginia Tech found that some severely-burned areas were water repellent at rates of 68-74%. The unburned areas showed water repellency at a rate of 0-18%, the research found.

“A lot of fires in [Virginia] don’t get as large or hot as those out west, but in local areas we can see pretty severe burn severities,” said Ryan D. Stewart, an associate professor at Virginia Tech.

“Areas that have moderate to severe burn severities can have issues like the upper duff and organic layers being consumed, and development of a layer a few inches deep that does not easily rewet.”

 A forest in Highland County during a prescribed burn by the Virginia Department of Forestry in 2021. (Sarah Vogelsong/Virginia Mercury)

On the flora aspect, the clearing of taller trees can pave way for sunlight to reach the lower level vegetation, said Puckett. Creating a more diverse portfolio of vegetation within the forest can create a more diverse ecosystem, added Lane Gibbons, fire management specialist at Shenandoah National Park.

“If you kind of think of it in terms of investing, you don’t invest all of your money in one thing. That’s too much of a gamble,” said Gibbons. “You really want a diverse portfolio. It works very [similarly] in forests. If you have more of a diverse portinfo — tall versus short, young versus old —  if you have a greater variation [and] then you have a greater variation of types of organisms using those resources.”

Over time, forests in Virginia have become more resilient, with thicker oak trees popping up in places more susceptible to fires, Gibbons added, with less-deterrent maple pines growing in areas less likely to catch a blaze.

While oaks may be stronger, they also can attract invasive animal species, like the Spongy Moth, whose presence requires some maintenance and can be found throughout the state.

The caterpillar-like creatures provide benefits to forested areas by thinning out trees, allowing other plants to grow. But the bugs feed primarily on the oaks attracting them, which, in addition to their fire resilience, provide numerous benefits to the climate, including capturing carbon in the atmosphere.

“We’re looking at ways to bring back oak and fire is one of those ways to do a timber stand improvement,” Downey said, describing the process of removing undesirable species and then setting fires to bring back nutrients into the soil. “That’s sometimes what oak needs for it to regenerate.”

On the fauna aspect, the Wildlife Center of Virginia took in a bear cub found to suffer from smoke inhalation. Smaller amphibious animals like the box turtle suffer from the havoc wreaked by the blazes, because they live in small brush or leaf litter and can’t move out fast enough.

But larger wildlife that call the western parts of the state home, like turkey or small game like squirrels, may be displaced immediately, but sometimes they can be seen returning to the area before the smoke clears, Puckett said.

“We have enough moisture in the system here,” said Puckett, adding that wildlife can return within a year. “It’s not like cases out west that may burn down into the soil with the dry climate and lack of rainfall. Things don’t tend to recover as quickly as they do here.”

Human influence

It’s often humans, who infringe on animal habitats, that create cause for concern related to wildfires.

According to information released in January by the Weldon Cooper Center for Population Estimates, some rural areas of Virginia saw losses in population while others saw gains. Page County’s population grew by 2 to 4% from 2020 to 2023. Some central and eastern areas of the state, including Louisa County, grew by over 4%.

 Population change from 2020 to 2023. (Courtesy of Weldon Cooper Center Population Estimates)

Those increasing populations spur the development of communities abutting wooded areas that frequently prevent wildlife from being able to roam freely away from fires. Republican Gov. Glenn Youngkin signed House Bill 309 and Senate Bill 461, which directs the Virginia Department of Forestry to create a plan that includes protection of wildlife corridors, and large contiguous blocks of forests.

“As we’ve seen, events like wildfire (as well as floods, hurricanes, extreme snow storms, etc.) can temporarily bring wildlife into closer proximity to people, which can cause conflicts,” said Boos, with Wildlands Network.

More development means more utility infrastructure, such as electric power lines, getting built. The strong winds this past season that led to  power lines being knocked down and sparking blazes, instead of natural causes like lightning strikes that happen in Alaska.

“80 to 90% of fires are caused by humans,” Downey said.

When asked about downed power lines causing some of the fires this past spring, spokesperson for Shenandoah Valley Electric Cooperative said the utility, “will continue to cooperate with all affected localities to assess damage as we rebuild damaged power grid infrastructure.”

“This widespread event, combined with extremely low humidity, made conditions favorable for wildfires,” said Preston Knight, SVEC spokesperson. “Many communities throughout our service territory have experienced wildfires and our hearts go out to those who have suffered anguish and loss.”

Residents can clear debris from around their homes to prevent the fires from spreading, a task the Department of Forestry can help with despite their limited capacity, Downey said.

“We can only do what we can with our resources,” Downey said.

Impact going forward

Leading up to the fall and spring fire season, there were periods of drought identified by the Department of Environmental Quality. A report from the U.S. The Department of Agriculture found that “increased fuel load and more frequent droughts may increase wildfire frequency and intensity within the Southeast.”

That same USDA report said ways to make forests more resilient included, “taking steps necessary to appropriately manage stand density, hydrologic characteristics, and natural habitats,” and that these steps “can also have a positive impact on the ecological functioning and overall health of the forest.”

Adding fuel to the fire, literally: A study out of the University of California Riverside found plants are more easily burning as a result of absorbing more carbon that’s in the air, carbon created by pollution.

Creating markets for pulpwood and biomass that come from the over 16 million acres of forests in Virginia, about 80% of which are privately owned, can help reduce fuels by removing “less desirable species and residuals from the understory and floor of the forest,” said Corey Connors, executive director of the Virginia Forestry Association.

One of the authors of the University of California study’s said in a statement that, “we do need to implement better fire control and have more prescribed burns to use up plant fuel. We need to get rid of the old stuff.

“But the best way to decrease wildfires is to mitigate our carbon dioxide emissions,” Gomez said. “We need more emission control now.”

In Virginia the largest sources of emissions are transportation, followed by the commercial industry sector and electricity generation, according to DEQ.

While international research points to human-created emissions causing climate change, the impacts of climate change on the fires affecting the adaptability of the ecosystem in forests is still being determined, Gibbons said.

“It’s a topic that we’re trying to figure out,” he said. “We’ll implement strategies as we learn more.”

State forestry program purges hundreds of Virginia Callery pear trees

May 1, 2024 · 3 minute read
State forestry program purges hundreds of Virginia Callery pear trees

Native trees given to residents from the Department of Forestry in exchange for chopping down a Callery pear tree. (Meghan McIntyre/Virginia Mercury)

The reckoning has begun for the smelly invader

Both residents and Virginia Department of Forestry officials agree: Callery pear trees, including the much-loathed Bradford pear variety, aren’t just offensive to the nose — they’re detrimental to the state’s environment.

A new state program is what led approximately 300 residents to the department’s headquarters in Charlottesville this past weekend, each having chopped down at least one pungent, invasive Callery pear in exchange for a native tree species.

Inspired by similar programs in other states like North Carolina, the department’s forest health program manager Lori Chamberlin said Virginia’s exchange aims to not only decrease the number of Callery pears across the state, but also inform residents about the importance of native trees.

“We have so many native tree species that could also provide spring flowers or shade that would just be better for our ecological environment,” Chamberlin said.

While the Callery pear might look aesthetically pleasing with its delicate white flowers, Chamberlin said that beauty comes with destruction. The tree’s dense leaf canopy can inhibit the growth of plants beneath it and its weak branches can break and damage property.

During a 2021 ice storm, department forester Laura Hudson said Callery pears were the trees most frequently damaged.

“What happens is when all that ice and snow sat on the tops of the trees, they just literally couldn’t handle the weight and started to break,” Hudson said.

Additionally, the tree alters soil by releasing a chemical that suppresses other plant species, its thorns can pop tires and it doesn’t attract caterpillars, which are an important food source for young birds.

Callery pears were first imported from Asia to the United States in the early 20th century for use in breeding programs to increase disease resistance in common pears. With its sturdy tolerance for environmental stressors, the tree became very popular for landscaping and street planting.

 A Callery pear tree that has been chopped down. (Janelle Catlett)

Many varieties have been developed over the years, although the “Bradford” pear tree is the best known. While the tree itself is sterile, Chamberlin said it can still be pollinated by other varieties of Callery pear trees.

“We have so many types of Callerys in our landscape now because people have, for a while, thought this was the perfect landscape tree and just kept planting it and planting it,” Chamberlin said.

Now that there are so many varieties, Chamberlin said the tree is able to cross pollinate and produce viable fruit, which birds  eat and spread its seeds to other areas. Currently, the tree can be found almost everywhere throughout the commonwealth.

Albemarle resident Janelle Catlett said her yard used to house several Callery pears before she and her husband chopped down all but one large tree. The program, she said, was a great excuse to finally get rid of it.

“Every year he says ‘I’m going to do it, I’m going to do it,’ but then he doesn’t do it,” Catlett said. “If we do this this year and take pictures of it we will get a new tree and so, bingo, we got it down.”

Chamberlin said she was blown away that registration for the event filled in two days, despite it being the department’s first time. Now, hundreds of native trees are being planted across the state.

“We definitely hope to expand in the future hopefully to other locations, not just Charlottesville, so this can be a true statewide program,” Chamberlin said.

Scientists discover forests that may resist climate change

May 1, 2024 · 3 minute read
Scientists discover forests that may resist climate change

Cold-air pooling is a phenomenon where cold air drops from mountaintops into valleys below. Credit: Melissa Pastore, U.S. Forest Service

While it’s common knowledge that mountaintops are colder than the valleys below, a new University of Vermont (UVM) study is flipping the script on what we know about forests and climate.

The study, published in Ecology and Evolution, explores forests that experience “ pooling,” a phenomenon where cold air at higher elevations drains down into lower-lying valleys, reversing the expected temperatures—warm at the bottom, cold at the top—that typically occurs in . That is, the  drops with descent from mountain to valley.

“With temperature inversions, we also see vegetation inversions,” says lead study author and former UVM postdoctoral researcher Melissa Pastore. “Instead of finding more cold-preferring species like spruce and fir at high elevations, we found them in lower elevations—just the opposite of what we expect.”

And the effect on these ecosystems is substantial: “This cold-air pooling is fundamentally structuring the ,” says study co-author and UVM professor Carol Adair.

This insight “can help forest managers prioritize and protect areas with frequent and strong cold-air pooling to preserve cold-loving species as the climate warms,” says Adair.

The researchers looked at three forested sites in New England, ranging from the shallow, crater-like Nulhegan Basin of Vermont’s Northeast Kingdom, to the higher peaks and deeper valleys of the Green Mountains, over two years. They collected data on the types of trees present across elevation transects and monitored temperature hourly.

The researchers found that, far from being the occasional nighttime, seasonal phenomenon it’s historically been thought to be, cold-air pooling happens frequently, year-round, well into daylight hours, Adair says. The phenomenon occurred at every site they studied, but was strongest at the site with the shallowest elevation change.

Refuge in a changing climate

Locations experiencing this phenomenon might prove essential to conservation efforts aimed at preserving cold-adapted species, even as the larger climate warms, Pastore notes. “These cold-air-pooling areas could be valuable targets for small areas that provide a refuge from climate change; they’re areas that might be buffered from, or even decoupled from, climate change, and they’re harboring cold-adapted species that we know are vulnerable.”

She adds that conserving such locations may provide enough time for species to adapt to climate change by either migrating, or by mixing genes with neighbors to assume traits needed for survival in a hotter world.

In this way, Pastore says, “These pockets of cold habitat can act as steppingstones for some species—can buy them that time.”

Conserving such locations may have practical applications, as well, says Adair, “including  and small-scale recreational opportunities,” adding that cold-loving coniferous tree communities tend to store more carbon than deciduous trees, and forest soils may also hold onto moisture longer—important during periods of extreme rain.

Cold-air pooling has been historically and anecdotally observed elsewhere, Adair says, but this study is the first to quantify it to this degree across many sites beneath the , and more research is planned to explore its temporal and geographic extent.

Cold-air pooling is not a panacea, Pastore warns. These forests are “still going to warm—I definitely don’t want to say these are complete safe havens, because  will happen there, too—but it might be slower, and maybe species that might otherwise disappear in a  will remain longer in these locations.”

The research is highly relevant in a changing climate, as ecologists seek to model what may happen to species that require cold conditions. “If you don’t have this process in your model,” Adair says, “you’re going to miss that there are these areas where cold-loving species can persist and are persisting.”

The work has been a hopeful change of pace, Adair says. “I’m excited about the fact that this is good news, in a way. These areas can help cold-adapted  persist.” She adds, “A lot of my research is telling people why bad things are happening, so this is nice. It’s not all good news, but it’s some good news. These places exist. We can use them. They’re important. They’re clearly structuring forests.”

More information: Melissa A. Pastore et al, Frequent and strong cold‐air pooling drives temperate forest composition, Ecology and Evolution (2024). DOI: 10.1002/ece3.11126

Journal information: Ecology and Evolution

Provided by University of Vermont


Virginia Tech study considers ways to increase accessibility for all wildlife enthusiasts

April 12, 2024 · 3 minute read
Virginia Tech study considers ways to increase accessibility for all wildlife enthusiasts
According to the Centers for Disease Control and Prevention, one in four Americans has a disability and that number is expected to rise with an aging population. Evidence further shows that people with disabilities are also historically underserved in wildlife-related recreation, including birding. Photo courtesy of Adobe Stock.

One in three birders experiences accessibility challenges to participation in birding, according to Virginia Tech researchers Emily Sinkular and Ashley Dayer.

“I like to think of our research as blending together two previously unconnected fields: disability studies and wildlife recreation,” said Sinkular, a Ph.D. student and lead author of the study published March 26 in the journal Human Dimensions of Wildlife. “There’s been quite a lot of research on disability and lots of research on birding, but very few researchers have combined these two topics together.”

The researchers used a nationwide survey of U.S. wildlife viewers to compare the challenges and needs for birders with and without disabilities. Along with co-authors Freya McGregor, research associate in the Department of Fish and Wildlife Conservation, and Morgan Karns ’23, they analyzed open-ended responses using models of disabilities, or different frames of reference, to better understand how to talk about and think about disability so it resonates with disabled people.

“We suggest agencies and organizations reflect on how to make their programs more accessible and train staff or volunteers to do so as well,” said Dayer, associate professor in the Department of Fish and Wildlife Conservation. “Acknowledging that the responsibility to support participation of disabled birders rests on society and institutions, not on disabled people themselves, is essential.”

According to the Centers for Disease Control and Prevention, one in four Americans has a disability and that number is expected to rise with an aging population. Evidence further shows that people with disabilities are also historically underserved in wildlife-related recreation, including birding.

While the researchers found that birders with disabilities experienced more constraints than their peers, including lack of accessible features, safety concerns, and crowds at birding sites, commonalities in their needs for support of their recreational activity were also shown. Birders with and without disabilities expressed interest in access to more high-quality birding locations and information about where and when to view wildlife. This suggests strategies to improve wildlife viewing opportunities can benefit both groups.

“This shows us that agencies or organizations making changes to better include birders with disabilities can actually benefit everyone,” said Sinkular, who is also a student in the Department of Fish and Wildlife Conservation.

Ultimately, studying and planning for including people with disabilities in recreation will support broader social inclusion for this large population. The benefits of birding are multifaceted, including to mental well-being, social connections, and ultimately conservation actions. This research helps to bring these benefits to people with disabilities.

Emily Sinkular, shown on a wildlife excursion to the Great Smoky National Park in Tennessee, wants to use her Ph.D. research to help make natural spaces more accessible to all, knowing the benefits she receives from being in nature and connecting to wildlife. Photo courtesy of Emily Sinkular.
Ashley Dayer, a leader in conservation social science, is actively engaged in bird conservation, serving on Road to Recovery of North America’s Birds leadership team and elective member of the American Ornithological Society. Photo by Kris Timney for Virginia Tech.

Dayer’s Human Dimensions Lab has partnered with the U.S. Fish and Wildlife Service Multistate Conservation Grant Program to increase research on wildlife viewers with disabilities and to support state fish and wildlife agencies in learning how to better support these populations. Her lab specializes in enhancing conservation success through applying social science to effectively engage people and works to ensure that all voices are represented in research and conservation.

Dayer, an affiliated faculty member of Fralin Life Sciences Institute’s Global Change Center, said she hopes the work broadcasts a message of both inclusion and hope.

“My message for neurodiverse or disabled people: you are not alone in experiencing a desire to access nature and also facing additional challenges to doing so,” Dayer said. “And your challenges are increasingly being seen and addressed.”


Seeing the forest for the trees: Tree diversity is directly correlated with productivity in eastern U.S. forests

April 12, 2024 · 4 minute read
Seeing the forest for the trees: Tree diversity is directly correlated with productivity in eastern U.S. forests

When scientists and policymakers make tough calls on which areas to prioritize for conservation, biodiversity is often their top consideration. Environments with more diversity support a greater number of species and provide more ecosystem services, making them the obvious choice.

There’s just one problem. There are several ways to measure diversity, and each reveals a slightly different, and sometimes conflicting, view of how life interacts in a forest or other ecosystem.

In a new study published in the Proceedings of the National Academy of Sciences, researchers analyzed 20-years’ worth of data, which shows that the simplest measure of diversity — namely, adding up all the species for a given area — is the best way to measure the productivity of a forest.

“There aren’t many studies that look at the differences between measurements of diversity,” said lead author Yunpeng Liu, a postdoctoral associate at the Florida Museum of Natural History. Those that have, Liu said, typically used data from small, geographically isolated forest plots.

Liu specializes in forest productivity, and when he learned the U.S. Forest Service maintains decades’ worth of tree data, he knew exactly what he wanted to do with it.

Liu and his colleagues compared how three measures of biodiversity are related to productivity, or the amount of growth, in forests across the eastern United States. They did so by analyzing nearly two million tree measurements from 23,145 forest plots. Data were collected between 2000 and 2020 from non-plantation forests, meaning the trees grew there naturally.

The team found that a greater number of tree species, called species richness, consistently resulted in a more productive forest. This isn’t all that surprising, given that the interaction between multiple species creates robust ecosystem services, such as carbon storage, wildlife habitat and resources like wood that can be harvested and regrown.

The researchers assumed that other measures of diversity would also show a strong, positive relationship with productivity. Instead, they found that the measure of relatedness (phylogenetic diversity) and of various structural and chemical differences (functional diversity) were both negatively correlated with productivity.

Phylogenetic diversity shows how closely related the species in a given environment are to each other. Healthy environments typically contain multiple species that have only a distant relationship with each other, which allows them to collectively withstand change. If a virus or fungus were to sweep through and wipe out birch trees, the overall health of the forest would benefit from having various oaks, ashes, pines, walnuts and sycamores that remained unaffected.

Similarly, functional diversity is a measure of how much variety exists in the sizes, shapes and biological processes of organisms. The more differences there are in features such as tree size, wood density and rooting depth indicates how well a forest creates and makes use of all possible resources.

“These aren’t mutually exclusive measurements,” said co-author Douglas Soltis, a distinguished professor with the Florida Museum of Natural History. “They’re all ways that we might be able to make better conservation decisions.”

Forests with higher phylogenetic and functional diversity are more resilient, but whether they’re more productive is unclear.

“We aren’t yet sure,” said co-author Robert Guralnick, curator of biodiversity informatics at the Florida Museum of Natural History.

It’s possible there isn’t enough information about traits to make an accurate assessment. This is particularly true of the shape and depth of roots, which are difficult to measure.

“It may also be that there are aspects of how trees of the same or different species structure their interactions with each other, especially as tree communities become more diverse, that we don’t yet understand,” Guralnick said.

A better understanding of diversity is indispensable for the proper management of forests and has far-reaching implications. It’s estimated that plant productivity has balanced out up to 30% of carbon emissions caused by human activity over the last several decades. Forests play a significant role in this process but are also among the most threatened ecosystems on Earth.

For now, the number of species in a forest is the best proxy for its health and productivity. It also provides an easy guide for people working to restore degraded ecosystems, allowing them to focus their efforts on planting more species.

“It’s reassuring for other investigators and policymakers to know that species richness is reliable,” Soltis said, emphasizing the comparative speed and ease with which researchers can collect and analyze this type of data compared to other measures of diversity. “This is especially important when making conservation decisions with short notice and limited data.”

Funding was provided in part by the Postdoctoral International Exchange Program of the Office of China Postdoc Council and the USDA Forest Service (grant no. 21-JV-11242305-097).

Aaron Hogan and Jeremy Lichstein of the University of Florida, Pamela Soltis of the Florida Museum of Natural History and Samual Scheiner of the National Science Foundation are also authors on the study.

Sources: Yunpeng Liu,;
Douglas Soltis,;
Robert Guralnick,
Media contact: Jerald Pinson,, 352-294-0452

Enviva Forest Conservation Fund Helps Protect Virginia Forestland

April 5, 2024 · 1 minute read
Enviva Forest Conservation Fund Helps Protect Virginia Forestland

In a landmark conservation effort, 2,808.16 acres of Pierce’s Low Grounds in Greensville County, Virginia, have been permanently protected, securing a vital ecological asset for future generations. The property, recognized by the Virginia Department of Forestry with a high-ranking in “Forest Conservation Value,” is now protected from development, thanks to collaborative efforts and strategic partnerships.

The conservation initiative was made possible in part through a grant provided by the Enviva Forest Conservation Fund (EFCF), underscoring the commitment to preserving critical habitats and fostering biodiversity. This project exemplifies the power of partnerships in advancing conservation goals.

Key Features of Pierce’s Low Grounds:

  1. Ecological Significance: The Property, identified as part of the Virginia Piedmont Forest Block complex (Important Bird Area), boasts significant ecological importance. It houses diverse habitats crucial for the sustenance of various species.
  2. River Frontage: Pierce’s Low Grounds contains approximately 3,900 feet of frontage along the Meherrin River, a tributary of the Chowan River. This strategic location contributes to the protection of water quality in the Meherrin and Chowan Rivers, ultimately benefiting the Albemarle-Pamlico Sound Estuary.
  3. Threatened Species Habitat: Within the property’s boundaries lies habitat critical for threatened species, including Rafinesque’s Eastern Big Eared Bat, Eastern Mudsnake, and Green Floater. Preserving this habitat is a significant step in the conservation of these species.
  4. Natural Heritage Screening: The Property falls within the Claresville Bottomlands Natural Heritage Screening Conservation Site, further emphasizing its ecological significance and the need for its protection.

Estie Thomas, Easement Manager at Virginia Outdoors Foundation, expressed the importance of the preservation of Pierce’s Low Grounds: “This project nearly doubles the amount of pristine forest and habitat VOF has conserved in partnership with Enviva over the past decade. We are grateful for their support, and for the support of the landowners whose commitment to conservation is inspiring.”

Brandi Colander, Chief Sustainability Officer at Enviva, stated, “We are incredibly pleased to have been able to assist in the permanent conservation of this property due to its significant importance for critical bottomland forests as well as for the preservation and protection of precious habitats for various species, including threatened ones.”

The Pierce’s Low Grounds conservation project aligns with the broader mission of environmental stewardship and sustainable land management, ensuring the perpetual preservation of this significant natural landscape.

The Southern Pine Beetle: The Tree Killer 

April 5, 2024 · 6 minute read
The Southern Pine Beetle: The Tree Killer 
The geographic range of damage from the southern pine beetle.

Map/United States Department of Agriculture and the United States Forest Service

Given that it’s smaller than a grain of rice, it might be hard to believe that the minuscule southern pine beetle (Dendroctonus frontalis) could cause massive damage to forests! These beetles have been a well-known foe of the southern United States for centuries, but they are a new enemy to the Northeast.

The southern pine beetle was first recorded in the southeastern United States in the late 1700s. Though they are originally native to the southeast, warming winter temperatures have allowed the beetle’s range to expand up the east coast in recent decades.

Southern pine beetle from Pilgrim Heights, Truro under a microscope.
Photo/Felicia Hubacz, Massachusetts Bureau of Forest Fire Control and Forestry

When European settlers arrived in North America, they cut down many of the original forests that were primarily composed of trees like oak and hickory, which are naturally resistant to the southern pine beetle. With the soil quality altered from agricultural use by the settlers, pine species that are susceptible to the beetle grew back in the place of the oak and hickory. Infestations in New Jersey and New York started around a decade ago, and in 2023, there were outbreaks on Martha’s Vineyard and Nantucket. Early this year, an infested tree was identified at Pilgrim Heights in the town of Truro within the bounds of Cape Cod National Seashore.

Life cycle of the southern pine beetle.
Graphic/Ronald F. Billings, Texas A&M Forest Service

Unfortunately, it can be challenging to spot the beetles themselves, considering that they are smaller than half of a grain of rice in their adult form. The beetle looks different during each stage of its life:

  • The egg is white.
  • The larva is crescent-shaped with a dark red/brown head.
  • The pupa is white.
  • As an adult, they are light brown/black.
Popcorn-like pitch tubes on an affected tree.
Photo/Jiri Hulcr, University of Florida

Luckily, the physical appearance of the beetle isn’t the only way to identify their presence, as you can tell by the damage they cause. The presence of pitch tubes would be your first physical indicator. Pitch tubes look like popcorn sticking out of the bark; these are the tree’s natural defense against predators. If you peel back the bark of an infested tree, you might also find S-shaped designs drilled into the wood called “galleries.”

Southern pine beetle galleries drilled under the bark of the tree tend to look like complex mazes.
Photo/Jiri Hulcr, University of Florida

Female southern pine beetles will create these galleries to lay their eggs. The females also release pheromones to draw males to the trees. Once a tree becomes infested, it can die quickly. Often, the trees that the beetles choose are weakened ones, but that is not always the case. Southern pine beetles like to infest many trees in an area and have been known to kill acres of trees in very short periods of time. An outbreak can be very harmful for many reasons, but dangerous specifically for Cape Cod because of the Pitch Pine Barren habitat that many species rely on.

A southern pine beetle (left) and a black turpentine beetle (right) compared to a grain of rice (middle) in someone’s palm.
Photo/ Southern Forest Insect Work Conference Archives

Southern pine beetles are often mistaken for the black turpentine beetle, a familiar insect to the northeastern United States. Black turpentine beetles are larger than southern pine beetles, measuring up to the size of a grain of rice. Their damage to trees is visually similar, but there are a few key differences. The pitch tubes they create tend to be located from the foot of the tree to about fifteen feet up, whereas southern pine beetles tend not to cause damage around the tree’s base. Differences in the galleries made under the bark can also indicate which species is the culprit, with the galleries of black turpentine beetles tending to be less intricate. Black turpentine beetles also do not kill acres of trees at a time, but rather one to a few sickly trees in one area.

Lindegren funnel traps are an excellent way to monitor for the beetle, but must be checked regularly.
Photo/Mississippi Entomological Museum

Fortunately, we don’t need to wait for an outbreak to happen to confirm the presence of southern pine beetles. Setting and monitoring traps on trees or poles are effective ways of identifying a small population of beetles before things get out of control. Lindegren funnel traps are used to monitor for the southern pine beetle. These traps consist of a series of funnels that contain a preservative like ethanol at the bottom. The funnels are strung between two trees and attract the beetles, who mistake the trap for a tree.

Aerial view of an outbreak, where large patches of trees are dying.
Photo/Ronald F. Billings, Texas A&M Forest Service,

Aerial and ground surveys are another technique used to detect beetles in early and later stages. Sadly, many infestations of single or small groups of trees are caught too late, which leads to an outbreak, where larger swaths of forest are impacted.

Thinning of pine stands is a management technique used to combat the southern pine beetle throughout the United States. This sign indicating that the forest has been thinned to prevent southern pine beetles is located in Virginia.
Photo/ Katlin Dewitt, Virginia Department of Forestry

There are a few effective ways to treat a southern pine beetle outbreak. Prescribed burns, where planned fires are set and carefully managed, can combat an outbreak as well as strengthen the ecosystem in pitch pine forests.

Felling trees is another option, with a few different techniques available. The “cut and remove” technique consists of removing infected trees from the site to be processed, while “cut and leave” can be used when trees cannot be taken to a different location, so they are left where they are cut. Cutting down trees and thinning areas of forest creates more distance between trees, which makes it more difficult for the beetles to communicate via pheromones, find each other, and attack in large numbers.

The pitch pine habitat on Cape Cod will need to be protected from the destructive southern pine beetle to survive.
Photo/John N. Cullity, Sandwich Conservation Trust

The southern pine beetle will continue to be a threat to New England with the rise in average temperatures and warming weather. There are ways to combat and stop them from spreading further north, but people must be on the lookout for warning signs. Early detection is the best way to keep the beetles contained in a small area while determining a course of action for response and elimination. The southern pine beetle is a threat everyone should take seriously to protect Cape Cod’s Pitch Pine Barrens for generations to come.You can help keep our forests safe by following these guidelines:

  • Be on the lookout! If you see a tree displaying symptoms of southern pine beetle infestation, like pitch tubes, contact (508) 771-2144 or to report the tree.
  • Make sure you are not bringing in firewood to campsites and bonfires from elsewhere. Use local firewood instead!

Residents Urged to Report, Destroy Spotted Lanternfly Egg Masses

March 29, 2024 · 2 minute read
Residents Urged to Report, Destroy Spotted Lanternfly Egg Masses

Cleverly camouflaged as clumps of mud, spotted lanternfly egg masses easily go undetected. State organizations are asking residents to pay attention, and report and destroy egg masses before they hatch this spring. (photo by Virginia Farm Bureau)

The oval egg masses are about 1.5 inches long and a half-inch wide

CHARLOTTESVILLE, Va. — Cleverly camouflaged as clumps of mud, spotted lanternfly egg masses easily go undetected. State organizations are asking residents to pay attention, and report and destroy egg masses before they hatch this spring.

The Virginia Department of Forestry is hosting a Volunteer Spotted Lanternfly Egg Mass survey this March to monitor spread of the pest. Residents living outside of quarantine or known infestation areas who spot egg masses are encouraged to report them using the VDOF online survey form:

“Spotted lanternfly egg masses are laid in the fall but don’t hatch until the following spring,” explained Lori Chamberlin, VDOF forest health program manager. She said now is an ideal time to look for them, while trees are bare and branches are easily visible.

The oval egg masses are about 1.5 inches long and a half-inch wide. Shiny gray with a waxy protective covering, the masses eventually turn a dull grayish brown, strongly resembling patches of mud or lichen.

Spotted lanternflies lay eggs on the underside of branches, on tree trunks and on objects like vehicles, homes, lawn furniture, grills, dog houses and decorative yard items. They’ve also been found on fencing, tarps, decking, construction materials and firewood.

“Use binoculars—they can lay eggs in the very tops of trees,” Chamberlin said.

After reporting them, residents should destroy the egg masses by scraping them into a bag with rubbing alcohol or hand sanitizer.

“If that isn’t possible, smash them with a stick or hard object,” Chamberlin suggested.

The VDOF survey closes March 31, but residents living outside of infestation areas are encouraged to continue photographing and reporting egg masses and SLF sightings to DOF local area foresters or Virginia Cooperative Extension agents.

Subtle and tucked in hidden, protected areas, lanternfly eggs have proven pervasive and challenging to combat. To help the effort, a Virginia Tech program has been training dogs to sniff them out.

“Spotted lanternflies pose a significant threat to orchards and vineyards as well as homeowners’ lawns and gardens,” said Tony Banks, senior assistant director of agriculture, development and innovation for Virginia Farm Bureau Federation. “Everyone should be vigilant if they see new insects or egg masses on their property, vehicles or equipment.”

Spotted lanternflies feed on over 100 plant species but largely impact apples, hops, ornamental plants, stone fruits and wine grapes. The honeydew they secrete on plants causes sooty mold to grow—blocking photosynthesis in leaves, stressing the plant, and potentially leading to plant death.

Click here for more information on spotted lanternflies

Forestry and Wildlife Tours Connect VA Tech Campus to The Commonwealth

March 29, 2024 · 4 minute read
Forestry and Wildlife Tours Connect VA Tech Campus to The Commonwealth

For Jennifer Gagnon, the best part of leading Forestry and Wildlife Tours is the conversations that take place as she visits a forested property, tours a barrel cooperage, or drives a 12-passanger van to the next destination on the tour.

“The best part of these tours is the people sharing their stories,” said Gagnon, coordinator of the Virginia Forest Landowner Education Program. “The tours provide opportunities for people who own tracts of land to talk and learn from each other. They get the chance to make connections with other landowners and natural resource professionals.”

Connecting forest landowners with the research knowledge at Virginia Tech is a key aim of Virginia Cooperative Extension and the Virginia Forest Landowner Education Program.

“Private individuals and families own over two-thirds of all our forests in Virginia,” said Gagnon, a member of the College of Natural Resources and Environment’s Department of Forest Resources and Environmental Conservation. “We want the people who own those forests to have the information they need to take care of them, to make sure that they’re healthy and productive, so that we can all benefit from them, both environmentally and economically.”

Last fall’s forestry and wildlife tour series was the 47th iteration of the program, making it the longest-running Extension program of its kind in Virginia. Four tours were held in October, each with a schedule curated by district forestry Extension agents and reflected county-specific natural resource issues.

“The district foresters take the lead on planning our tours,” said Gagnon, who has coordinated the tours since 2006. “They put the hard work into reaching out to landowners or businesses and asking for permission to access land or tour a factory or a timber harvest. Then they’ll do a dry run of the route to check which sites can be accessed easily by a tour bus or van.”

This past year’s tours reflect the range of experiences and knowledge offered to participants. In Bland County, landowners visited a 500-acre Tree Farm, a family firewood business, and a timber harvesting operation before attending a presentation on the benefits of prescribed burning in the Appalachian forests. In Mecklenburg County, participants visited a Wildlife Management Area and then toured Virginia’s largest human-made lake to better understand the dynamics between human and ecosystem processes.

Access has always been a priority: The tours are planned to minimize strenuous walks, and scholarships are available for area K-12 teachers interested in learning about forestry and wildlife.

One way that Gagnon plans to make tours more accessible for 2024 involves the use of technology. “This year, we’re excited to introduce portable headsets for use on mill tours,” said Gagnon. “Typically, our participants are broken into groups with a leader, and it can sometimes be difficult to hear that’s being said inside a noisy facility. That should no longer be a problem.”

Gagnon said that the Fall Forestry and Wildlife Field Tours are a collaborative effort that rely significantly on the contributions of partners, including federal and state agencies, the forest industry, and private contractors.

“We couldn’t provide this service without the contributions of the Virginia Department of Forestry and the Virginia Department of Wildlife Resources, as well as other partners,” she said. “We’re tasked with providing educational programming to the entire state, and we really rely on the folks that work with landowners every day to keep us updated on what information and services we can provide.”

Jennifer Gagnon, coordinator of the Virginia Forest Landowner Education Program, has been participating in fall tours since 2006. Photo by Ray Meese for Virginia Tech.

In addition to the fall tours, Gagnon and two of the district forestry Extension agents lead winter Woods and Wildlife Conferences, where residents and landowners participate in presentations on subjects as varied as growing wild ginseng, managing invasive species, considering solar energy options, and discussing silvopasture strategies that allow livestock, trees, and vegetation to share a landscape. The group also leads Generation NEXT workshops on legacy planning for forest properties, workshops on best practices for prescribed burningonline courses and weekend retreats on forest management, and even a SHARP Logger program that details how to harvest trees safely.

For Gagnon – who boasts that she can now drive a 12-passanger van better than her own car – the highlight of the tours is having the chance to provide connections between forest landowners and the resources that drive Virginia’s third-largest industry.

“Our forest landowners spend 25 years of their lives growing a pine tree, or maybe 75 years growing a hardwood, and it’s always exciting to see them come into a place that is using that resource so they know that their work is contributing to the economics of the state.”

The 2024 schedule for upcoming Fall Forestry and Wildlife Field Tours will be available this summer. Sign up for a tour and read about all of the services and programs offered.

Volunteers join Nansemond Indian Tribe to preserve nature

March 26, 2024 · 2 minute read
Volunteers join Nansemond Indian Tribe to preserve nature

Suffolk Va. –Friday afternoon, Suffolk volunteers and the Nansemond Indian Tribe unite to heal the land from non-indigenous plant species.

In partnership with the Chesapeake Bay Foundation and the Virginia Department of Forestry, the tribe held their first Mattanock Town Tree Planting event on Friday, March 1, at 1001 Pembroke Ln. Part of a two-day series (also held Saturday, March 2), volunteers alongside both CBF and DOF officials worked with the tribe to plant various trees native to the area’s forest, such as black gum, witch hazel, hackberry, and more. Nansemond Indian Nation Chief Keith Anderson said it was an “amazing feeling” to see everyone come together to help restore the area’s forestry.

“We’re definitely blessed to have this, especially to do this along with community partners and citizens throughout Hampton Roads,” Anderson said.

CBF Restoration Coordinationor Kati Grigsby said it was a “major honor” to be invited to the planting and be part of the tribe’s journey of reconnecting their people with the local waterways. Grigsby talked about the results they hope to see from the planting.

“We’re hoping to have a canopy that actually will shade out the invasive species and then also root systems that will outcompete the invasive species root systems as well,” Grigsby said.

Grigsby also noted that rare sugar maple seedlings were found inside the footprint of the planting and that the Elizabeth River Project, Nansemond River Preservation Alliance and Virginia Tech Agricultural Research Extension Center are “babysitting” these seedlings until their planting later in the fall. CBF Virginia Executive Director Chris Moore also expressed how great the tribe’s work is in helping restore the area’s land.

“Even where we’re standing right now, you couldn’t walk through just a very short time ago because it was filled with invasive species. All these volunteers, all the folks from the tribe, all the partners are out here planting native species again, and so you’re going to see a huge difference in what this place looks like in a very short period of time,” Moore said.

Virginia Department of Forestry Urban and Community Delaney Long, who helped demonstrate the planting process for volunteers, says she felt “energized” seeing the turnout of volunteers helping with land restoration.

“So many people came out to help today,” Long said. “Seeing the site this morning when we got here to set up, it was hard to picture having a lot of people out here, putting trees in the ground, and maybe what this was going to turn into eventually, and now that everyone is here and excited and everyone’s got a tree in their hand, it is a little easier to just visualize the mature, healthy forest that this is going to be and what it can provide for this community.”

Finally, Anderson expressed his gratitude to everyone who came out for the tribe’s first planting.

“Just eternally grateful for the sincerity and support and just the desire that we’re doing this as a kinship,” Anderson said. “It’s not just about the tribe, but about building community relationships.”

Read more at:

Women in the Forest Service

March 26, 2024 · 1 minute read
Women in the Forest Service

Celebrating women

Women have been at the forefront of the Forest Service since its inception in 1905, serving in roles as advocates, foresters, rangers’ wives, clerks, information and education specialists, scientific researchers and lookouts. In these roles, they pioneered and supported the development of the agency’s forest management infrastructure, information base, conservation education, scientific research, and fixed-point fire detection system. Although women were not allowed in forestry schools or hired in professional or field positions during the first half of the 20th century, they found rewarding careers in the agency through alternative paths, studying environmental sciences or providing insight from the lens of daily administration.

After passage of the 1964 Civil Rights Act, women applied for professional and field positions and moved into jobs as foresters, firefighters and even district rangers and forest supervisors, leading to the first female Chief of the Forest Service in 2007. Women have had a profound impact on the Forest Service, working as a vital core from day one to help shape the agency’s information base and administrative infrastructure. Scroll down to learn more about women within the Forest Service through six biographical features, an interactive timeline, links to more information and photographs.

Women’s voices have long been part of the call for forest preservation and an ecological and moral approach to land management, but they have been overshadowed by those made by Henry D. Thoreau, George Perkins Marsh and Aldo Leopold. Beginning a century before Leopold published his essay, women were initiating calls for including ethical and cultural aspects of environmental management—two cornerstones of forest management today.

Click here to read more and watch a video from the US Forest Service.


Seven times size of Manhattan: the African tree-planting project making a difference

March 15, 2024 · 5 minute read
Seven times size of Manhattan: the African tree-planting project making a difference

Thousands of farmers have been persuaded by TREES scheme to replace barren monocultures with biodiverse forest gardens

In a world of monoculture cash crops, an innovative African project is persuading farmers to plant biodiverse forest gardens that feed the family, protect the soil and expand tree cover.

Could Trees for the Future (TREES) be a rare example of a mass reforestation campaign that actually works? The United Nations Environment Programme (UNEP) certainly thinks so and last month awarded it the status of World Restoration Flagship.

Since it was founded in 2015, the programme has planted tens of millions of trees each year in nine countries ranging from Senegal and Mali to Tanzania and Kenya. In less than 10 years, it has reportedly restored a combined area of more than 41,000 hectares, which is about seven times the size of Manhattan.

This includes part of the African Union’s Great Green Wall initiative, a planned 8,000km-wide barrier of vegetation to hold back the deserts that are encroaching across the Sahel region. Organisers say this will be the largest natural structure on the planet, though it is still very much a work in progress.

A smiling woman with vegetable plots behind.
A community nursery in Tanzania. Photograph:

Trees for the Future has ambitious plans to use reforestation to combat poverty. By 2030, it aims to create 230,000 jobs and plant a billion trees.

A commitment to restoration is essential, according to Inger Andersen, executive director of UNEP, who noted it was no longer enough to merely protect what was left of Africa’s fertile land. This continent will be home to a quarter of the world’s population in little more than a generation and many areas have already degraded into semi-barren drylands.

“Initiatives like TREES are playing an important role in reversing decades of ecosystem degradation, especially across the Sahel, pushing back desertification, increasing climate resilience and improving the wellbeing of farmers and their communities,” Andersen said in announcing the World Restoration Flagship.

While there is no doubt about the need for reforestation, there are historical reasons to be sceptical about the effectiveness of such programmes. Expectations are often too high. A 2019 study suggesting the climate crisis could be significantly eased by planting a trillion trees across the world was later debunked as unrealistic because there was not enough suitable land.

Many governments have launched mass tree-planting campaigns, but after the initial day or two of publicity, there is rarely sufficient irrigation, protection and other follow-up to ensure seeds and saplings grow into trunks and branches. Often such national initiatives are little more than greenwashing distractions from far greater forest destruction elsewhere.

Kenya, for example, has launched numerous tree-planting initiatives in recent decades, including the Million Operation Gavisha in 1977, the Trees Campaign in 2006, the Greening Kenya Initiative in 2010 and the Accelerated National Tree Growing Campaign 2022, yet overall, it has lost 11% of its tree cover since 2000.

The situation has stabilised somewhat in the past two years under the current president, William Ruto, who has declared an annual tree-planting holiday and set a national target to plant 15bn trees and raise tree cover to 30% by 2032. But the gains could be short-lived because Ruto recently lifted the six-year logging ban to boost economic growth. This puts more pressure on Mau forest, which is already being cleared for tea and wheat fields; Migori forest, which is encroached upon by sugar producers; and Nyanza forest, which is an expanding area for tobacco farmers.

The protection of primary forests is a priority for the global climate, local biodiversity and regional water cycles. Those functions, built up over centuries, cannot be fully replaced by new plantations and restoration projects. But TREES and similar programmes can help to alleviate ecological and economic problems in already degraded areas.

A woman looking up into a tree.
Trees for the Future 2030 aim to create 230,000 jobs and plant a billion trees by 2030. Photograph: Adobe PDF library 15.00/

At Kesouma, on the edge of Lake Victoria in western Kenya, organisers say they have supported 17,000 smallholder farmers with training, seeds, tools and grants to plant “forest gardens” instead of the monocultures that left their plots exposed and sucked dry of moisture, carbon and nutrients.

The area is subdivided into groups of 20 smallholders, represented by a lead farmer, who is paid a stipend of 3,000 Kenyan shillings every month. All members regularly meet for reporting, training and access to the tools and seed banks to nurture a forest garden. Individual plots, which cover 1 hectare on average, are said to have about 5,800 trees of multiple varieties.

On the outer perimeter there is a “protective wall” made up of three ranks of Acacia polyacantha (white thorn). Behind this is a cluster of tightly-spaced agroforestry trees that grow quickly and can be used for firewood and fodder. In the centre is a mix of vegetable gardens and orchards of mangoes, avocados, oranges, apples and other fruits. The aim is to provide sufficient nutrition to feed a family with a small surplus crop to sell at the market.

In one pilot area in the Lake Victoria basin, incomes are to be further bolstered by cash from carbon credits provided by the US firm Catona Climate based on gains in soil organic carbon, which is measured by experts from the University of Nairobi and Wangari Maathai Institute of Peace and Environmental Studies.

Monitoring is a key element in any reforestation programme, as is maintenance, particularly in remote areas. Major projects in China and Africa – including the Great Green Wall – have tried to address this by dropping seeds by plane in uninhabited areas. With species often unsuited to the terrain and irrigation impossible, this has often resulted in wasted efforts. In that regard, forest gardens seem more promising, though the scope is limited. Farmers usually live in or near their fields and have a financial incentive to ensure the quality of the soil and the healthy growth of a variety of trees.

Vincent Mainga, the Kenya director of TREES, said the project would expand rapidly now it has the endorsement of UNEP. “This is a massive restoration movement using regenerative agriculture,” he said. “This model is very easy to adopt. We work with the farmers for four years. After that, they can understand all the components and they can use what they learn from our technicians to produce thriving farmlands, usually with a surplus. It is self-sustaining.”

Stumpy’s last bloom: A beloved Tidal Basin cherry tree faces the ax

March 15, 2024 · 3 minute read
Stumpy’s last bloom: A beloved Tidal Basin cherry tree faces the ax

Stumpy, a beloved hollow cherry tree located on the south bank of the Tidal Basin in Washington, will be removed later this year alongside hundreds of other trees that will be cut down for a sea-wall-rebuilding effort led by the National Park Service.

The name was given to the stump-shaped cherry tree in 2020 by a Reddit user who joked that the tree was as dead as his love life. Since then, the tree’s popularity has only grown, and its resilience celebrated. The tree has survived years of flooding tides from the Potomac River and beavers browsing for bark.

“Stumpy is such a unique and well-loved tree because it’s small and deals with Tidal Basin flooding daily,” said Dave Lyons, a D.C.-area photographer. “Yet it’s full of beautiful cherry blossoms. Everyone cheers for the little guy.”

(Matt McClain/The Washington Post)
The National Cherry Blossom Festival in D.C. draws more than a million visitors from all over the world. Here’s our 2024 cherry blossom forecast for peak bloom.

Still, the tree’s days are numbered as a $113 million multiyear repair of Tidal Basin and West Potomac Park sea walls nears. About 300 trees overall, including more than 150 of the iconic cherry trees, will be removed.

Human-caused climate change, which is driving a rise in sea levels in tidal waters, is partially to blame for Stumpy’s fate.

“Portions of the seawalls have settled as much as five feet since their initial construction from the late 1800s to the early 1900s,” the Park Service said. “As a result of the settling and sea level rise, water flows over portions of the seawalls twice a day during normal tidal conditions.”

Mike Litterst, communications chief for the National Mall and Memorial Parks, said the announcement of the sea wall repair and tree removal was purposely made before the cherry blossom bloom this year so people could travel to the Tidal Basin and visit Stumpy one last time during peak bloom. He expects huge crowds at peak bloom next week.

Mike Litterst, communications chief for the National Mall and Memorial Parks, at the Tidal Basin on Thursday. (Kevin Ambrose)

The Credit Union Cherry Blossom 10-mile and 5K will commemorate the beloved tree next month with its image on race T-shirts and race medals, and a full-size Stumpy mascot.

“This news [from the NPS] makes 2024 the perfect year for us to celebrate Stumpy,” Phil Stewart, director of the cherry blossom races, said in a news release.

Litterst said that the sea wall project will begin in May and that Stumpy and the rest of the trees will likely be cut down in June. Replanting mature trees is too costly and challenging, he said, particularly given the number of trees. Thus, removal is necessary.

Clippings from Stumpy will be sent to the National Arboretum to create genetic matches. The hope is to plant little Stumpy clones on the National Mall or nearby parks. The rest of Stumpy and the other trees will be ground into mulch and spread around the remaining cherry tree bases to protect their roots and provide nutrients to the soil. It’s the “circle of life,” Litterst said.

As of Thursday, Stumpy was at bloom stage 4 of 6, “peduncle elongation.” (Kevin Ambrose)
Stumpy, seen here in August 2022, is often flooded during high tide. (Kevin Ambrose)

On a sunny Thursday morning on the Tidal Basin, three news crews filmed the tree, and many tourists stopped to take photos. Litterst laughed as he noted that while the National Mall has so much to offer — with its impressive memorials, monuments, trees and history — people continually ask where they can find Stumpy, one of the Tidal Basin’s smallest and most distressed trees.

If you’re looking for Stumpy yourself, you can find it about a one-minute walk just to the west of the Jefferson Memorial. But you can also look for the crowd.

Stumpy with fall foliage in October 2022. (Kevin Ambrose)
Stumpy in the snow this past January. (Kevin Ambrose)

At Northwestern, students watch climate change through maple trees

March 8, 2024 · 3 minute read
At Northwestern, students watch climate change through maple trees
(Joshua A. Bickel / Associated Press)
Big Mama has seen a lot of students passing by in her 120 years. So have Little Mama, Big Bertha, Persephone, Doug and Grant — just some of the many sugar maple trees on Northwestern University’s campus that have provided not only sap, but also data to students doing a course on maple syrup and climate change.

It’s a class that the students, who come from majors ranging from environmental policy and journalism to civil engineering, say provides hands-on experience in data collection and a front-row seat to witness climate change. It’s also a highly sought-after course and one that students say more programs should emulate with its incorporation of Indigenous knowledge. Many current and former students are passionate about the environment and are keen on learning more about environmental justice and Native perspectives.

But less than one percent of Northwestern’s benefits-eligible staff in the 2020 and 2021 academic years identified as American Indian or Alaska Native — a statistic that follows a nationwide trend, which, as of fall of 2021, indicated that the same group made up less than one-half of one percent of college faculty in the U.S., according to the National Center for Education Statistics. Northwestern says it’s actively working to enhance its Native and Indigenous presence on campus, including through faculty recruitment, and is proud of the quality of its Indigenous faculty.

The maple course instructor, Eli Suzukovich III, is of the Little Shell Tribe of Chippewa/Cree and first came to the idea of tapping urban trees in 2012, when he was working for the American Indian Center in Chicago. He says he and his colleagues realized it was a good outdoor activity for winter and early spring, and built a curriculum around the practice. “It was largely for Native kids, as a way to think about climate change and environment from a Native perspective, but also thinking about Native traditions,” he said.

Now, he’s adapted that curriculum, in partnership with associate professor of chemistry Shelby Hatch, for Northwestern students, who have been taking the class for about seven years. “In seven years I’ve had seven different winters,” Suzukovich III said. “The only thing I can know that’s consistent is that the trees will produce sap at some point.”

This year, through hail and freezing rain, students calculated the trees’ heights. Next, they tapped through layers of bark to get to the sap that flows through their trunks, and tested the sugar content of that sap using a special tool called a refractometer. Eventually, they’ll boil into maple syrup what they catch in plastic containers duct taped to the side of each tree.

“I’ve loved this class and just the opportunity to learn through doing,” said Zella Milfred, a junior who grew up organizing around climate issues in Madison, Wisconsin. One of her fellow class project group members, sophomore Bela Filstrup, also grew up engaged in climate activism and says it was important to her to have a strong science background as well as to study connections between climate and environmental justice. “Getting to know your environment a lot more and having just so much more respect of the land, I think is really important,” she said.

Forrest Bruce, a former student of the class who is now a fifth-year Ph.D. candidate interested in climate change education for Native youth, also said he appreciated the course for allowing him to connect with the land and for its focus on adaptation.

“I think, like a lot of our young people are bombarded with this narrative that…you are the generation that is going to have to live through climate collapse,” Bruce said. “It’s important not to downplay the severity of the situation that we’re in, but also I think that cultivating climate anxiety like that can be paralyzing.”

He said that he doesn’t think the class should be exceptional and that more should be done to connect Indigenous education with climate curricula on campus.

“Our ancestors, they always found ways to adapt and to change with the times. And so we’re continuing that tradition,” he said.


Associated Press journalist Joshua A. Bickel contributed to this report.

World’s oldest fossilised trees discovered along Devon and Somerset coast

March 8, 2024 · 3 minute read
World’s oldest fossilised trees discovered along Devon and Somerset coast
The fossilised stump of a Calamophyton tree, discovered in the high sandstone cliffs along the Devon and Somerset coast. Part of the oldest known fossil forest on Earth, it is roughly four million years older than the previous record holder, which was found in New York state. Photograph: Neil Davies

The fossilised Calamophyton remains show how early trees helped shape landscapes and stabilise riverbanks millions of years ago

The world’s oldest fossilised trees, dating back 390m years, have been found in the high sandstone cliffs along the Devon and Somerset coast.

The fossilised trees are the oldest ever found, roughly 4m years older than the previous record holder, which was found in New York state.

The fossilised trees, known as Calamophyton, would resemble palm trees if seen from a distance, but were a “prototype” of the kinds of tree we are familiar with today. Rather than solid wood, their trunks were thin and hollow in the centre and they stood between 2 and 4 metres tall. They also lacked leaves; their branches were covered in hundreds of twig-like structures.

The fossils were found near Minehead, on the south bank of the Bristol Channel, near what is now a Butlin’s holiday camp.

“This was a pretty weird forest – not like any forest you would see today,” said Prof Neil Davies, a geologist at the University of Cambridge and the study’s first author. “There wasn’t any undergrowth to speak of and grass hadn’t yet appeared, but there were lots of twigs dropped by these densely packed trees, which had a big effect on the landscape.”

Scientists had previously assumed that this stretch of the English coast did not contain significant plant fossils, but this find shows how early trees helped shape landscapes and stabilise riverbanks and coastlines hundreds of millions of years ago. The results are reported in the Journal of the Geological Society.

Forest of Calamophyton trees
A forest of Calamophyton trees. The trees were a ‘prototype’ of the kinds we are familiar with today. Photograph: Peter Giesen/Chris Berry

The forest dates back to the Devonian period, between 358m and 419m years ago, when life started its first big expansion on to land. By the end of the period, the first seed-bearing plants had appeared and the earliest land animals, mostly arthropods, were well established.

“The Devonian period fundamentally changed life on Earth,” said Davies. “It also changed how water and land interacted with each other, since trees and other plants helped stabilise sediment through their root systems, but little is known about the very earliest forests.”

The fossil forest identified by the researchers was found in the Hangman sandstone formation, along the north Devon and west Somerset coasts. During the Devonian period, this region was not attached to the rest of England, but instead lay farther south, connected to parts of Germany and Belgium, where similar Devonian fossils have been found.

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“When I first saw pictures of the tree trunks, I immediately knew what they were, based on 30 years of studying this type of tree worldwide,” said Dr Christopher Berry, a palaeobotanist at Cardiff University and the study’s co-author. “It was amazing to see them so near to home. But the most revealing insight comes from seeing, for the first time, these trees in the positions where they grew.

“It is our first opportunity to look directly at the ecology of this earliest type of forest, to interpret the environment in which Calamophyton trees were growing, and to evaluate their impact on the sedimentary system.”

The fieldwork was undertaken along the highest sea cliffs in England, some of which are accessible only by boat, and revealed that this sandstone formation is in fact rich with plant fossil material from the Devonian period.

During that era, the site was a semi-arid plain, crisscrossed by small river channels spilling out from mountains to the north-west. The emergence of the first tightly packed clusters of trees would have affected the way that rivers flowed across the landscape, the researchers said. “People sometimes think that British rocks have been looked at enough, but this shows that revisiting them can yield important new discoveries,” said Davies.

‘Living fossil’ tree frozen in time for 66 million years being planted in secret locations

March 1, 2024 · 3 minute read
‘Living fossil’ tree frozen in time for 66 million years being planted in secret locations
Wollemi pines — thought to have gone extinct 2 million years ago — were rediscovered in 1994. Scientists are now hoping to reintroduce the species in the wild in a conservation effort that could take centuries.

Scientists are planting “living fossil” trees in secret locations in a bid to bring back the lost species from the brink of extinction — an effort that could take centuries.

Wollemi pines (Wollemia nobilis) were believed to have disappeared some 2 million years ago. Fossils of the species dating the Cretaceous period (145 million to 66 million years ago) show they have barely changed in appearance since this time.

But in 1994, hikers in Australia’s Blue Mountains stumbled upon a relict stand of these ancient conifers. Now, only around 60 of them remain in Wollemi National Park. They are threatened by Phytophthora cinnamomi, a pathogenic water mold that causes dieback, and by rampant wildfires that intermittently rage through this region of New South Wales.

Since its rediscovery, wollemi pines have been grown in botanical gardens and private spaces around the world. And the Wollemi Pine Recovery Team, a partnership between Australian government scientists and conservationists, has begun the process of reintroducing seedlings to three sites in Wollemi National Park.

“The sites comprise high-elevation sandstone gorges that are sufficiently deep, narrow and steep-sided to provide refugia from frequent, intense wildfires and drought,” representatives said in a statement emailed to Live Science. “There was no evidence of infection with pathogenic Phytophthora species at either site when surveyed immediately prior to the translocations, and there is a low (but non-zero) likelihood of unauthorized visitation due to their remoteness.”

Following a pilot transplantation effort in 2012, the recovery team initiated a more intensive project in 2019. Over 400 saplings were transplanted at two sites and — due to drought conditions — the team later hauled several thousand gallons of water to the plants in order to help them survive. Later that year, a substantial number of the trees were destroyed by bushfires. Only 58 saplings made it to 2023.

The trees were found in 1994 by hikers in the Blue Mountains in New South Wales.  (Image credit: AndriiSlonchak via Getty Images)

In 2021, 502 more Wollemi pines were planted at the sites to replace those lost in the fires. “Survival has greatly exceeded expectations, due in part to several years of favorable La Niña conditions following the 2021 population augmentations,” the researchers said. La Niña is a periodic climate pattern that features colder-than-average waters in the central and east-central equatorial Pacific. Increased rainfalls due to the climatic phenomenon benefited the new transplants—but that seems to be coming to an end. Landslides caused by heavy rains in 2022 led to further fatalities but more than 80% survived. More will be planted in 2024.

The team has taken extensive steps to prevent introduction of Phytophthora to the sites. Their locations are concealed from the public and even the reintroduction team limits their time near the plants. They repeatedly disinfect their shoes to reduce the likelihood they will track in traces of the water mold. Even a few spores might spell death for this nascent population.

They have also intentionally located some of the young trees in areas that might be subject to bushfires “to help address knowledge gaps regarding their response and ability to tolerate fire,” the team said.

While the new populations are being intensively monitored, the fate of the species in the wild is far from assured. The young trees grow less than 0.4 inches (1 centimeter) a year, so it will take decades for them to reach maturity and produce seeds. Some may produce offshoots in the meantime, though when they may begin propagating themselves in this fashion remains unknown.

Fires and other climate-related issues such as reduced rainfall are likely to interfere with the restoration effort in the coming years. The scientists view their effort as a multi-generational one: a new cohort of stewards will need to take their place in the ensuing decades.

“To be successful, the translocated populations must become self-sustaining, and the benchmark is the appearance of second-generation seedlings,” the researchers said. “Given the slow growth and maturation of Wollemi pines in the wild, this is likely to take many decades, if not centuries. Given predicted increases in the frequency and severity of fire and drought due to climate change — arguably the two greatest threats to these populations — their long-term security is far from guaranteed.”

Ancient Pollen Trapped in Greenland Ice Uncovers Changes in Canadian Forests Over 800 Years

March 1, 2024 · 6 minute read
Ancient Pollen Trapped in Greenland Ice Uncovers Changes in Canadian Forests Over 800 Years

The new study helps illuminate how changes in forest composition followed European settlement and natural changes in climate.

Reno, Nev. (February 8, 2024) – The Greenland ice sheet lies thousands of miles from North America yet holds clues to the distant continent’s environmental history. Nearly two miles thick in places, the ice sheet grows as snow drifts from the sky and builds up over time. But snow isn’t the only thing carried in by air currents that swirl around the atmosphere, with microscopic pollen grains and pieces of ash mixing with snowfall and preserving records of the past in the ice. A new study examined these pollen grains and identified how eastern Canada’s forests grew, retreated, and changed through time.

Published January in the journal Geophysical Research Letters, the research was led by Sandra Brugger, Ph.D., during her postdoctoral work with Joe McConnell, Ph.D., in DRI’s Ice Core Lab. Although the lab has conducted many studies using cores of ice extracted from Arctic landscapes around the world—using the chemical signals trapped in the ice and air bubbles to track changes in environmental and human history—this is the first time that pollen was the center of focus. Through painstaking analysis of each pollen grain under the microscope, they found a record of forest changes spanning 850 years, covering both the onset of the Little Ice Age around 1400 and the arrival of European settlers and subsequent intensive logging practices around 1650. The information not only provides glimpses of the past, but can help establish baselines for evaluating changes in forest cover as the global climate warms.

Dr. Brugger examining a sample of pollen under the microscope.
Dr. Sandra Brugger examining a sample of concentrated ancient pollen extracted from an ice core that preserved atmospheric particles over 850 years. Photo credit: Jessi LeMay/DRI.

“Our results are exciting because pollen that traveled thousands of miles can illuminate changes that happened on a large scale in those forests,” said Brugger, who is now at the University of Basel.

Because pollen is relatively large compared to other atmospheric particles, few pollen grains travel across oceans and get preserved in Arctic ice sheets. In order to obtain enough pollen to piece together the story of historic forest changes, Brugger developed new methods that made the analysis possible, involving carefully evaporating water from the ice core to collect the miniscule grains of pollen. This study marks one of the first times that pollen has been extracted from polar ice cores to examine environmental change over time. Pollen in lake sediment has been used for the same purpose but is reflective of a local ecosystem immediately surrounding the lake, and does not capture changes in vegetation occurring on a region-wide scale.

“We also get a more precise chronology from the ice cores than from most lake sediments, because we can date them almost to the year,” Brugger said. “This helps tie the information to, for example, European settlers coming to eastern North America, because we know from historic sources when they arrived and what they did to the landscape.”

Dr. Brugger holding a slide with pollen grains visible.
Dr. Brugger holding a microscope slide with pollen grains collected from the ice core. Photo credit: Jessi LeMay/DRI.

“Since Greenland is only sparsely vegetated at the margins of the ice sheet and so far from forested regions, we don’t usually think about trying to measure pollen in Greenland ice cores,” said Nathan Chellman, Ph.D, assistant research professor at DRI and co-author of the study. “It is pretty incredible to think that the history of North American conifer forests can be told by measuring the few pollen grains that manage to make it through the atmosphere to the ice sheet.”

Joining DRI’s Ice Core Lab to conduct the work allowed Brugger to utilize McConnell’s decades of expertise developing and honing techniques for making precise chemical measurements of ice cores to pinpoint specific events in time, including plagues, volcanic eruptions, and the evolution of industrial society.

The ice core was collected from southern Greenland and held pollen primarily from conifer forests on the North Atlantic coast, with smaller amounts from northern tundra vegetation and European forests. Between approximately 1160 and 1400, a period known as the Medieval Warm Period, about 60% of the pollen records came from northern forest species such as pine, spruce, and fir. After the onset of the Little Ice Age circa 1400, the same species compose nearly 80% of the pollen record, demonstrating an expansion of these forests as the climate cooled. Because there is no evidence that the northernmost tree line shifted over this timeframe, the forest spread likely came from changes in forest density, pollen productivity, and a southward expansion into more temperate regions, the authors write.

Pollen from the same conifer species changed again between 1650 and 1760, declining to about 40% of the ice record, which is likely due to extensive logging of the region by European settlers during this time. The study authors ruled out increased forest fires as the cause of the decline by measuring fire indicators like charcoal and black carbon in the ice core. They also cross-referenced their findings with historical records showing that white pine forests were considered valuable timber, leading to many of the forests along the Miramichi, Saint John, and Ottawa rivers to be harvested by 1850.

Image of a pine pollen grain as viewed under a microscope.
A pine pollen grain (Pinus sp.) collected from the ice core and examined under the microscope. Photo credit: Jessi LeMay/DRI.

Around 1760, chemical signatures of fossil fuel pollution began appearing in the ice record, marking the start of industrialization in eastern North America. This is around the time when the pollen record reflects changes in human activities more prominently than climatic influences, suggesting the start of a human-driven ecosystem in the region. Conifer forests then declined further at the beginning of the 20th century, with continued logging and clearing of forests for farmland throughout eastern Canada. At the same time, pollen records show an increase in ragweed, a shrub known to proliferate in disturbed landscapes. The pollen record indicates that pine forest recovery started around 1950, when a decline in logging coincided with rural farm abandonment and a shift in climate.

“This clarity of the signal showing pine forest expansion at the beginning of the Little Ice Age, and then this retraction once the Little Ice Age is over, and then human impact coming in — you see this on a large scale,” Brugger said. “I did not expect the story to be so clear in the ice.”

This study follows previous work by Brugger on another ice core from central Greenland, where the pollen record was markedly different from this southern Greenland ice core. This is because the two locations receive different atmospheric particles, Brugger says. The central Greenland ice core recorded more changes in Arctic vegetation than more distant locales.

The team also worked with colleagues in Vienna to create computer models that could simulate the movement of pollen through the atmosphere. This allowed them to better understand and verify where each Greenland site is positioned within global atmospheric circulation patterns.

“This southern ice core really tracked the boreal forest,” Brugger said. “You get a completely different signal than with the previous study I did in central Greenland, where we tracked changes in the Arctic. These two ice core sites track very, very different things and it’s all confirmed by atmospheric models, which is beautiful.”

Studies like this offer a deeper understanding of environmental history that can also be applied to future changes in climate. Brugger plans to continue using ancient pollen to glimpse into the past, and is working on publishing the results of another study with a much deeper ice core that represents 8,000 years of history.

More Information: The full study, Pollen in Polar Ice Implies Eastern Canadian Forest Dynamics Diverged From Climate After European Settlement, is available from Geophysical Research Letters at

Study authors includeSandra Brugger (DRI/U. of Basel), Nathan Chellman (DRI), Andreas Plach (U. of Vienna), Paul Henne (USGS), Andreas Stohl (U. of Vienna), Joseph McConnell (DRI)

Country diary: Caught in a web of late winter branches

February 22, 2024 · 2 minute read
Country diary: Caught in a web of late winter branches

‘Before the riot of unfurling, and of green, there is a clear, and no less striking, shape to the darkness.’ The palm house at Kew Gardens in winter. Photograph: Ellen Rooney/Alamy

Kew Gardens, London: Before these wonderful trees are graced once more with spring leaves, we must appreciate their shadow portraits.

Before the deciduous trees come into leaf, walking underneath them is dizzying. It is like moving through a large, deconstructed nest – one that expands from tree to tree. Without leaves, the nest is airy and flooded with light, made from whole branches and lined with the sky.

The trees lose some of their familiarity when leaves do not reveal their names, and it is their silhouettes that speak. A crown of fine twigs reveals a beech. The horse chestnut’s branches, upturned at the ends, hang like chandeliers. There is something intimate about moving through these shadow portraits, seeing a level of exposure that is not, for most of the year, available. There is an invitation to drift under all this uplift, to trace new pathways through wooden cobwebs.

A large English oak draws me to a standstill. For a moment, I am caught in the web as I follow the outstretched branches. High up, a larch’s twigs brush against its own; lower down, sun soaks the bark in bronze. The width of the trunk denotes an old age, and with many oaks of this kind not producing acorns until they are more than 40 years old, there is a message of slow and steady growth fitting to the season preceding the sudden spurts of spring.

Although there are other silhouettes to trace, it is here that I stay as the sky streams through the branches. I stay as the blue, without leaves to hide it, is at its brightest. A green woodpecker chatters from the larch and a jay flashes turquoise feathers as it passes. I stay until the cold forces me to move.

At ground level, there are scatterings of snowdrops and winter aconite. A little higher, camellias pour in colour from the fringes. Higher still, red catkins dangle from the hazel. The message of coming brightness is clear. Yet, just before the showiness begins, before the riot of unfurling and of green, there is a clear, and no less striking, shape to the darkness, looking skywards through webs of bare branches.

Very cool: trees stalling effects of global heating in eastern US, study finds

February 22, 2024 · 3 minute read
Very cool: trees stalling effects of global heating in eastern US, study finds

Vast reforestation a major reason for ‘warming hole’ across parts of US where temperatures have flatlined or cooled

Trees provide innumerable benefits to the world, from food to shelter to oxygen, but researchers have now found their dramatic rebound in the eastern US has delivered a further, stunning feat – the curtailing of the soaring temperatures caused by the climate crisis.

While the US, like the rest of the world, has heated up since industrial times due to the burning of fossil fuels, scientists have long been puzzled by a so-called “warming hole” over parts of the US south-east where temperatures have flatlined, or even cooled, despite the unmistakable broader warming trend.

A major reason for this anomaly, the new study finds, is the vast reforestation of much of the eastern US following the initial loss of large numbers of trees in the wake of European settlement in America. Such large expanses have been reforested in the past century – with enough trees sprouting back to cover an area larger than England – that it has helped stall the affect of global heating.

“The reforestation has been remarkable and we have shown this has translated into the surrounding air temperature,” said Mallory Barnes, an environmental scientist at Indiana University who led the research. “The ‘warming hole’ has been a real mystery and while this doesn’t explain all of it, this research shows there is a really important link to the trees coming back.”

There was a surge in deforestation from the start of the US’s early colonial history, as woodland was razed for agriculture and housing, but this began to reverse from around the 1920s as more people began to move into cities, leaving marginal land to become populated again with trees. The US government, meanwhile, embarked upon an aggressive tree-planting program, with these factors leading to about 15m hectares of reforested area in the past century in the eastern US.

people work in a forest
People work to reforest Allegheny National Forest in Pennsylvania circa 1934. Photograph: Universal History Archive/Universal Images Group via Getty Images

The recovery of the US’s eastern forests has blunted global heating mainly through the trees’ transpiration, in which water is drawn up through the roots to the leaves and then released into the air as vapor, slightly cooling the surrounding area.

By poring over data from satellites and weather stations located across the eastern US from 1900 to 2000, Barnes and her colleagues found reforested areas have provided this cooling impact on a grand scale, with most of this effect occurring within 400 meters of the trees.

In all, the replenished forests today cool the eastern US by 1C to 2C (1.8F to 3.6F) each year. The cooling effect is strongest on the hottest days in summer, when trees lower temperatures by 2C to 5C (3.6F to 9F), the researchers found.

The researchers cautioned that bringing back trees hasn’t been the sole cause of the stalled warming, with factors such as airborne pollutants, which block incoming sunlight, and agricultural irrigation also potential causes. But Barnes said that the findings should further bolster efforts to provide thoughtful reforestation, particularly near urban communities that suffer particularly scorching temperatures due to a lack of shady trees.

“Trees have a really beneficial impact upon surface temperatures through transpiration, which is similar to human sweating, and they have really cooled things off a lot,” said Barnes.

People plant trees
Civilian Conservation Corps workers plant 15,000,000 trees across the wastelands of southern Mississippi on 11 April 1940. They are part of the United Forest Service which will re-establish forests destroyed by logging and lumbering operations decades ago. Photograph: AP

“Moving forward, we need to think about tree planting not just as a way to absorb carbon dioxide but also the cooling effects in adapting for climate change, to help cities be resilient against these very hot temperatures.”

Patrick Gonzalez, a University of California, Berkeley, climate change scientist and forest ecologist who wasn’t involved in the new study, said the work provides “strong support” to the theory of cooling trees.

“Cutting carbon pollution from cars, power plants and other human sources that burn coal, oil and methane remains the essential solution to halt climate change,” he said. “Natural regeneration of trees and reforestation, where ecologically appropriate, can contribute substantially.”

Barnes, too, stressed that reforestation was no substitute for the need to drastically cut planet-heating emissions, which hit a new global high last year.

“Nature-based climate solutions like tree planting won’t get us out of this climate change problem,” she said. “If anyone thinks we can just plant a few trees and be OK, they are wrong – we need a massive reduction in fossil fuel emissions to hit our targets. Reforestation is something that needs to happen in addition to, not instead of, cutting emissions.”

Is the Amazon forest approaching a tipping point?

February 16, 2024 · 2 minute read
Is the Amazon forest approaching a tipping point?

Global warming may be interacting with regional rainfall and deforestation to accelerate forest loss in the Amazon, pushing it towards partial or total collapse

Research published today in Nature, has identified the potential thresholds of these stressors, showing where their combined effects could produce a ‘tipping point’ – in which the forest is so fragile that just a small disturbance could cause an abrupt shift in the state of the ecosystem.

The study was led by the Federal University of Santa Catarina in Brazil, and includes experts from the University of Birmingham. Its authors hope that by understanding the most important stressors on the rainforest environment, they can develop a pathway for keeping the Amazon forest resilient.

Lead author Bernardo Flores, from the University of Santa Catarina, said: “Compounding disturbances are increasingly common within the core of the Amazon. If these disturbances act in synergy, we may observe unexpected ecosystem transitions in areas previously considered as resilient, such as the moist forests of the western and central Amazon.”

We have evidence showing that rising temperatures, extreme droughts and fires are can affect how the forest functions.

Dr Adriane Esquivel-Muelbert, Birmingham Institute of Forest Research

These ecosystem transitions could include a forest that may be able to recover but is still trapped in a degraded state and dominated by opportunistic plants such as bamboos and vines, or a forest that is unable to recover and remains trapped in an open-canopy, flammable state.

The research findings are important because of the vital role the Amazon plays in the global climate system. For example, Amazonian trees store massive amounts of carbon which, if released, could accelerate global warming. showed that the Amazon temporarily to act as a carbon sink during the 2015 drought.

Co-author, Dr Adriane Esquivel-Muelbert from the Birmingham Institute of Forest Research, said: “We have evidence showing that rising temperatures, extreme droughts and fires are can affect how the forest functions and change which tree species can integrate the forest system. With the acceleration of global change there’s an increasing likelihood that we will see positive feedback loops in which, rather than being able to repair itself, the forest loss becomes self-reinforced.”

The study also examined the roles of biodiversity and local communities in shaping Amazonian forest resilience. They argue that successful approaches will depend on a combination of local and global efforts. This will include cooperation between Amazonian countries to end deforestation and expand restoration, while global efforts to stop greenhouse gas emissions mitigate the effects of climate change.

During the recent COP28 Climate Conference, the team published a set of policy briefs setting out steps that local, regional and global organisations need to take to prevent the Amazon from reaching a tipping point.

  • For media enquiries please contact Beck Lockwood, Press Office, University of Birmingham, tel: +44 (0)781 3343348.
  • Flores et al. (2024) “Critical transitions in the Amazon forest system”, Nature, DOI:10.1038/S41586-023-06970-0.
  • Other research references:
    Bennett et al. (2018) “Sensitivity of South American tropical forests to an extreme climate anomaly”, Nature Climate Change,
    Esquivel-Muelbert et al. (2018) “Compositional response of Amazon forests to climate change”, Global Change Biology,
  • The University of Birmingham is ranked amongst the world’s top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 8,000 international students from over 150 countries.

Ill-judged tree planting in Africa threatens ecosystems, scientists warn

February 16, 2024 · 2 minute read
Ill-judged tree planting in Africa threatens ecosystems, scientists warn

Research reveals area size of France is under threat by restoration projects taking place in unsuitable landscapes.

Acacia trees in northern Turkana, Kenya. The research found that 52% of tree-planting projects in Africa are occurring in savannahs, with almost 60% using non-native species. Photograph: Muntaka Chasant/Rex/Shutterstock

Misguided tree-planting projects are threatening crucial ecosystems across Africa, scientists have warned.

Research has revealed that an area the size of France is threatened by forest restoration initiatives that are taking place in inappropriate landscapes.

One project in particular, the African Forest Landscape Restoration Initiative, aims to plant trees across 100m hectares (247m acres) of land by 2030. Scientists have warned that the scheme plans to plant trees in non-forest ecosystems such as savannahs and grasslands, potentially disrupting or destroying intact ecosystems.

The research found that 52% of tree-planting projects in Africa are occurring in savannahs, with almost 60% using non-native tree species, which also brings the risk of introducing invasive species.

The researchers say the misclassification of grassy ecosystems including savannahs as “forests” could lead to misplaced reforestation and destruction of these ancient grasslands.

The definition currently used by the UN’s Food and Agriculture Organization defines forests as areas of land spanning more than 0.5 hectares with trees higher than 5 metres, with tree canopy cover of at least 10%.

Under this definition, open-spaced ecosystems with trees, such as savannahs, would be classified as forests and would meet the required standards for reforestation – even if they were not appropriate.

The addition of more trees to these areas creates more canopy cover and decreases the amount of light that can reach the ground below, which can change the grassy environment of the savannah. This could be a risk to wildlife such as rhinos and wildebeest, as well as people who depend on these ecosystems.

“We must act to avoid a situation where we cannot see the savannah for the trees, and these precious grassy systems are lost irrevocably,” wrote the authors.

Kate Parr, a professor of tropical ecology at the University of Liverpool and an author of the study, published in the journal Science, said: “Restoration of ecosystems is needed and important, but it must be done in a way that is appropriate to each system. Non-forest systems such as savannahs are misclassified as forest and therefore considered in need of restoration with trees.

“There is an urgent need to revise definitions so that savannahs are not confused with forest because increasing trees is a threat to the integrity and persistence of savannahs and grasslands.”

Dr Nicola Stevens, a researcher in African environments at the University of Oxford and co-author of the paper, said: “The urgency of implementing large-scale tree planting is prompting funding of inadequately assessed projects that will most likely have negligible sequestration benefits and cause potential social and ecological harm.”

Complex tree canopies help forests recover from moderate disturbances

February 9, 2024 · 4 minute read
Complex tree canopies help forests recover from moderate disturbances

An example of a complex forest canopy at the Mountain Lake Biological Station in Virginia. The station is part of the National Science Foundation’s National Ecological Observatory Network. (Photo provided by Jeffrey Atkins, USDA Forest Service)

WEST LAFAYETTE, Ind. — Extreme events wipe out entire forests, dramatically eliminating complex ecosystems as well as local communities.

Researchers have become quite familiar with such attention-grabbing events over the years. They know less, however, about the more common moderate-severity disturbances, such as relatively small fires, ice storms, and outbreaks of pests or pathogens.

“Since they’re more common, they’re probably playing a larger role in the ecosystem than we might have appreciated before,” said Brady Hardiman, associate professor of forestry and natural resources and environmental and ecological engineering in Purdue University’s College of Agriculture. “At any given time, a huge fraction of the forested landscape is undergoing or regrowing from a moderate-severity disturbance, which took out some of the trees but not all of them. The forest is not regrowing from scratch.”

A paper published in the Journal of Ecology by Purdue University researchers and their co-authors has identified how moderate-severity disturbances leave different patterns of change in the forest canopy structure. Hardiman and his colleagues based their findings on lidar (light detection and ranging) data collected at five sites of the National Science Foundation’s National Ecological Observatory Network in New Hampshire, Massachusetts, Virginia and Tennessee.

“The most interesting finding from this study is that the multitemporal lidar data can detect subtle signals of the disturbances,” said the paper’s lead author, Dennis Heejoon Choi, a Purdue postdoctoral scientist.

NEON began collecting data about 10 years ago. Repeat observations at specific forest sites of the type that NEON collects are still relatively rare, especially on a continental scale.

“NEON is a big sampling initiative,” said co-author Elizabeth LaRue, assistant professor of biological sciences at the University of Texas at El Paso. “It’s a big deal that now we have data to do something like this over time.”

Forest canopy structural dimensions include height, openness, density and complexity. Previous research by Hardiman and others has documented that structurally complex canopies absorb more light and that their complexity is linked to important ecosystem functions. These include nutrient cycling, providing shelter and nutrients to organisms, and biodiversity.

Comparing an old-growth forest to a Christmas tree farm offers a simple contrast in complexity, noted LaRue, a Purdue PhD alumna. Trees on a farm, planted in rows at about the same time, are all approximately the same age and height. An old-growth forest, meanwhile, shows far more variation with trees of different sizes, ages, species and shapes.

“You can measure things that might be equivalent to a block of cheese,” she said. “A block of Swiss cheese would be more complex than, say, a block of cheddar. Some of the metrics we use essentially measure how many holes you have in your block of forest.”

The researchers analyzed the differences between press and pulse disturbances, discrete events compared to those that occur over a longer period. The co-authors looked for patterns in changes to canopy structure following disturbances. They found that forests with canopy structures of more complexity seemed better able to withstand and recover from the disturbances.

“Canopy structure is something we can modify through management activities,” Hardiman said. “Managing forests to promote structural complexity could make them more resilient to a variety of disturbances in ways that allow our forests to continue growing following those disturbances.”

Wrangling the NEON data was a computationally intensive process that required the resources of Purdue’s Rosen Center for Advanced Computing. The process included accounting for the changes in lidar technology and differing sensor configurations used over the years. Newer lidar systems with stronger beams generate denser point clouds, the 3D data sets that represent the shape of the forest canopies.

“We tried to homogenize the point density equally year by year to make comparative metrics,” Choi said. The challenge was to balance the enhanced measurement capabilities of newer sensors with the need for consistency and comparability across time, he noted.

The work is part of the Institute for Digital Forestry’s effort to develop new tools and methods that will allow researchers to measure individual trees more often, in more detail, and to expand their measurements globally.

The institute brings together forest ecologists and foresters with computer scientists and engineers. Their combined expertise and perspectives provide a foundation for innovation by thinking about old questions in new ways and developing tools that allow them to ask new questions.

This work was funded by the National Science Foundation and the U.S. Department of Agriculture Forest Service. Also contributing to the Journal of Ecology paper were Purdue’s Songlin Fei and Bina Thapa; Jeff Atkins, USDA Forest Service; Jane Foster, University of Vermont; Jaclyn Hatala Matthes, Harvard Forest; and Robert Fahey, University of Connecticut.

About Purdue University

Purdue University is a public research institution demonstrating excellence at scale. Ranked among top 10 public universities and with two colleges in the top four in the United States, Purdue discovers and disseminates knowledge with a quality and at a scale second to none. More than 105,000 students study at Purdue across modalities and locations, including nearly 50,000 in person on the West Lafayette campus. Committed to affordability and accessibility, Purdue’s main campus has frozen tuition 13 years in a row. See how Purdue never stops in the persistent pursuit of the next giant leap — including its first comprehensive urban campus in Indianapolis, the new Mitchell E. Daniels, Jr. School of Business, and Purdue Computes — at

Writer: Steve Koppes

Media contact: Maureen Manier,

Sources: Brady Hardiman,; Dennis Heejoon Choi,; Elizabeth LaRue,

In Uganda, refugees’ need for wood ravaged the forest. Now, they work to restore it

February 9, 2024 · 5 minute read
In Uganda, refugees’ need for wood ravaged the forest. Now, they work to restore it
A sapling is held before it is planted inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)

NAKIVALE, Uganda (AP) — Enock Twagirayesu was seeking sanctuary when he and his family fled violence in Burundi, and they found it in Uganda, the small East African nation that has absorbed thousands of refugees from unsettled neighbors.

Twagirayesu’s family has grown from two children when they arrived more than a decade ago to eight now, a boon for the family but also a marker of the immense pressure the Nakivale Refugee Settlement has put on the landscape near the Tanzania border.

What was wide forest cover two decades ago is now mostly gone, cut down for cooking fuel. When Twagirayesu saw women digging up roots to burn a few years ago, he knew it was time to act.

People, part of the Nakivale Green Environment Association, plant trees inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
People, part of the Nakivale Green Environment Association, plant trees inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
People, part of the Nakivale Green Environment Association, prepare to plant trees inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)
People, part of the Nakivale Green Environment Association, prepare to plant trees inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)

“We saw that in the days to come, when the trees are finished, we will also be finished,” he said. “Because if there are no trees to be used for cooking even the people cannot survive.”

He and two other refugees began planting trees in 2016, and Twagirayesu, who had sewn for a living back home, turned out to have a gift for mobilizing people. That early group quickly grew, and he now leads the Nakivale Green Environment Association to carry out what Twagirayesu calls the urgent business of reforesting.

“A tree is not like beans or maize, which you plant and tomorrow you will get something to eat. Planting trees is challenging,” he said.

The lands surrounding Nakivale, a refugee settlement in Uganda, have been heavily deforested due to both human activity and climate change. But a group of refugees is busy taking environmental matters into their own hands. (AP video shot by Patrick Onen, production by Joshua A. Bickel) (Jan. 13)

Deforestation is a national issue in Uganda, where most people use firewood for cooking, trees are often cut to make charcoal for export and some forests fall to illegal logging. The country has lost 13% of its tree cover since 2000, according to Global Forest Watch.

Nakivale, sparsely populated by locals, is one of the few territories in Uganda that could accommodate many refugees. More than 180,000 live there now, with regular new arrivals.

They come from neighboring countries such as Congo, where sporadic violence means an influx of arrivals heading toward Nakivale. There are Rwandan refugees still living in Nakivale who first arrived there shortly after the 1994 genocide. After the refugees are registered, they are allocated small plots of land upon which they can build homes and plant gardens.

Enock Twagirayesu, team leader of Nakivale Green Environment Association, and Cleous Bwambale, of United Nations High Commissioner for Refugees, tours trees planted by Twagirayesu and others at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, team leader of Nakivale Green Environment Association, and Cleous Bwambale, of United Nations High Commissioner for Refugees, tours trees planted by Twagirayesu and others at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)

Enock Twagirayesu, right, team leader of Nakivale Green Environment Association checks sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, right, team leader of Nakivale Green Environment Association checks sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, team leader of Nakivale Green Environment Association, checks a sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, team leader of Nakivale Green Environment Association, checks a sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)

Nsamizi Training Institute for Social Development, a local organization, is supporting the tree-planting activities of Twagirayesu and others. The institute’s yearly goal is to plant 300,000 trees, with about 3 million planted in recent years, said Cleous Bwambale, who is in charge of monitoring and evaluation for the institute.

On one recent afternoon, a group of refugees were busy planting thousands of pine seedlings on the rocky, steep side of a hill facing the Kabahinda Primary School. In scorching heat, they attacked solid ground with pickaxes and hoes before carefully tucking the seedlings into the earth. Nearly all of the workers have children enrolled at the government-owned but donor-supported school.

Deputy Headteacher Racheal Kekirunga said heavy rains in the valley bring the school to a standstill as stormwater races down the hill and runs through the yard, forcing teachers and students to stay inside.

“We hope that when we plant these trees it will help us to reduce on the running water that could affect our school, and our school gardens,” Kekirunga said. “Especially our learning and teaching. When the rain is too heavy, you must wait until it reduces and then you go to class.”

Cleous Bwambale, right, of United Nations High Commissioner for Refugees (UNHCR) talks to members of the Nakivale Green Environment Association during a field visit at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Cleous Bwambale, right, of United Nations High Commissioner for Refugees (UNHCR) talks to members of the Nakivale Green Environment Association during a field visit at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)

A refugee prepares to plant a tree inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
A refugee prepares to plant a tree inside Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Refugees are helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)

The Nsamizi institute, serving as an implementing partner in Nakivale for the U.N. refugee agency, collaborates with mobilizers like Twagirayesu in four parts of the 185-square-kilometer (71-square-mile) settlement, according to the U.N. refugee agency. The institute encourages refugees with small cash payments for specific work done, maps out plans to reforest specific blocks of land and provides seedlings.

Twagirayesu said his group has planted at least 460,000 trees in Nakivale, creating woodlots of varying sizes and age. They include pine, acacia and even bamboo. That success has come despite fears among some in the settlement that the authorities, wanting to protect mature woodlots, one day might force the refugees to go back home.

Enock Twagirayesu, team leader of Nakivale Green Environment Association, checks a sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, team leader of Nakivale Green Environment Association, checks a sapling during his visit at Kakoma Central Nursery in Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)

“We got a problem because some people were saying that when they plant trees, they will be chased away,” he said. “Teaching people to plant trees also became a war. But right now, after they saw us continue to plant trees, saw us getting firewood, they began to appreciate our work.”

Twagirayesu said that while he isn’t done yet as a tree planter, “when we are walking in the places where we planted trees we feel much happiness.”

Enock Twagirayesu, team leader of Nakivale Green Environment Association, and Cleous Bwambale of United Nations High Commissioner for Refugees, tours trees planted by Enoch and others at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. Twagirayesu is among refugees helping to plant thousands of seedlings in hopes of reforesting the area. (AP Photo/Hajarah Nalwadda)
Enock Twagirayesu, team leader of Nakivale Green Environment Association, and Cleous Bwambale of United Nations High Commissioner for Refugees, tours trees planted by Enoch and others at Nakivale Refugee Settlement in Mbarara, Uganda, on Dec. 5, 2023. (AP Photo/Hajarah Nalwadda)

This ancient material is displacing plastics and creating a billion-dollar industry

February 5, 2024 · 7 minute read
This ancient material is displacing plastics and creating a billion-dollar industry
Alona Kozma piles cork at a farm in Coruche, Portugal. (Jose Sarmento Matos for The Washington Post)

CORUCHE, Portugal — The rhythmic noise of axes whacking trees echoes in the depths of the cork oak forest.

But in Coruche, a rural area south of the Tagus River known as Portugal’s “cork capital,” the bang of trees falling to the ground doesn’t follow the sound of the ax strokes. Instead, experienced workers carefully peel away the bark from the tree trunks.

This annual rite of extracting cork in the summer months has been around for thousands of years in the western Mediterranean. Egyptians, Persians, Greeks and Romans used the material to make fishing gear, sandals and to seal jugs, jars and barrels. As glass bottles gained popularity in the 18th century, cork became the preferred sealant because it is durable, waterproof, light and pliable.

Now cork is experiencing a revival as more industries look for sustainable alternatives to plastic and other materials derived from fossil fuels. The bark is now used for flooring and furniture, to make shoes and clothes and as insulation in homes and electric cars. Portugal’s exports reached an all-time high of 670 million euro ($728 million) in the first half of 2023.

But cork is more than a trendy green material. In addition to jobs, the forests where it grows provide food and shelter for animals, all while sequestering carbon dioxide. And unlike most trees grown commercially, cork oaks are never cut down, meaning their carbon storage capacity continues through the 200 years or more they live.

Clothes made of cork are displayed at the Cork Oak Observatory in Coruche. (Jose Sarmento Matos for The Washington Post)
How cork is harvested

With a firm swing, Fernando Tacha strikes the trunk of a cork oak, then twists his ax and uses the handle to delicately prise the plank.

“I started cutting cork when I was only 19. Now I’m 69. But I will do this as long as I can,” he says as he wipes the sweat from his forehead. “It’s a hard job, but a beautiful one.”

A low, slow-growing evergreen tree, the cork oak is endemic to the Mediterranean. The most extensive forests can be found on the Atlantic coast of the Iberian Peninsula. In Portugal, the world’s largest cork producer, the oaks are so cherished they were chosen as the country’s national tree and are protected by law, so it’s forbidden to cut them. Spain is the second-largest producer, followed by Morocco, Algeria, Tunisia, Italy and France.

An ax is used to cut the cork at a farm in Coruche. (Jose Sarmento Matos for The Washington Post)
Cork is harvested at the farm. (Jose Sarmento Matos for The Washington Post)

The process of harvesting cork takes precision and years of practice. The stroke of the ax must be strong, but also delicate to avoid hitting the inner bark and damaging the tree. Because it is so specialized, it’s one of the best paying agricultural jobs in Portugal.

The bark can only be harvested between late May and August, when the tree is in its active phase of growth, which makes it easier to strip the outer layer without damaging the tree trunk.

The cork oak is unique in its ability to regenerate its bark. Once it is removed, workers write the last number of that year with white paint on the exposed golden brown trunk — a three means it was harvested in 2023. The bark will slowly grow back and be ready for another harvest after nine years.

Paula Salgueira, who has been working in the cork harvest in Coruche for 35 years, extends her hand to touch an oak that was just stripped. “It’s cold,” she says as she caresses the smooth denuded trunk. While axmen work in pairs removing the cork, Salgueira and a few other women gather the planks in piles for transportation.

The planks will then be stacked outdoors in storage areas exposed to air and sunlight. After six months of aging to remove moisture, they will be sorted according to their thickness and quality, then boiled to clean impurities and make the material softer and easier to handle.

From bottle stopper to green material

While most cork is still used for bottle stoppers, over the last decade different industries have been finding new uses for it.

“We are seeing a growing interest in cork as a sustainable material,” says Rui Novais, a materials expert at the University of Aveiro in Portugal. “Compared with materials like polyurethane foam [used for thermal insulation], products made with cork require less energy and produce less CO2 emissions.”

The cork oak’s thick bark adapted to defend the tree from fire, making it a powerful insulating material that’s been used to shield fuel tanks on NASA spacecraft and electric car batteries. It’s also resistant to water and oil, and can withstand compression while retaining springiness.

“It’s an extraordinary, renewable and biodegradable material,” says Novais. “It’s also very durable. It has been demonstrated that cork products remain virtually unchanged for more than 50 years.”

Champagne cork stoppers are produced at the Amorim factory in Coruche. (Jose Sarmento Matos for The Washington Post)
Smoke rises from cork being boiled at the factory. (Jose Sarmento Matos for The Washington Post)

Part of the carbon absorbed by cork oak trees is transferred to cork products, which can be used for long periods, repurposed and recycled. Several studies found that cork is carbon negative, meaning it can store more carbon than what is required to produce it.

When cork planks are trimmed and punched to form natural cork stoppers, the leftovers are ground into granules and pressed together to form cork sheets or blocks. “Even cork dust is used to produce energy,” says João Rui Ferreira, secretary general of the Portuguese Cork Association. “It feeds the industry’s boilers and powers some of the production.”

Recycled cork can also be crushed and composited to make other products. In Portugal, Green Cork, a recycling program started by the environmental organization Quercus, has collected and recycled more than 100 million cork stoppers since 2009. A similar initiative, ReCORK, exists in the United States.

A natural factory

Most of the cork produced in Portugal grows in the gently undulating hills and plains in the south of the country, in an ancient agroforestry system known as montadoThis savannah-like ecosystem combines cork, holm oaks and olive trees with pastures, grazing livestock, crops and fallows.

“The soil in southern Portugal is very poor, there is very little rain and temperatures are very high in the summer,” says Teresa Pinto-Correia, a professor at the University of Évora in Portugal specializing in rural landscapes and agricultural systems. “But this kind of system is productive even when resources are scarce and conditions are difficult.”

For centuries, locals have preserved the montado because cork provided landowners with a source of income. This mosaic of habitats supports hundreds of species, including the Iberian lynx, the world’s most endangered wildcat, and the threatened Imperial eagle. One of the world’s oldest known cork oak trees, planted in 1783 in Águas de Moura, is known as “the whistler” because so many birds visit its large sprawling branches.

Iberian pigs feed on acorns and goats graze the interwoven pastures. Interspersing cork oak trees with animals and crops can boost production and biodiversity, but also build soil, control erosion, retain water, combat desertification and sequester carbon, says Pinto-Correia.

Cork is stacked at a farm. (Jose Sarmento Matos for The Washington Post)
Cork oak trees at a farm. (Jose Sarmento Matos for The Washington Post)

While the cork forests can help mitigate the effects of climate change, they are also increasingly at risk from it as drought and wildfires become more intense and more frequent in the region.

“The tree is adapted to the Mediterranean climate. The bark protects it from fire,” says forest engineer Conceição Santos Silva. “But for the first two years after cork is extracted, the trees are much more vulnerable to wildfires because they don’t have this protection.”

Yet fires in cork groves, she says, remain rare because of careful human management. “The tree always regenerates,” says Santos Silva.

As a slow-growing tree, the cork oak takes decades to provide shade and produce good quality cork. But in Coruche, people still go by an old Portuguese saying: “Those who care about their grandchildren plant cork oak trees.”

Rare ancient tree discovery has scientists ‘gobsmacked’

February 5, 2024 · 5 minute read
Rare ancient tree discovery has scientists ‘gobsmacked’

Trees are believed to have originated hundreds of millions of years agoEver since, evidence of these ancient plant sentinels has been in short supply.

Now, a new discovery of uniquely 3D tree fossils has opened a window into what the world was like when the planet’s early forests were beginning to evolve, expanding our understanding of the architecture of trees throughout Earth’s history.

Five tree fossils buried alive by an earthquake 350 million years ago were found in a quarry in the Canadian province of New Brunswick, according to a study published Friday in the journal Current Biology. The authors said these new and unusual fossil trees not only bear a surprising shape reminiscent of a Dr. Seuss illustration, they reveal clues about a period of life on Earth of which we know little.

“They are time capsules,” said Robert Gastaldo, a paleontologist and sedimentologist who led the study, “literally little windows into deep-time landscapes and ecosystems.”

Coauthors Olivia King and Matthew Stimson unearthed the first of the ancient trees in 2017 while doing fieldwork in a rock quarry in New Brunswick. One of the specimens they discovered is among a handful of cases in the entire plant fossil record — spanning more than 400 million years — in which a tree’s branches and crown leaves are still attached to its trunk.

Few tree fossils that date back to Earth’s earliest forests have ever been found, according to Gastaldo. Their discovery helps fill in some missing pieces of an incomplete fossil record.

“There are only five or six trees that we can document, at least in the Paleozoic, that were preserved with its crown intact,” said Gastaldo, a professor of geology at Colby College in Waterville, Maine.

Most ancient tree specimens are relatively small, he noted, and often discovered in the form of a fossilized trunk with a stump or root system attached. For his colleagues to find a preserved tree that could have been 15 feet tall in its maturity with an 18-foot diameter crown left the paleontologist “gobsmacked.”

This model rendering of the newly discovered Sanfordiacaulis tree includes simplified branching structure for easier visualization.

Ancient earthquake burial

The researchers excavated the first fossil tree about seven years ago, but it took another few years before four more specimens of the same plant were found in close proximity to one another. Dubbed “Sanfordiacaulis,” the newly identified species was named in honor of Laurie Sanford, the owner of the quarry where the trees were unearthed.

The forms taken by these previously unknown 350 million-year-old plants look somewhat like a modern-day fern or palm, per the study, despite the fact that those tree species didn’t appear until 300 million years later. But while the tops of ferns or palms as we know them boast few leaves, the most complete specimen of the newly discovered fossils has more than 250 leaves preserved around its trunk, with each partially preserved leaf extending around 5.7 feet (1.7 meters).

That fossil is encased in a sandstone boulder and roughly the size of a small car, according to Stimson, an assistant curator of geology and paleontology at the New Brunswick Museum.

The unique fossilization of the cluster of trees is likely due to a “catastrophic” earthquake-induced landslide that took place in an ancient rift lake, he said.

“These trees were alive when the earthquake happened. They were buried very quickly, very rapidly after that, at the bottom of the lake, and then the lake (went) back to normal,” Stimson said.

Finding complete fossil trees is rare and much less common than finding a complete dinosaur, according to Peter Wilf, a professor of geosciences and paleobotanist at Pennsylvania State University who was not involved with the study. Wilf noted via email that the “unusual” new fossil tree was a relic of a time period from which there are almost no tree fossils.

“The new fossils are a milestone in our understanding of how early forest structure evolved, eventually leading to the complex rainforest architectures that support most of Earth’s living biodiversity,” Wilf added.

‘Very Dr. Seuss’

To King, a research associate at the New Brunswick Museum who found the group of fossils, the Sanfordiacaulis would have looked like something plucked straight out of Dr. Seuss’ most popular works.

“You know in ‘The Lorax,’ the trees have these big pom-poms at the top and narrow trunks? These probably have a similar structure. You have this massive crown at the top, and then it does narrow and paper into this very small trunk,” King said. “It’s a very Dr. Seuss-looking tree. It’s a weird and wonderful idea of what this thing could look like.”

But the reign of the Sanfordiacaulis was short-lived, the researchers said. “We do not see this architecture of plant again,” Stimson told CNN. He noted that it grew in the early Carboniferous, a time period at the end of the Paleozoic Era when plants and animals were diversifying as they started to make their way from water to land.

Much of evolution is experimental, with success often measured by a species’ versatility, or ability to adapt to many different places and conditions. The peculiar set of tree fossils presents proof of a “failed experiment of science and evolution,” Stimson added. “We’re really starting to paint that picture as to what life was like 350 million years ago.”

Researchers excavated the first Sanfordiacaulis fossil tree about seven years ago, but four more specimens were found in close proximity to one another few years later.

Looking forward

Fossils such as the Sanfordiacaulis are not just useful in helping humans understand how life changed in the past, they can help scientists figure out where life on our planet might be headed next.

The existence of this particular species suggests that trees of the period were starting to occupy different ecological niches beyond what was previously understood, according to the researchers behind its discovery.

Gastaldo sees this as an indication that plants — much like early invertebrates — were experimenting with how they adapted to the environment. The earthquake that likely led to the trees’ fossilization also offers new geological evidence of what may have been occurring in Earth’s systems at the same moment in time.

“This is really the first evidence we have of (a tree) that would be between what grows on the ground and what would tower way above the ground,” Gastaldo said. “What else was there?”

Research finds evergreens with smaller leaves offer better air pollution mitigation

January 19, 2024 · 2 minute read
Research finds evergreens with smaller leaves offer better air pollution mitigation
Graphical abstract. Credit: Science of The Total Environment (2023). DOI: 10.1016/j.scitotenv.2023.169713

If you’re trying to take pollution out of the air, choose evergreen trees with smaller leaves. That’s according to a new study from the University of Surrey.

Researchers from Surrey’s Global Center for Clean Air Research (GCARE) tested 10 trees beside a busy main road. They studied which caught the most particles of  and which best allowed the rain to wash those particles safely to the ground.

The paper, which helps promote the UN Sustainability Goals 3, 11, 13 and 15, is published in the journal Science of the Total Environment.

It had been thought that leaves with rougher surfaces and minute hairs would catch more pollutants. Yet that wasn’t borne out by the evidence.

Yendle Barwise, former forester and University of Surrey researcher, said, “When tackling air pollution, the ideal leaves cling on to particles when it’s windy—but let go of them in the rain. That means the wind blows less pollution back into the air—but rain can wash it safely to the ground.

“Being rough and hairy isn’t all it’s cracked up to be. To remove more particle pollutants over time, leaves need to be washed by rainfall, and it seems that the size and shape of the  is much more important from this perspective.”

Many planting projects use , which lose their leaves in winter—even though that’s when air pollution is worst in towns and cities. For that reason, scientists chose ten evergreen specimens and placed them in plant pots beside the A3 in Guildford. Some 80,000 vehicles drive past every day.

Of those studied, Yew (taxus baccata) was the plant which removed most air pollution. The most effective leaf types were awl-shaped. They were found on Japanese cedar (camellia japonica) and Lawson’s Cypress (chamaecyparis lawsoniana).

The study also suggested that stomata—the ‘pores’ of the leaf—could help plants ‘catch’ particles. For Yew, more particles of pollution gathered on the porous underside of the leaf. That’s despite the other side of the leaf being 47% rougher, and despite previous research suggesting roughness mattered more.

Professor Prashant Kumar, founder of the University of Surrey’s Global Center for Clean Air Research, said, “We know that planting trees by roadsides can make a big difference to air quality. Our study shows that by choosing your trees carefully, that difference can be even bigger.”

“We’ve shown that smarter choice of plants can take even more pollution out of the air. We just studied the shapes and textures of the leaves themselves. Other factors, like the tree’s height, leaf chemistry, or how many trees you plant, could also make a big difference. Those are well worth investigating in the future.”

More information: Yendle Barwise et al, A trait-based investigation into evergreen woody plants for traffic-related air pollution mitigation over time, Science of The Total Environment (2023). DOI: 10.1016/j.scitotenv.2023.169713

Journal information: Science of the Total Environment

Provided by University of Surrey

Novel methodology projects growth of native trees, enhancing return on investment in forest restoration

January 19, 2024 · 5 minute read
Novel methodology projects growth of native trees, enhancing return on investment in forest restoration
The researchers developed a model that projects the time taken for trees native to the Atlantic Rainforest to reach the ideal size to be harvested for the timber industry. Credit: Pedro Brancalion/LASTROP-USPM

Interest in forest restoration has increased in recent years, both on the part of companies and financial markets and in academia and government. This is particularly the case in Brazil, whose government has pledged since the 2015 Paris Agreement to restore 12 million hectares of native forest. However, tree planting is costly, while data on species growth and other aspects of reforestation is scant.

A study published in the journal Perspectives in Ecology and Conservation helps fill the gap by showing how the production of timber from  can make restoration financially viable. The article proposes native species growth models, defines harvest times, and outlines an optimized scenario for timber production in biodiverse restoration plantations, reducing pressure on natural biomes like the Amazon.

The authors conclude that to achieve ; the forest restoration value chain must be driven by management and harvesting plans based on species-specific criteria relating to models of tree growth, combinations of native species, silvicultural treatments, and research and innovation.

Led by forest engineer Pedro Medrado Krainovic, the researchers developed a model that projects growth time for species native to the Atlantic Rainforest until they reach the ideal harvesting age.

Commercially viable growth rates are usually based on the time taken for trees to reach 35 cm in diameter at breast height (DBH). The novel methodology developed by the researchers reduced mean time to harvest by 25%, bringing the ideal harvest age forward by about 13 years, and increased mean basal area (stand density) by 38%.

“We calculated patterns of productivity versus time to obtain timber for the market, using parameters for management of each native species. This can assure the feasibility of large-scale forest restoration, making it attractive to landowners while also helping to meet the targets set by global climate agreements.”

“Based on our data, we projected a scenario for the improvement of silviculture to develop a restoration strategy that is worthwhile to the multiple stakeholders involved,” Krainovic explained. He participated in the study while he was a postdoctoral fellow in the Tropical Silviculture Laboratory at the University of São Paulo’s Luiz de Queiroz College of Agriculture (ESALQ-USP) in Piracicaba, São Paulo state, Brazil.

Although the Trinational Atlantic Forest Pact—a coalition involving Brazil, Argentina and Paraguay—has been considered a World Restoration Flagship and one of the “top ten pioneering initiatives that are restoring the natural world” by the United Nations, the Atlantic Rainforest has lost more forest area than any other Brazilian biome. Its vegetation originally covered in Brazil an area of 140 million hectares, of which only 24% are left. The SOS Mata Atlântica Foundation estimates that about half of this area still corresponds to well-conserved forest.

Efforts to stop deforestation and degradation have achieved positive results, with a 42% reduction year over year in January-May 2023 (from 12,166 ha to 7,088 ha deforested), and restoration projects are moving ahead robustly.

The United Nations Decade on Ecosystem Restoration, which runs from 2021 to 2030, is a global movement coordinated by both the UN’s Environment Program and the Food and Agriculture Organization to prevent and reverse the degradation of natural spaces across the planet for the benefit of people and nature.

“Restoration needs more data to point to favorable land-use horizons. Public policy requires more information to support decision-making. This article serves these purposes in several ways, including a list of species that can be profitable for landowners. It opens the door to the economic enrichment of forest restoration by making initiatives in this area more attractive and capable of achieving multiple purposes, such as the reinstatement of ecosystem services in specific areas,” Krainovic said.

The results of the study will be used by Refloresta-SP, a program coordinated by the São Paulo State Department of Environment, Infrastructure, and Logistics to restore degraded ecosystems and areas, develop multifunctional forests and implement agroforestry systems.

Krainovic lived in the Amazon for 12 years, working on forest restoration projects in degraded areas that use tree species with economic potential and on non-timber forest products for the cosmetics industry, such as seeds, essential oils, and butter. “I’m not your typical academic. I’ve been around. I know what business wants and how to interface with traditional communities in these value chains. I also know the science,” he said.

Methods and results

In the study, the researchers analyzed 13  restoration sites in different parts of São Paulo state, with varying mixtures of native tree species (30 to 100 species) and different ages (six to 96 years since planting). They formed a chronosequence that represented the potential growth performance of ten targeted timber species and the ecosystem services typically found in spontaneous forests. A chronosequence is a set of sites that are similar in soil types and environmental conditions but differ in age. The sites are replicated in space to replace replication in time.

The ten species were selected for having different wood densities and for having been historically overharvested for timber production. They were Balfourodendron riedelianum, Cariniana legalis, Cedrela fissilis, Centrolobium tomentosum, Esenbeckia leiocarpa, Hymenaea courbaril, Peltophorum dubium, Handroanthus impetiginosus, Astronium graveolens, and Myroxylon peruiferum. Most are protected by law and can no longer be legally sold, as they are endemic to the Atlantic Rainforest and Cerrado (savanna-like biome) and are officially classified as endangered. However, some (e.g., Hymenea courbaril and Handroanthus impetiginosus) are still harvested in the Amazon.

For each species, the researchers developed growth models based on data collected from the sites and used the method known as growth-oriented logging (GOL) to determine targeted management criteria, including an optimized timber production scenario based on growth and bole quality assessment.

After initial tests, they modeled DBH growth and basal area for selected species and constructed productivity scenarios using the 30% highest DBH values found for each species per site and age. The use of silviculture management techniques to boost productivity was assumed in the optimized scenario.

The species were classified on the basis of the time required to reach the ideal size for harvesting (DBH of 35 cm) as fast (under 50 years), intermediate (50-70 years), and slow (over 70 years). When the GOL approach was used, they were grouped into four growth classes: fast (under 25 years), intermediate (25-50), slow (50-75), and super-slow (75-100).

In the optimized scenario, the mean time to harvest decreased by 25%, and the mean basal area increased by 38%, for a reduction of 13 years in the ideal harvest age and a 48% increase in basal area (295 cm² per tree).

C. legalis and H. courbaril were exceptions: the ideal time to harvest was longer, but the basal area increased by over 50%. In the case of C. fossils, however, the basal area fell by 36% (646.6 cm² per tree), but the time to harvest decreased by 47 years (51% faster than the GOL measure).

Nine of the ten  reached a DBH of 35 cm in under 60 years. The exception was E. leiocarpia, albeit with high wood density.

More information: Pedro Medrado Krainovic et al, Potential native timber production in tropical forest restoration plantations, Perspectives in Ecology and Conservation (2023). DOI: 10.1016/j.pecon.2023.10.002

Provided by FAPESP

Declining primate numbers are threatening Brazil’s Atlantic forest

January 12, 2024 · 3 minute read
Declining primate numbers are threatening Brazil’s Atlantic forest
Credit: CC0 Public Domain

We tend to think of debt as purely financial, but we can also reap what we sow in the natural world through what is known as extinction debt. This concept refers to changes in the past that affect a species’ survival in the future.

Ecosystems often undergo profound and dramatic changes, but their effects are not always obvious to the naked eye. These changes are increasingly caused or triggered by humans.

In many cases, affected  may not actually disappear for several decades or even centuries: individuals survive, but under ecological conditions that do not allow them to maintain genetically viable populations. This often occurs with plant and  that have long life cycles, such as certain .

Some redwood or yew populations may therefore survive with the bare ecological minimum for long periods of time, but this does not mean that their existence is assured in the long-term future. This delayed result is the “debt” of extinction.

Such situations can occur in any ecosystem in the world, including tropical and subtropical forests. In fact, several studies have shown that biodiversity loss is accelerating on different continents, with the risk of mass extinction of species.

The primates of the Atlantic Forest

When we picture Brazil, it calls to mind the thriving Amazon rainforest, the mighty rivers of its vast basin and countless miles teeming with all manner of flora and fauna.

However, Brazil also hosts other landscapes which are just as unique as the Amazon. The CerradoCaatinga and the Mata Atlântica are just a few examples.

The Atlantic forests of South America—known as the Mata Atlântica in Brazil—are some of the richest and most diverse bioclimatic areas in the world, and are home to a large number of primate species. Many of these species are native to these forests and are in serious danger of extinction. This is the case, for example, for the southern muriqui (Brachyteles arachnoides) and the northern muriqui (Brachyteles hypoxanthus), two of the largest tree-dwelling species of New World monkey.

Smaller endemic primate species such as tamarins (Leontopithecus rosalia, L. chrysopygus, L. chrysomelas and L. caissara) are also in danger of extinction. Others, such as guaribas, also known as brown howler monkeys (Alouatta guariba), which were relatively abundant until a few years ago, have been decimated by the recent outbreaks of yellow fever that have affected eastern and southern Brazil. All the primate species of the Atlantic Forest have in common the fact that they survive in isolated forest fragments of varied dimensions, surrounded by crops and pastures.

Consequences for trees

Many of the interactions that occur between animals that feed on fruits and the plants that produce them are considered “mutualistic interactions”, a type of ecological relationship that benefits individuals belonging to two or more species. In these cases, the plants produce the fleshy, nutritious pulp of the fruits that is consumed by the animals. In return, many of their seeds are distributed in places where new plants can germinate and grow.

Human impacts often affect the interactions between animals—such as tree-dwelling primates—and plants. Recently, it has been found that these impacts often result in extinction debts affecting numerous tree species.

Trees that produce seeds that are large or protected by a very tough shell rely heavily on such animals to disperse their seeds effectively through the forest. Therefore, when large primates and other herbivorous vertebrates become locally, regionally or globally extinct, the plants whose seeds they disperse are also affected.

recent study attests to this. The research shows how deforestation,  and disease have affected the primates of the Atlantic Forest in southeastern and southern Brazil, and how the ecological interactions in which they participate or used to participate have changed.

This study warns that the progressive deterioration of the interlinking mutualistic interactions between animals and the plants on which they feed is jeopardizing the very survival of these forests.

This threat comes on top of climate change which will, in the short term, cause forest fires to become more frequent. In the middle and long term, it will turn vast areas of forest into open savannahs little suited to the needs of tree-dwelling primates. Forest fragmentation—whereby  areas are isolated from each other and surrounded by intensive sugar cane or soybean cultivation—will only exacerbate these effects.

Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Scientists name the most common tropical tree species for the first time

January 12, 2024 · 4 minute read
Scientists name the most common tropical tree species for the first time
Credit: Unsplash/CC0 Public Domain

A major international collaboration of 356 scientists led by UCL researchers has found almost identical patterns of tree diversity across the world’s tropical forests.

The study of over one million trees across 1,568 locations, published in Nature, found that just 2.2% of tree  make up 50% of the total number of trees in  across Africa, the Amazon, and Southeast Asia. Each continent consists of the same proportion of a few  and many rare species.

While tropical forests are famous for their diversity, this is the first time that scientists have studied the commonest trees in the world’s tropical forests.

The scientists estimate that just 1,053 species account for half of the planet’s 800 billion tropical forest trees. The other half is comprised of 46,000 tree species. The number of rare species is extreme, with the rarest 39,500 species accounting for just 10% of trees.

Lead author Dr. Declan Cooper (UCL Geography and UCL Center for Biodiversity and Environment Research) said, “Our findings have profound implications for understanding tropical forests. If we focus on understanding the commonest tree species, we can probably predict how the whole forest will respond to today’s rapid environmental changes. This is especially important because tropical forests contain a tremendous amount of stored carbon, and are a globally important carbon sink.”

He continued, “Identifying the prevalence of the most common species gives scientists a new way of looking at tropical forests. Tracking these common species may provide a new way to characterize these forests and in the future possibly gauge a forest’s health more easily.”

The researchers found strikingly similar patterns in the proportion of tree species that are common, at close to 2.2%, despite the tropical forests of the Amazon, Africa and Southeast Asia each having a unique history and differing contemporary environments.

The Amazon consists of a large region of connected forest, while Southeast Asia is a region of mostly disconnected islands. People only arrived in the Amazon around 20,000 years ago, but people have been living in African and Southeast Asian forests for more than twice that length of time. In terms of the contemporary environment, African forests experience a drier and cooler climate than the other two tropical forest regions.

Given these striking differences, the near-identical patterns of tree diversity suggest that a fundamental mechanism may govern the assembly of tree communities across all the world’s tropical forests. The researchers are not yet able to say what that mechanism might be and it will focus future work on identifying it.

The estimates of common species derive from statistical analyses, which do not provide the names of the common trees. To overcome this, the scientists used a technique known as resampling to estimate which are the most likely names of the common species.

Their list of 1,119 tree species names, the first list of common species of the world’s tropical forests, will allow researchers to focus their efforts on understanding the ecology of these species, which in turn can give scientists a shortcut to understanding the whole forest.

Scientists name the commonest tropical tree species for the first time
Most common tropical forest tree species. Credit: University College London

Senior author, Professor Simon Lewis (UCL Geography and University of Leeds) said, “We wanted to look at tropical forests in a new way. Focusing on a few hundred common tree species on each continent, rather than the many thousands of species that we know almost nothing about, can open new ways to understand these precious forests.”

“This focus on the commonest species should not take away from the importance of . Rare species need special attention to protect them, but quick and important gains in knowledge will come from a scientific focus on the commonest tree species.”

The researchers assembled forest inventory data from intact tropical forests that hadn’t been affected by logging or fire. In each of the 1,568 locations, teams identified and recorded every tree with a trunk greater than 10 centimeters in diameter, in a patch of forest, usually one hectare, which is a square of forest measuring 100 meters on each side.

Professor Lewis has been collecting and collating this data for 20 years. The effort is a collaboration of the largest plot networks across the Amazon (Amazon Tree Diversity Network; RAINFOR), Africa (African Tropical Rainforest Observatory Network, AfriTRON; Central African Plot Network), and Southeast Asia (Slik Diversity Network; T-FORCES), brought together for the first time for the published analysis.

This collaboration across hundreds of researchers, field assistants, and local communities resulted in a total of 1,003,805 trees sampled, which included 8,493 , across 2,048 hectares, equivalent to almost eight square miles of . The teams inventoried 1,097 plots in the Amazon totaling 1,434 hectares, 368 plots in Africa totaling 450 hectares, and 103 plots in Southeast Asia totaling 164 hectares.

More information: Declan Cooper, Consistent patterns of common species across tropical tree communities, Nature (2024). DOI: 10.1038/

Journal information: Nature

As tree species face decline, ‘assisted migration’ gains popularity in Pacific Northwest

January 5, 2024 · 6 minute read
As tree species face decline, ‘assisted migration’ gains popularity in Pacific Northwest

As native trees in the Pacific Northwest die off due to climate changes, the U.S. Forest Service, Portland, Oregon and citizen groups around Puget Sound are turning to a deceptively simple climate adaptation strategy called “assisted migration.”

As the world’s climate warms, tree growing ranges in the Northern Hemisphere are predicted to move farther north and higher in elevation.

Trees, of course, can’t get up and walk to their new climatic homes. This is where assisted migration is supposed to lend a hand.

A section of a Douglas fir tree with the bark removed by scientists to examine insect damage that led to the tree's death following heat stress in the Willamette National Forest, Ore., Friday, Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Amanda Loman)
A section of a Douglas fir tree with the bark removed by scientists to examine insect damage that led to the tree’s death following heat stress in the Willamette National Forest, Ore., Friday, Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Amanda Loman)

The idea is that humans can help trees keep up with climate change by moving them to more favorable ecosystems faster than the trees could migrate on their own.

Yet not everyone agrees on what type of assisted migration the region needs — or that it’s always a good thing.

In the Pacific Northwest, a divide has emerged between groups advocating for assisted migration that would help struggling native trees, and one that could instead see native species replaced on the landscape by trees from the south, including coast redwoods and giant sequoias.

“There is a huge difference between assisted population migration and assisted species migration,” said Michael Case, forest ecologist at the Virginia-based Nature Conservancy.

Case currently runs an assisted population migration experiment at the Conservancy’s Ellsworth Creek Preserve in western Washington.

Assisted population migration involves moving a native species’ seeds, and by extension its genes, within its current growing range.

By contrast, assisted species migration involves moving a species well outside its existing range, such as introducing redwoods and sequoias to Washington.

A third form of assisted migration, called “range expansion,” amounts to moving a species just beyond its current growing range.

Case’s project involves testing whether breeds of native Douglas fir and western hemlock from drier parts of the Pacific Northwest can be used to help western Washington forests adapt to climate change. He says the Nature Conservancy is focusing on population migration because it has fewer ecological risks.

“Whenever you plant something in an area where it is not locally found you increase the risk of failure,” Case said. “You increase the risk of disturbing potential ecosystem functions and processes.”


Douglas fir trees that died as a result of insect damage following heat stress are visible in the Willamette National Forest, Ore., Friday, Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Amanda Loman)
Douglas fir trees that died as a result of insect damage following heat stress are visible in the Willamette National Forest, Ore., Friday, Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Amanda Loman)

Christine Buhl, forest health specialist for the Oregon Department of Forestry, holds a tree core from a dead Western Red Cedar, showing healthier rings toward the right of the sample and more drought-affected rings to the left, at Magness Memorial Tree Farm in Sherwood, Ore., Wednesday, Oct. 11, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Amanda Loman)
Christine Buhl, forest health specialist for the Oregon Department of Forestry, holds a tree core from a dead Western Red Cedar, showing healthier rings toward the right of the sample and more drought-affected rings to the left, at Magness Memorial Tree Farm in Sherwood, Ore., Wednesday, Oct. 11, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Amanda Loman)
A dead branch is visible on a Western Red Cedar tree in the Willamette National Forest, Ore., Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Amanda Loman)
A dead branch is visible on a Western Red Cedar tree in the Willamette National Forest, Ore., Oct. 27, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Amanda Loman)

EDITOR’S NOTE: This story is part of a collaboration between The Associated Press and Columbia Insight, exploring the impact of climate on trees in the Pacific Northwest.


Population migration is the only form of assisted migration currently practiced nationwide by the Forest Service, according to Dr. David Lytle, the agency’s deputy chief for research and development.

“We are very, very cautious and do not engage in the long-distance movement and establishment of plant material outside and disjunct from the historic range of a species,” said Lytle.

The Forest Service is pursing assisted population migration because it’s likely to have few if any “negative consequences” to ecosystems, he said.

Douglas Tallamy, professor of entomology and wildlife ecology at the University of Delaware, said one potential negative consequence of species migration is the possibility that native caterpillars might not eat the leaves of migrated nonnative tree species. Because caterpillars feed birds and other animals, this could lead to disruptions to the food web.

This could happen if the City of Portland migrates oak species from places to the south, Tallamy noted. “Oaks are the most important plant for supporting wildlife that we have in North America,” he said, “but when you move them out of range, the things that are adapted to eating them no longer have access to them.”

FILE - City of Bellevue Forest Management Program Supervisor Rick Bailey holds a juvenile giant sequoia in his hands on Oct. 11, 2022, in Bellevue, Wash. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Manuel Valdes, File)
FILE – City of Bellevue Forest Management Program Supervisor Rick Bailey holds a juvenile giant sequoia in his hands on Oct. 11, 2022, in Bellevue, Wash. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Manuel Valdes, File)

The City of Portland’s Urban Forestry program is currently experimenting with the assisted migration of 11 tree species, including three oak species to the south: California black oak, canyon live oak and interior live oak.

Asked via email about potential ecological disruptions Portland’s City Forester & Urban Forestry Manager Jenn Cairo responded: “We use research from universities, state and federal sources, and local and regional field practitioner experience.”

Another advocate for species migration is the Puget Sound-based, citizen-led PropagationNation. The organization has planted trees in several parks in the Seattle area and has the ambitious goal of “bringing a million coast redwoods and giant sequoias to the Northwest,” according to its website.

The PropagationNation website also recommends planting redwoods in areas where native western red cedar, western hemlock, Sitka spruce and big leaf maple already grow.

Western red cedar, western hemlock and big leaf maple have all seen die-offs and growth declines in recent years tied to climate.

Philip Stielstra, PropagationNation’s founder and president, and a retired Boeing employee, declined to comment for this story.

David Milarch, founder of the Michigan-based Archangel Ancient Tree Archive, which has supplied PropagationNation with redwoods and sequoias, says his trees aren’t intended to replace Pacific Northwest native species.

“All we are doing is extending the range (of redwoods and sequoias) north in the hopes that they will still be here in 100 to 200 years and not join the list of trees that are going extinct,” said Milarch.

Robert Slesak, research forester at the Pacific Northwest Research Station, runs the Forest Service’s Experimental Network for Assisted Migration and Establishment Silviculture, or ENAMES project, which oversees population migration sites in Washington, Oregon and California.

Slesak called moving redwoods north a “risky proposition.” He said he has serious concerns about both assisted species migration and assisted migration efforts that lack experimental rigor.

“Widespread assisted species migration without a lot of experimental results to guide it is risky,” said Slesak. “Everyone knows we need to do some kind of action related to climate, but there’s a real risk of making it worse.”

Nevertheless, with the effects of climate change increasing, it’s a risk increasingly being assumed by public and private groups around the Pacific Northwest.

Moss grows on the branches of a dead western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Wednesday, Oct. 11, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Amanda Loman)
Moss grows on the branches of a dead western red cedar at Magness Memorial Tree Farm in Sherwood, Ore., Wednesday, Oct. 11, 2023. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Amanda Loman)

FILE - City of Bellevue Forest Management Program Supervisor Rick Bailey stands among dozens of juvenile giant sequoias Oct. 11, 2022, in Bellevue, Wash. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called "assisted migration." (AP Photo/Manuel Valdes, File)
FILE – City of Bellevue Forest Management Program Supervisor Rick Bailey stands among dozens of juvenile giant sequoias Oct. 11, 2022, in Bellevue, Wash. As native trees in the Pacific Northwest die off due to climate change, the U.S. Forest Service and others are turning to a strategy called “assisted migration.” (AP Photo/Manuel Valdes, File)


Nathan Gilles is a science writer and journalist based in Vancouver, Washington.


Columbia Insight is an Oregon-based nonprofit news website covering environmental issues affecting the Pacific Northwest.

Country diary: Time has turned this tree trunk soft as trifle sponge

January 5, 2024 · 2 minute read
Country diary: Time has turned this tree trunk soft as trifle sponge
The stump of the ash tree in midwinter. Photograph: Sara Hudston

Horner Woods, Somerset: During the holidays I went in search of an old acquaintance by the side of a tumbling river

Three years ago, in May, when the wood rang with birdsong, I photographed an old ash tree growing at the side of Horner Water. It was a stump with two broken forks, but its moss-furred trunk was firm and thickly rooted, drawing the earth to it. New branches, the width of a child’s arm, sprouted from the bole and waved green fingers.

I sought it out again during the Christmas holidays, when the wood was greyed by midwinter and the only sound was the regular muffled bump of a boulder rocking deep in the tumbling stream.

May ash: The ash tree stump on May 2021.
The ash tree stump in May 2021. Photograph: Sara Hudston

At first, I couldn’t find it. There was the ivied oak, the low scramble of blackberry, the understory of hawthorn and hazel stripped bare of the spring gauze I remembered. Surely the ash couldn’t be that modest dead tree at the side of the clearing? It seemed so diminished, ebbing out of itself into the soil.

A good third of the trunk had collapsed on the ground where it lay, soft-soaked as trifle sponge. Minute orange blobs of pin-head fungi glowed against the blackened bark like a sprinkling of sherbet pips. The tree was riven where the years had passed through.

Inside ash: The hollow inside of the split ash tree, rippled like hair or water.
The hollow inside of the split ash tree, rippled like hair or water. Photograph: Sara Hudston

The fall had exposed its hollow trunk, which was rippled inside like hair, or like the water that grunted and chuckled a couple of metres away. The newer branches were dead too, their vigour choked by decay below.

I walked away, kicking up coracles of wet leaves. Something bright caught my eye: a fat bead the colour of apricot jam welded to a leaf. It was an oak marble gall, formed by larvae of the Andricus kollari wasp, a Mediterranean species. These insects were introduced to the UK in the 19th century because their galls have a particularly high tannin content, helpful in the process of tanning leather.

The gall was a reminder that these woods, now so tranquil, were once an industrial workplace. They produced bark for leather-making and charcoal for smelting the iron ore that was mined in the pits nearby. The noise of the hammer mill would have echoed down the combe along with the voices of dozens of people who lived here.


Fourth Annual Restore the Wild Artwork Competition and Exhibition Open

December 27, 2023 · 2 minute read
Fourth Annual Restore the Wild Artwork Competition and Exhibition Open

The spotted skunk’s unique stance. Photo by Agnieszka Bacal/Shutterstock

By Molly Kirk/DWR

Calling all artists! After a resounding success last year, the Restore the Wild Artwork Competition is returning to the Virginia Department of Wildlife Resources (DWR) and calling for artists to submit artwork supporting Restore the Wild’s mission of creating and maintaining habitat to help Virginia’s wildlife thrive. Entries in the contest will be displayed in an exhibition, and winning Restore the Wild Artwork Competition is used to help promote Restore the Wild’s mission.

Last year, more than 100 artists took on the unusual challenge of depicting the Eastern hellbender, an aquatic salamander nicknamed the “snot otter.” This year, we’re trading slime for fur and asking artists to submit art featuring the Eastern spotted skunk (Spilogale putorius). Not to be confused with the common striped skunk ubiquitous to back yards throughout the state, the spotted skunk is a Species of Greatest Conservation Need in Virginia and found in the foothills of the Blue Ridge Mountains and further west. This species is known for its unique handstand warning posture before it sprays.

Pieces selected for the 2024 Restore the Wild Artwork exhibition will be displayed in the Pine Camp Cultural Arts and Community Center in Richmond from Friday, March 8 until Friday, March 29. On Friday, March 8, there will be a public opening reception, 6:00 p.m. – 8:00 p.m. Thereafter, the exhibition will be open to the public daily, Monday – Friday, 9 a.m. to 4:00 p.m.

Artists are invited to submit in the categories of Natural History Illustration, Artistic Expression, Youth 10 & Under, and Youth 11-16. See more details about submissions in the Restore the Wild Artwork Competition Rules and Guidelines. Please note that photography submissions are not allowed.

Virginia has more than 900 species of wildlife whose numbers are in decline mostly because of impacts to their habitat—natural areas that provide necessary food, water, and shelter. DWR is the lead agency in Virginia for the conservation of wildlife and wildlife habitat. DWR’s Restore the Wild initiative allows DWR to expand the work the agency does to preserve, establish, and maintain vital wildlife habitat areas and keep Virginia’s wild places wild. Memberships and donations to Restore the Wild provide funds directly for DWR habitat projects.

Restore the Wild’s Artwork Competition calls for submissions from the public (excluding photography) that reflect Restore the Wild’s mission to restore and create natural habitats vital to the survival of Virginia’s wildlife. Contest judges will evaluate the works not only on their artistic merit, but also on their precision in illustrating the species’ physical characteristics and habitat. Make sure to visit the Artwork Competition Rules and Guidelines for complete details.

I discovered … a tiny 700-year-old forest within sight of North America’s busiest highway

December 27, 2023 · 4 minute read
I discovered … a tiny 700-year-old forest within sight of North America’s busiest highway
‘Trees taught me growth is not necessarily good’: Doug Larson near his home in Guelph, Ontario. Photograph: Cole Burston/The Guardian

I realized other ancient trees could have survived, right under our noses. In France, they discovered one tree that had started growing before the Romans left.

I’ll be 75 in March, and we old people often reflect on why certain things happened in our lives. This is very personal, but I was tall and skinny as a kid – I was always the one who was beaten up at school. The only refuge I had was in plants and bugs, and animals in general.

Nothing in nature ever tried to “get me” – even predators. They weren’t after me. I always felt a sympathy with critters that were under attack or vulnerable. Your personality guides your research, and this got me interested in the idea of “harshness” in environments.

This would eventually lead me to become a professor of biology at the University of Guelph, and to discover the most ancient and least-disturbed forests in eastern North America – perhaps even the oldest in North America.

Doug Larson sits on a sofa in a comfortable room at home in Guelph, Ontario.
Doug Larson at home in Guelph, Ontario. Photograph: Cole Burston/The Guardian

I didn’t begin by looking at trees. The organisms I first worked on were the most marginalised and misunderstood plants in the world: lichens. Many live in Arctic tundra where the wind, snow and cold attack vegetation all the time, making things tiny and stunted. And yet, they are surviving in their own little paradise because no one else bothers them.

When I got my PhD, I decided to work in a habitat that would be as brutal as the Arctic tundra, and that’s when the idea to work on the Niagara Escarpment kicked in. There were these stunted, groggy-looking organisms up there and no one had ever considered them worth studying. People called them “rock scum”. But from the point of view of someone who is sympathetic to critters getting beaten up, this was a beautiful habitat; I wanted to study it.

The people in my lab assumed Europeans had clear-cut all of southern Ontario, so we didn’t expect to find ancient trees anywhere. But then we found these tiny, ancient trees clinging on to a thin sliver of harsh habitat.

When we found our first tree that was more than 1,000 years old I thought, “you have got to be kidding”. I had goosebumps. It was like a lightning bolt hitting – it put this forest into a completely different category.

So many people had walked past this and just assumed there was nothing there. It’s within sight of the busiest highway in North America, the 401, and one of the largest cities, Toronto. It was a shock to find them in such an industrialised urban setting.

View from above of Doug Larson on a cliff holding a tree with a long drop behind him with a switchback road seen snaking round the mountain.
Doug with an ancient tree in Canada, 1997. He has also found old growth trees in France, the US, New Zealand, Germany and England. Photograph: Courtesy of Doug Larson

We began research to find out the limits of antiquity of the trees in this forest. One was more than 1,800 years old, although it had died a long time ago.

The next question was: is the presence of this ancient forest on these cliffs unique to Ontario? There are lots of beautiful limestone outcrops in the south of France so I contacted researchers in Montpellier and said we’d like to come and study them. Again, they told me there was “nothing there”. Yet they ended up finding one tree that had started to grow before the Romans left France. That made headlines in Le Figaro. This tree had watched the Romans leave! They are the oldest living plants in France.

We found there were ancient forests on all the cliffs in the south of France, and then we ended up making similar discoveries in the US, New Zealand, Germany and England. It turned out these tiny ancient forests are everywhere. Cliffs have now been recognised as one of the hotspots of biodiversity globally.

It was 1988 when the media first took an interest in the ancient forests. It’s now 2023, and it has never stopped. It links to the whole question of human life – when you work on something that’s 1,000 years old, suddenly you feel smaller and realise your role in the universe is not as grand as you’d thought.

Man on climbing ropes going up a cliff face with trees growing out of it.
Ancient forests growing on cliffs. Partly due to Doug Larson’s work, cliffs have now been recognised as biodiversity hotspots. Photograph: Courtesy of Doug Larson

We humans place great value on productivity. What I’ve learned philosophically about life from the ancient trees is peace and joy can be found in the slow, the cautious and the careful, as much as it can be in the rich and famous.

I have found the ancient forest to be my greatest teacher. The trees have taught me that growth is not necessarily essential or good. If we humans want to be sustained by this planet for ever, we cannot suck it dry. This ancient forest is one place that we haven’t got to – it has survived us by us ignoring it. There’s a way to make the planet infinitely sustainable for us, if we simply ask less of it.

  • As told to Phoebe Weston. Doug Larson is professor emeritus of biology at the University of Guelph in Ontario, Canada. He is an expert on deforestation and regularly contributes to media discussions on the topic of old growth forests. His latest book, written with his son Nick, is called The Dogma Ate My Homework

‘We’ve got to save that tree!’ Iconic pine on the Fairfax County Parkway gets new home

December 22, 2023 · 1 minute read
‘We’ve got to save that tree!’ Iconic pine on the Fairfax County Parkway gets new home

The tree that was once in the center median on Popes Head Road in Fairfax County has found a new home. (WTOP/Kyle Cooper)

A beloved tree in Fairfax County, Virginia, known to lift spirits around the holidays, has disappeared from its longtime location — but it’s found a new home.

The tree sat in the center median at the intersection of Popes Head Road of the Fairfax County Parkway — a full but misshapen pine with a Charlie Brown Christmas tree vibe. Every year at Christmastime random people would stop to decorate it.

Jimmy Sims would often drive by the tree when taking his 8- and 10-year-old daughters to school. They stopped and decorated it recently with silver and red tinsel. Sims said they were all surprised to see traffic cones around the tree this week.

“The kids were pretty sad. They thought it was going to get chopped down,” said Sims.

It turned out the tree had to be removed due to a major Virginia Department of Transportation project to improve that intersection.

Ellen Kamilakis, a spokesperson for VDOT, went to her boss and said, “We’ve got to save that tree.”

The tree was carefully removed, balled and put in burlap, and moved to VDOT’s property on Alliance Drive and West Ox Road.

“We can’t save every tree, but this one we could, so we did,” said Kamilakis.

In a video posted on X about moving the tree, Kamilakis, who donated some of her own money for supplies to replant the tree, said people can still stop by to visit the tree and even decorate it if they want to.

“I love that tree. It brings me joy every year when I see it decorated,” said Kamilakis.

As for the tree’s future, Kamilakis said if there is a good spot for the famous tree back at the intersection after the road project is complete, it might get moved back.

Trees are in trouble

December 21, 2023 · 3 minute read
Trees are in trouble
Photo Credit
Joan Dudney
The trees in this lush, temperate forest in the Cascade Range of Washington are likely less resistant to drought than their counterparts in drier regions to the south.

Scientists flip the script, revealing trees in wetter regions are more sensitive to drought

This holiday season brings surprising news about your Christmas tree. Scientists just discovered that globally, trees growing in wetter regions are more sensitive to drought. That means if your tree hails from a more humid clime, it’s likely been spoiled for generations.

Scientists have long debated whether arid conditions make trees more or less resilient to drought. It seems intuitive that trees living at their biological limits will be most vulnerable to climate change, since even just a little extra stress could tip them past the brink. On the other hand, these populations have adapted to a harsher setting, so they might be more capable of withstanding a drought.

According to a new study in the journal Science by researchers at UC Santa Barbara and UC Davis, greater water availability could “spoil” trees by reducing their adaptations to drought. “And that’s really critical to understand when we’re thinking about the global vulnerability of forest carbon stocks and forest health,” said ecologist Joan Dudney, an assistant professor at UCSB’s Bren School of Environmental Science & Management and in the Environmental Studies Program. “You don’t want to be a ‘spoiled’ tree when facing a major drought.”

Dudney and her co-authors expected trees growing in the most arid regions to be more sensitive to drought, since they’re already living at the edge of their limits. What’s more, climate change models predict that these regions will experience more rapid drying than wetter regions. This shift in climate could expose trees to conditions beyond their adaptive capacity.

To measure drought sensitivity, the authors analyzed 6.6 million tree ring samples from 122 species worldwide. For each year, they measured whether the tree grew faster or slower than average based on its ring width. They linked these trends with historic climate data, including precipitation and temperature.

The team then compared drought responses across different regions. “As you move to the drier edge of a species’ range, trees become less and less sensitive to drought,” said lead author Robert Heilmayr, an environmental economist also in the Environmental Studies Program and at the Bren School. “Those trees are actually quite resilient.”

Dudney, Heilmayr and their co-author Frances Moore were inspired, in part, by the work of UCSB professor Tamma Carleton on the effects climate change has on human populations. “This paper highlights the value of cross-disciplinary scientific work,” added Moore, an associate professor at UC Davis. “We were able to adapt methods from economics originally developed to study how people and businesses adjust to a changing climate and apply them to the ecological context to study forest sensitivity to drought.”

“A heatwave is likely to kill more people in a cool place like Seattle than in hotter cities like Phoenix,” Heilmayr said. The Southwest is already quite hot, so heatwaves there are scorching. But the region’s cities are adapted to an extreme climate, he points out. Now we know that forests display similar trends.

Unfortunately, warmer regions are slated to get disproportionately drier in the coming decades. “There is a pretty large portion of species’ ranges that are going to face a completely novel climate, something that those species don’t see anywhere in their range today,” Heilmayr explained. The authors found that 11% of an average species’ range in 2100 will be drier than the driest parts of their historic range. This increases to over 50% for some species.

“Broadly, our research highlights that very few forests will be unaffected by climate change,” Dudney said. “Even wetter forests are more threatened than we thought.”

Mixed living and dead trees with mountains in the background.
Photo Credit
Joan Dudney
This mixed conifer forest in Sequoia National Park experienced high mortality following an extreme drought between 2012 and 2016.

But there is a flip side of the coin. Species have a reservoir of drought-hearty stock in the drier parts of their range that could bolster forests in wetter areas. Previous research out of UCSB revealed that many species do have the capacity to adapt to environmental change. However, those researchers also found that trees migrate slowly from one generation to the next. That means human intervention — such as assisted migration — may be necessary in order to take advantage of this genetic diversity.

Whether your Christmas trees grow in a dry or wet region, they’ll likely experience growth declines in the future. But understanding how trees will respond to climate change can help ensure the future of the Tannenbaum and its wild counterparts.


An aerial eye on the forest

December 7, 2023 · 4 minute read
An aerial eye on the forest

Gathering a deep understanding of a forest, from the roots to the treetops, was once only possible after months of walking the landscape.  But soon U.S. Department of Agriculture’s Forest Service employees could be using their thumbs and a mechanical friend to help get the job done in days.

Meet the Vision Aerial Switchblade. With a top speed of 62 mph and weighing in at just over 7 pounds, this uncrewed aerial system or UAS can fly over a landscape while gathering data on the terrain. It sees the big picture and the little picture — from the broad health of the forest, down to specifics on an individual tree — which informs land management decisions.

The Vision Aerial Switchblade can be fitted with a mirrorless camera. This camera takes a series of overlapping photos which can later be processed as a 3D image. (USDA Forest Service photo by Andrew Avitt

“We can use uncrewed aerial systems in many ways,” said Chris Brenzel, a UAS specialist with the Forest Service. “In this instance, we’re using it to map the vegetation to generate 3D models of the forest, which gives us specific data on the width and height of the trees, the health of the trees, canopy cover, and the size of the crowns. From that, we can determine which trees are dead, which trees are struggling, and which trees are healthy to better plan how to treat these areas.”

Brenzel is one of many UAS pilots assigned to survey a proposed project area of 58,000 acres on the Inyo National Forest surrounding Mammoth Lakes, California. It’s one of several projects that coincide with the Forest Service’s national strategy to confront the wildfire crisis, protect communities, and improve resilience in America’s forests. (Leer en español).

The Vision Aerial Switchblade can be fitted with a mirrorless camera. This camera takes a series of overlapping photos which can later be processed as a 3D image. (USDA Forest Service photo by Andrew Avitt

The Power of Data to Reduce Wildfire Risk and Support Forests

The Eastern Sierra Communities and Climate Resilience Project has two main objectives — to reduce wildfire risk to residents and to increase forest health and resilience.

Nathan Sill, an ecosystem services staff officer for the Inyo National Forest, coordinates the information gathering and planning for the project.

“We want to reduce wildfire risk to the town of Mammoth Lakes and associated infrastructure, as well as restore healthy forests and provide for long-term resilience. So, we are planning to reduce the density of fuels immediately around the town. Then, as we move away from that community, those treatments become more in line with forest resilience,” said Sill.

The Switchblade’s big brother the FVR-90, a fixed-wing drone has the capability of flying around the entire perimeter of a wildfire, updating maps and providing real time intelligence to firefighters. (USDA Forest Service photo by Andrew Avitt) 

The UAS data will enable ecosystem staff officers like Sill to identify overstocked areas of forests, where too many trees have made stands susceptible to drought, disease and wildfire.

That data helps determine which land management treatments are needed to remove vegetation, such as mechanical thinning or prescribed fire.

An aerial view of the wildland urban interface near Mammoth lakes, California. (USDA Forest Service photo by Harry Oh

“This technology has the potential to provide much higher resolution data for us to use, and it also allows us to share that data visually with the public,” said Sill. “As this technology becomes more reliable, and we become more efficient with collecting the data and using it, this will be a game changer for forest management.”

An Efficient, Safer Perspective

The efficiency and the safety benefits of this emerging technology can’t be overstated.

“It would take months and many, many people going out to survey the same areas that these drones have flown in a few weeks,” said Brenzel. “In the future, we could fly 150 to 200 acres a week and get that mapped and modelled. That’s a force multiplier and frees people up to do other projects and actually implement them.”

From a safety perspective, UAS enables employees to observe, from a distance, dangerous areas such as steep terrain or locations with standing dead trees, known as snag patches.

 Chris Brenzel, UAS specialist, keeps a watchful eye on his aircraft as it carries out an automated flight plan collecting data on the surrounding forest. Right: A thumb controls an uncrewed aerial system over the Inyo National Forest near Mammoth Lakes, California. (USDA Forest Service photos by Andrew Avitt) 

“There are a lot of snag patches around here from beetle kill and drought,” said Brenzel. “In the past, we’ve had firefighters and other employees killed and injured by trees. [With UAS] we’re not putting our employees in danger just to survey these areas.”

The Forest Service continues to explore even more uses for UAS. Their data is assisting with forest health projects, prescribed fire, wildlife surveys and wildfire suppression.

Brenzel has worked in federal land management for nearly 30 years, from the Bureau of Land Management and the National Park Service to the Forest Service. He’s seen the adoption of UAS expand exponentially.

“We’re really finding a lot of cases where we can mitigate the risk to our employees and pilots and still meet the mission,” said Brenzel. “We’ve seen 300% growth in the three years basically since the program was stood up, but it takes time. We have to train employees; we have to get equipment. But it’s increasing. Because if we can get that data, we can keep our people safe and we can do our jobs better.”

Two forest service employees stand next to a drone on an orange landing pad
Firefighters use a UAS to support the Antelope Prescribed Burn on the Mammoth Ranger District, Inyo National Forest June 2023. (USDA Forest Service photo by Lisa Cox

More pictures and video of the Forest Service using aerial systems at Uncrewed Aerial Systems of the Forest | Flickr 

Real or artificial? A forestry scientist explains how to choose the most sustainable Christmas tree, no matter what it’s made of

December 7, 2023 · 5 minute read
Real or artificial? A forestry scientist explains how to choose the most sustainable Christmas tree, no matter what it’s made of

Every year, Americans buy somewhere between 35 million and 50 million Christmas trees, and many more pull an artificial tree out of storage for the season. In all, about three-quarters of U.S. households typically have some kind of Christmas tree, surveys show.

People often ask which is more sustainable – a real tree or an artificial one? It’s a big debate, and the answer depends on who you ask and which factors you consider.

A more useful question is: How do I find the most sustainable tree of the kind I want to get?

I’m a forestry professor who works on issues of sustainability. There are advantages and disadvantages to both cut trees and artificial trees. Here are some tips to consider for each.

Cut Christmas trees require water and maintenance – and careful thought about disposal. Photo by Any Lane

If you’re buying a live Christmas tree

When Christmas trees are alive and growing, they pull carbon dioxide from the air and use it as the building blocks of their wood. That keeps the greenhouse gas out of the atmosphere, where too much carbon dioxide contributes to global warming.

This process stops once the tree is harvested. And at some point, the cut tree begins to decompose and releases that carbon again.

Christmas tree farms like this one in Greencastle, Ind., can be found in almost every state. USDA

On the positive side, the tree’s root systems will continue to store carbon for some time, and new trees are typically planted to continue the cycle.

So, how do you find the most sustainable live tree?

Think about the tree’s origin

If you live in Mississippi, like I do, buying a noble fir (Abies procera) means your tree probably came from the Pacific Northwest. That’s a long drive, and transportation is a major source of greenhouse gas emissions. However, in a truck with several hundred trees, each individual tree’s transportation emissions are pretty minor.

A map of Douglas-fir locations, primarily in the Pacific Northwest and intermountain West
Douglas-firs grow primarily in the Western U.S. USDA

The most common Christmas tree varies by region: Douglas-fir is also common throughout the Mountain West. Scotch pine and balsam fir are regularly grown in the Great Lakes states. Fraser fir is also popular there but dominant in North Carolina. Leyland cypress and Virginia pine are common in the Southeast.

Maps showing balsam fir growing areas.
Balsam firs, also popular for Christmas trees, grow in the Great Lakes region, New England and Canada. USDA

There are many other wonderful species grown locally. Of course, the lowest-impact cut tree is the one you cut from your own yard.

Also, look for local nurseries that protect their soils from erosion and minimize harm to surface and groundwater from runoff that can include fertilizers or pesticides.

Disposing of your live tree

What you do with your tree after the holidays also matters.

Recycling is far better than leaving the wood to decompose in a landfill. Because of the nature of most landfills, anaerobic conditions will ultimately exist, and decomposition will result in the release of methane gas, which is many times more potent than carbon dioxide at warming the atmosphere.

Look for a community or retailer that offers to chip the tree or shred it to create mulch or for use in animal stalls. This keeps it out of landfills and serves a purpose.

Composting is another option. Trees can be used as an erosion barrier for sand or soil or as fish habitat in lakes. They can even be donated whole to zoos, where the trees provide entertainment for animals while eventually decaying outside of a landfill, or they can be tossed into a bio-burner to provide heating for buildings. Some people even feed trees to goats.

Alternatively, consider cutting the tree into smaller pieces and letting it rot in the open, placing it in an out-of-the-way place in your yard. It will provide a temporary home for many insects, birds and wildlife.

Artificial trees have different pros and cons

Artificial trees also have advantages – they can last for years and require almost no maintenance. However, they are mostly a petroleum-based product, and when you throw one out, it can take hundreds of years to decompose.

If you plan to buy an artificial Christmas tree – maybe you have allergies like I do, or you’re concerned about cost – here are some suggestions to reduce your carbon footprint.

Reuse, reuse, reuse

The No. 1 way to reduce emissions with an artificial tree is to reuse it for years. Reuse avoids the carbon impact of producing, packaging and shipping a new one. The break-even point – when your artificial tree’s emissions match the emissions of buying a live tree each year – varies from as little as four years to as many as 20 years, depending on the factors considered.

Many artificial trees are built to last 30 years or more. My family has had one for 25 years. To lengthen its life span, take care when putting it up and storing it. If the tree gets damaged, see if you can find replacement parts rather than replacing the entire tree.

Old artificial trees can be repurposed into garlands and other holiday crafts. Curtis VanderSchaafCC BY-ND

Pay attention to the source

About 80% of artificial Christmas trees are manufactured in China. Shipping is pretty efficient, but the tree still needs to get to and from the ports. You can also look for one manufactured nearby instead.

Some manufacturers are making trees out of recycled materials, at least in part, which helps reduce the tree’s carbon footprint. Shorter artificial trees, or designs with less foliage, also use less plastic.

The type of plastic used also affects the amount of petroleum used. Some research has suggested that plastic foliage made from polyethylene plastic molds may have a lower impact than traditional foliage made out of polyvinyl chloride, or PVC.

Give the fake tree a second life

If you no longer like your artificial tree – maybe it’s too big for a new home – try reselling the tree or donating it to a charity, thrift store or nursing home so that others can continue to use it.

You can also get creative and repurpose the old tree limbs into decorative wreaths, garlands or toy trees for a hobby train set.

Lighting also matters

With any holiday tree, be judicious about turning off lights when no one is around and at night. Consider using fewer lights. LED lights are more energy efficient than incandescent lights.

An elf ornament and Christmas light.
LED lights reduce energy demand. Barta IV via FlickrCC BY

In the grand scheme of the holidays, with people traveling and buying and returning gifts through the mail, the carbon footprint of your Christmas tree is a lesser concern. A round-trip flight from Los Angeles to Boston can produce more than 30 times the lifetime emissions of a typical artificial Christmas tree. Still, it’s fairly easy to make more sustainable choices and reduce your carbon footprint when you can.

3 Benefits of Genetically-Improved Christmas Trees

December 1, 2023 · 4 minute read
3 Benefits of Genetically-Improved Christmas Trees

Christmas trees are the centerpiece of the holiday season. But the fear of needles falling can deter shoppers from buying real trees from local growers.

That’s one of the reasons why the NC State Christmas Tree Genetics Program has spent more than four decades working to develop “elite” Fraser fir trees.

Fraser firs are native to North Carolina’s Appalachian mountains and represent more than 98% of all the Christmas tree species grown and sold in the state.

In the late 1990s, the Christmas Tree Genetics Program evaluated and tested tens of thousands of Fraser firs in an effort to identify those with the best genetic characteristics.

Researchers ultimately identified the best 25 from nearly 30,000 trees and then propagated and planted them on a six-acre seed orchard at the Upper Mountain Research Station in 2018.

The seed orchard contains more than 1,000 trees, some of which are already producing seed-bearing cones. A single cone can contain up to 100 seeds.

Researchers are collecting the cones for studies and will eventually submit them to a newly constructed seed processing facility in order to distribute the seeds to growers some time between 2026 and 2028.

“Our trees will make the lives of both growers and consumers easier,” said Justin Whitehill, director of the Christmas Tree Genetics Program.

The trees will not only have a superior growth rate and appearance, but they will also retain their needles longer after harvest. Check out the list below to learn more.

Growth Rate 

Fraser firs use cones to spread their seeds. As the cones dry out, they explode and the seeds are released. These seeds eventually sprout into the next generation of trees.

Every Fraser fir tree grows at a different rate, with some sprouting faster than others. But generally, they require at least 7-8 years in the field to reach the commercial height of 6-7 feet.

Many of the trees available on today’s market originated from older seed orchards, forests or abandoned tree farms, and don’t have improved genetics.

When comparing the growth of these trees to their genetically-improved counterparts over the course of seven years, Whitehill found that the genetically-improved trees reached an average height of around a foot taller.

“Our genetically-improved trees grew an extra 1-2 inches a year,” Whitehill said. “So instead of having to wait 7-8 years for a tree to reach the typical commercial height, growers might only have to wait 6-7 years.”

If growers plant the genetically-improved Fraser firs from the Upper Mountain Research Station by 2030, that means the trees could be available to consumers by 2036.


Fraser Fir is one of the most popular Christmas tree species in the United States, in part because of its symmetrical, conical shape.

The structure of a Fraser fir consists of a straight central stem with branches that turn slightly upward to form a symmetrical, conical shape with a narrow, pointed crown.

“If a grower can produce a tree like that, it’s great because that’s what customers want,” Whitehill said. “But there is a lot of work that goes into shaping trees.”

Between July and August, many growers shear Fraser firs to slow the growth rate of the trees. This ensures that the trees develop into the preferred shape.

The shape of Fraser fir is controlled at least in part by genetics, though researchers don’t know specifically which genes are responsible for it.

When the Christmas Tree Genetics Program identified the best 25 trees to propagate and plant at the Upper Mountain Research Station seed orchard, they considered the appearance of the trees as part of their selection criteria.

“Each of the trees selected for the orchard had a conical shape with dense branches, so we expect their offspring to grow that way as well,” Whitehill said.

He added, “If we can grow trees that already look like that and reduce or eliminate the need for manual labor, it’s going to save money for growers. It’s also going to make customers happy.”

Needle Retention 

Fraser firs have soft, dark green needles with silvery undersides.

Conifer trees tend to lose their needles at some point after they’ve been harvested due to the significant stress of being separated from their root system, according to Whitehill.

Experimentally, Whitehill said that most conifers experience the highest level of needle loss 40 days following harvest. Fraser firs, however, can hold onto their needles for several months — one of the key reasons why they’re so popular.

A Fraser fir’s ability to retain its needles after harvest is almost entirely controlled by its genetics, but it can also be affected by environmental conditions. When exposed to freezing temperatures, for example, a Fraser fir tree will retain upwards of 95% of its needles.

“In the mountains, if the weather is cooler and you get freezing temperatures, it shuts down the tree’s biological activities and slows down needle loss,” Whitehill said.

But with Christmas tree growers facing pressure to produce greenery earlier every year, they need trees that will retain their needles under warmer-than-average temperatures.

The Fraser firs developed by the Christmas Tree Genetics Program are expected to lose less than 1-2% of their needles, according to Whitehill, even in the absence of cooler temperatures.

“You might not even need to vacuum with the genetics developed by our program ,” Whitehill said.

Think You Found a Bear Den? Please Leave it Alone!

December 1, 2023 · 3 minute read
Think You Found a Bear Den? Please Leave it Alone!

A bear in her den.

By DWR Bear Team

As temperatures fall and food sources become less abundant, many bears in Virginia will enter a winter den. Other bears will greatly reduce their movements during but may remain active throughout the season. Movements and denning behavior vary greatly across regions of the state depending on weather and available food resources. With the abundant hard mast crop (acorns) across much of the state, many bears will likely delay den entry this year until few acorns can be found.

An image of a black bear making a winter den out of pine needles in a blackberry thicket

This bear chose a nice blackberry thicket and made a nest of pine needles for her winter den.

Black bears in Virginia will den in a variety of places including: brush piles, trees (cavities within tree), rock outcroppings, ground nests, debris piles, and occasionally under porches or unsecured crawl spaces. Not all black bears den for the full winter season. Often, black bears that enter a winter den are females who will birth their cubs in the den or females with yearlings. Male black bears may den, but generally do not stay in a den for the entire winter due to the lack of extreme cold weather and snow across much of Virginia.

An image of a hole in the ground covered by storm debris which contains a black bear den

While this pile of trees, limbs, and other debris leftover from a storm may not look too “homey,” it does the trick for a black bear and her cubs.

While many of us also slow down for the winter, there are still ample opportunities that take us afield in bear country. Whether enjoying a hike, cutting firewood, clearing brush, hunting, or doing other activities you may inadvertently stumble upon a black bear den. A female black bear, particularly one who has had cubs, will likely remain at the den unless they feel pressured to leave. Here are a few tips to avoid disturbing a bear den and what to do should a female leave her den.

Tips to avoid a den

  • Avoid hiking in dense brushy thickets or young cutover timber stands. If you must work in these areas be mindful of brush piles, gullies with debris piles, or storm damage areas with thickets of limbs/root balls.
  • Always maintain your dog on a leash to avoid a dog-bear encounter at a den site.
  • When burning a brush or debris pile on your property, look around the entire pile for signs of digging (fresh dirt, holes) or entry routes into the pile.
  • If you notice large excavated holes or fresh trails into debris or brush piles listen closely for the sound of cubs from a distance of at least 30ft away. They often emit a high pitched cry or “squall”.
  • To prevent a bear from denning under an occupied dwelling ensure that crawl spaces, mobile home underpinnings, and porches are closed and secured prior to December 1st each year.

Tips if you find a den

  • If you find a den on your property or while recreating do not disturb it or approach the area. Leave the area and if on public property alert an employee of the location.
  • If you inadvertently flush a female bear from a den, DO NOT approach the den. Take a GPS point of the location (or mark a nearby area with flagging) and leave the area immediately. If you have a dog with you, leash it and keep it maintained on a leash as you leave the area. Contact the Wildlife Helpline (1-855-571-9003) to report the den location.
  • Most often when left alone the female will return to the den, although they may not return until night. Do not go back to the den area as additional disturbance may cause the bear to leave again and not return.
An image of a black bear den within an unsecured crawl space

While not the ideal spot (according to the homeowner), bears can even make their winter den under porches or unsecured crawl spaces!

An image of a hollow tree; occasionally black bears will hibernate within them

Bears also sometimes choose a nice hollow spot in a tree to snooze through the winter.

The flat Fens of eastern England once held vast woodlands, study finds

November 25, 2023 · 5 minute read
The flat Fens of eastern England once held vast woodlands, study finds

Scientists from the University of Cambridge studied hundreds of tree trunks, dug up by Fenland farmers while plowing their fields. The team found that most of the ancient wood came from yew trees that populated the area between 4,000 and 5,000 years ago. Credit: Tatiana Bebchuk

The Fens of eastern England, a low-lying, extremely flat landscape dominated by agricultural fields, was once a vast woodland filled with huge yew trees, according to new research.

Scientists from the University of Cambridge studied hundreds of , dug up by Fenland farmers while plowing their fields. The team found that most of the ancient wood came from yew trees that populated the area between 4,000 and 5,000 years ago.

These trees, which are a nuisance when they jam farming equipment during plowing, contain a treasure trove of perfectly preserved information about what the Fens looked like thousands of years ago.

The Fen yew woodlands suddenly died about 4,200 years ago, when the trees fell into peat and were preserved. The researchers hypothesize that a rapid sea level rise in the North Sea flooded the area with salt water, causing the vast woodlands to disappear.

The climate and environmental information these trees contain could be a valuable clue in determining whether this climate event could be related to other events that happened elsewhere in the world at the same time, including a megadrought in the Middle East that may have been a factor in the collapse of ancient Egypt’s Old Kingdom. The researchers have published their findings in Quaternary Science Reviews.

The Fens of eastern England once held vast woodlands, study finds
Credit: Tatiana Bebchuk

Yew trees (Taxus baccata) are one of the longest-lived species in Europe, and can reach up to 20 meters in height. While these trees are fairly common in Cambridge College gardens and churchyards across southern England, they are absent in the Fens, the low-lying marshy region of eastern England. Much of the Fens was a wetland until it was drained between the 17th and 19th centuries using artificial drainage and flood protection. Today, the area is some of the most productive farmland in the U.K., thanks to its rich peat soil.

While the area is great for farming and does have its own charms, few people would describe the Fens as spectacular: for the most part, the area is extremely flat and dominated by fields of potatoes, sugar beet, wheat and other crops. But 5,000 years ago, the area was a huge forest.

“A common annoyance for Fenland farmers is getting their equipment caught on big pieces of wood buried in the soil, which can often happen when planting potatoes, since they are planted a little deeper than other crops,” said lead author Tatiana Bebchuk, a Ph.D. student from Cambridge’s Department of Geography. “This wood is often pulled up and piled at the edge of fields: it’s a pretty common sight to see these huge piles of logs when driving through the area.”

For farmers, these logs are a nuisance. But for Bebchuk and her colleagues, they are buried treasure. The Cambridge team approached several Fenland farmers and took samples of hundreds of logs that had been dug up and discarded, to find out what secrets they might hold.

The Fens of eastern England once held vast woodlands, study finds
Inner part of the pile of subfossil yew trunks. Note fresh chain-saw cuts after sampling cross-sectional disks. Credit: Tatiana Bebchuk

“I remember when I first saw this enormous pile of abandoned trees, it was incredible just how many there were,” said Bebchuk. “But when we got them back to lab, we were even more surprised: these trees were so well-preserved, it looked as if they were cut down just yesterday.”

To put current anthropogenic climate change in a long-term context of natural variability, scientists need accurate evidence from the past, and trees are some of the best recorders of past conditions: their annual growth rings contain information about temperature and hydroclimate for every growing season they witnessed. “But the further back in time we go, the less reliable evidence we have, since very old trees and well-preserved wood materials are extremely rare,” said Professor Ulf Büntgen, the senior author of the study.

However, analysis by the Cambridge Tree-Ring Unit (TRU) showed that the yew trees dug up from Fenland fields were very old indeed: some of these ancient trees were 400 years old when they died. The new find provides unique climate information for over a millennium from around 5,200 years ago until about 4,200 years ago, when much of the Fens was a woodland of yew and oak: completely different than it looks today.

“Finding these very  in the Fens is completely unexpected—it would be like turning a corner in rural Cambridgeshire and seeing an Egyptian pyramid—you just wouldn’t expect it,” said Bebchuk. “It’s the same with nature—wood rots and decomposes easily, so you just don’t expect a tree that died 5,000 or 4,000 years ago to last so long.”

The Fens of eastern England once held vast woodlands, study finds
Cross-section of a subfossil yew trunk after surface preparation. The disk contains 380 tree-rings, which means the tree was at least 380 years old when it died. Credit: Tatiana Bebchuk

Given that most of the Fens are barely above sea level, about 4,200 years ago, a sudden rise in sea level most likely killed the Fen woodlands. The period that the Fen woodlands died coincided with major climatic changes elsewhere in the world: at roughly the same time, a megadrought in China and the Middle East was a possible trigger of the collapse of several civilizations, including Egypt’s Old Kingdom and the Akkadian Empire in Mesopotamia.

“We want to know if there is any link between these climatic events,” said Bebchuk. “Are the megadroughts in Asia and the Middle East possibly related to the rapid sea level rise in northern Europe? Was this a global climate event, or was it a series of unrelated regional changes? We don’t yet know what could have caused these climate events, but these trees could be an important part of solving this detective story.”

“This is such a unique climate and environmental archive that will provide lots of opportunities for future studies, and it’s right from Cambridge’s own backyard,” said Büntgen. “We often travel all over the world to collect ice cores or ancient trees, but it’s really special to find such a unique archive so close to the office.”

More information: Sudden disappearance of yew (Taxus baccata) woodlands from eastern England coincides with a possible climate event around 4.2 ka ago, Quaternary Science Reviews (2023). DOI: 10.1016/j.quascirev.2023.108414

Journal information: Quaternary Science Reviews

How to help beneficial insects survive winter

November 25, 2023 · 4 minute read
How to help beneficial insects survive winter

Ladybugs are aphid eating all-stars. Understanding their winter behavior can help Texans protect them so they’ll be ready to fight off plant invaders in the spring. Credit: Texas A&M AgriLife photo by Laura McKenzie

While a decrease in insects as the weather cools is a plus to many people, Texans should keep in mind that beneficial insects in gardens and yards could use a little help.

“Although many  die off in the colder months, some hibernate while others are still active as needed,” said Sonja Swiger, Ph.D., Texas A&M AgriLife Extension Service entomologist and professor in the Department of Entomology in the Texas A&M College of Agriculture and Life Sciences, Stephenville.

Some insects have it harder than others depending on where they are in Texas. Some also migrate south to locations where the climate is typically milder. Whether you do a little or a lot, protecting beneficial insects benefits all Texans, Swiger said.

Five things to do right now

Swiger shared five things that Texans can do right now to help beneficial insects stay safe and survive the winter months.

Keep some weeds

While preparing for late autumn and winter, you may be tempted to eliminate weeds and prune back as many plants as you can. Don’t give in to temptation.

“Weeds, perennials and grasses all provide shelter for beneficial bugs in the winter,” Swiger said.

If you’ve already started to prune, pile up cuttings in a corner of the yard or garden and allow it to compost over the winter while providing insects a home.

Some beneficial insects including bees and wasps need the hollow stalks and stems of plants to lay their eggs.

Keeping some weeds around as well as planting perennials can essentially create an insect nursery. And when overwintering eggs, nymphs or larvae, and pupae hatch in the spring, you have a built-in flourishing insect population.

Plant for pollinators

Winter can be a marathon for some pollinators. Swiger said by planting cold-weather plants and trees that bloom later in the season, you can provide a  to keep bees and other pollinator insects going through the chillier months.

Regions where winters are on the milder side may see bees outside the hive more frequently. By having an all-season pollinator garden, you can provide them with the energy they need to get through the winter. They will then be ready to race to pollinate once temperatures warm.

Give ’em shelter

While some bees and wasps live in hives or nests, keep in mind that more often than not they are ground nesters. These pollinators will need some  and leaf litter to get through the winter.

“For those hive-dwelling pollinators, keep an eye out for their homes so you can put a plan in place to protect and shelter them,” Swiger said. “Walk around your property and look in eaves and sheds.”

You don’t want to enclose where they are, you just want to provide some protection from the elements. You can utilize wire mesh or add wood protrusions to provide some protection.

Either purchase or make “insect hotels.” These can be anything from what would serve the function of a traditional hive to those designed for the pollinators who prefer no roommates.

Ladybugs will look for crevices and somewhere with moisture when they need to hibernate for the . They cannot survive freezing temperatures, which means that under , a dark garden crevice or your home can all be attractive options for them.

Ladybugs can hibernate in large clusters and though they may look dead for months, most will awake in the spring and start snacking on pesky bugs. Ladybugs and lacewings are beneficial predators that form an insect army to devour aphids and other invaders.

Leave the leaves, please

Leaves make a great compost ground cover for beneficial insects and their different life stages. Composting leaves from trees such as oak will not only prepare your beds for spring but leaves also provide sustenance and protection for helpful insects now.

“Leaving 1 or 2 inches of  on the ground can make a big difference for insects,” Swiger said. “This can be concentrated to one area of the yard or a flower bed to keep an area looking tidy and to not impact the grass underneath.”

The caterpillars we see during the fall also need a pile of fallen leaves to overwinter to become the butterflies we’ll get to see in the spring. This is a great reason not to rake, or at least to leave a few piles around your yard.

Avoid pesticides when possible and read the label

Winter is also a time to avoid treating for pests around the house and inadvertently killing beneficial insects. Pest populations are generally lower during the colder months of the year and can be handled without insecticides. If insecticides are needed, they should be used intermittently or as a spot treatment.

“Keep in mind that there are more beneficial insects than ‘bad bugs’ in most gardens and yards,” Swiger said. “Many beneficial insects also feed on those less desirable ones.”

All pesticides are not created equal. It is important to read the label to ensure that you don’t inadvertently kill beneficial insects or the  that they live on or feed from. When in doubt, hold out.

“Protecting  through the colder months will not only help your own garden, but it also helps support agriculture in your area and that benefits everyone,” Swiger said.

Provided by Texas A&M University

Urban Forestry Program advances Virginia Tech’s Climate Action Commitment

November 15, 2023 · 4 minute read
Urban Forestry Program advances Virginia Tech’s Climate Action Commitment

Virginia Tech takes an integrated and adaptive approach to urban forest management, making use of continuous monitoring and assessments, providing opportunities for community engagement and expert collaboration, and managing the protection, planting, and maintenance of the over 11,500 trees that cover the Blacksburg campus. Responsible for this care is the Division of Campus Planning, Infrastructure, and Facilities’ urban forestry team – four individuals with expertise in arboriculture and urban forestry who strive to cultivate a low-risk, sustainable, resilient, and attractive urban forest that current and future generations of Hokies can utilize and enjoy.

On Nov. 6, Jamie King, urban forest manager and university arborist, provided an overview of the program to the Virginia Tech Board of Visitors, detailing the ways the team helps contribute to the Climate Action Commitment’s goal of carbon neutral agricultural, forestry, and land use operations by 2030.

“As urban foresters, we manage the entire population of trees at Virginia Tech,” said King. “The development of future plans and coordination with university and community partners allows us to properly care for the university’s trees while striving to meet the goals outlined in the Climate Action Commitment.”

Participants in the Arbor Day tree planting work with Jamie King, urban forest manager and university arborist, to plant trees in the old growth forest adjacent to Lane Stadium. Photo by Meghan Marsh for Virginia Tech.

Participants in the Arbor Day tree planting work with Jamie King, urban forest manager and university arborist, to plant trees in the old growth forest adjacent to Lane Stadium. Photo by Meghan Marsh for Virginia Tech.

In 2023, more than 500 trees were planted on the Blacksburg campus with plans for more during the upcoming planting season. Several of these plantings provided opportunities for student and community engagement, including a tree planting demonstration on Arbor Day and restoration efforts at Stroubles Creek.

The urban forestry team’s opportunities for community engagement expand beyond tree plantings. In October, King partnered with the College of Natural Resources and Environment to host a Homecoming Hike, touring alumni and visitors around the Blacksburg campus’ notable trees.

Partnerships such as that fuel the division’s urban forestry program’s success. A co-curriculum developed with the college creates experiential learning opportunities that help students refine their interests, skills, and professional character.

Alumni and visitors learn about campus trees during the Homecoming Hokie Hike. Photo by Luke Hayes for Virginia Tech.

Alumni and visitors learn about campus trees during the Homecoming Hokie Hike. Photo by Luke Hayes for Virginia Tech.

Other recent examples of community engagement include outreach and demonstrations with Radford High School and an urban forest tour for the Virginia Master Gardener College hosted by Virginia Cooperative Extension. During this tour, participants learned the history of notable trees at Virginia Tech in order to gain a greater understanding of the future of campus trees.

These academic and community partnerships also have led to recent achievements such as the Gold Leaf Award, a 2022 Virginia Trees for Clean Water Grant, and a 2022 Urban and Community Assistance Grant. These accomplishments have not only validated the team’s success, but also have allowed for the realization of plans for tree planting and the writing of a management plan that will assess the current tree inventory and the needs of campus trees.

Looking into the future, King notes three clear methods for achieving the university’s urban forestry goals:

  • Implement the urban forest master plan
  • Increase the urban tree canopy
  • Become the first accredited university urban forestry team
Jamie King, urban forest manager and university arborist, speaks to a group of alumni and visitors during the Homecoming Hokie Hike. Photo by Luke Hayes for Virginia Tech.

Jamie King, urban forest manager and university arborist, speaks to a group of alumni and visitors during the Homecoming Hokie Hike. Photo by Luke Hayes for Virginia Tech.

Adoption of the urban forest master plan is underway. This dynamic document – created with input from stakeholders including academic partners; students; every team in the Division of Campus Planning, Infrastructure, and Facilities; the Town of Blacksburg; and the larger Virginia Tech community – will serve as a guide to assess the university’s urban forest, report its benefits, and recommend paths forward.

“Urban forestry management is not just about planting trees. It’s about sowing the seeds of a healthier, happier, and more sustainable future for our campus,” said Wendy Halsey, assistant vice president for facilities operations. “By nurturing and preserving our assets, we’re investing in the well-being of our community, the quality of our environment, and the prosperity of generations to come.”

Efforts made by King and the urban forestry team are seen across campus as Virginia Tech continues to expand its campus tree canopy. As recommended in the Climate Action Commitment, the goal to reach 25 percent tree cover by 2050 will provide energy savings, offset campus carbon emissions, and provide numerous ecological services while also growing a lush, green campus environment.

Fall leaves on campus. Photo by Lee Friesland for Virginia Tech.

Fall leaves on campus. Photo by Lee Friesland for Virginia Tech.

Through the adoption of the urban forest master plan and the increase in the urban tree canopy, the urban forestry team is prepared to apply to the Sustainable Forestry Initiative’s Urban and Community Forestry accreditation program. Doing so would make Virginia Tech the first accredited collegiate program.

Over the past four years, the urban forestry team has worked diligently to resolve an extensive backlog of tree maintenance. While there is still work to be done, this investment has already contributed to a more resilient tree population. Looking ahead, the team will continue to care for existing trees on campus, grow the urban tree canopy, educate students, and engage in community outreach opportunities to create a more livable campus and a sustainable future.

Acorn by acorn, volunteers gather seeds to help save forests

November 15, 2023 · 5 minute read
Acorn by acorn, volunteers gather seeds to help save forests

On a sunny fall day at the edge of Shenandoah National Park, Jake Good, a nursery technician with the Virginia Department of Forestry, was getting acorns and chestnuts into the ground. More than three tons of them.

Here at the state’s nursery, about 140 miles southwest of Washington, this planting was an industrial operation. Poured from sacks into a machine, these seeds — future Chinese chestnut and white oak trees, many collected from donors around the state — were filtered into tubes that cast them on a row of earth about seven feet wide. Workers walked behind the machine,stepping on the acorns and chestnuts that were not covered by sufficient soil to grow.

Jim Ulmer, a Virginia Department of Forestry tree technician, steps on Chinese chestnuts just dropped onto the agency’s tree field to push them into the soil, while Jake Good loads nuts into the spreader tubes on the tractor. (Michael S. Williamson/The Washington Post)

Jim Ulmer, a Virginia Department of Forestry tree technician, steps on Chinese chestnuts just dropped onto the agency’s tree field to push them into the soil, while Jake Good loads nuts into the spreader tubes on the tractor. (Michael S. Williamson/The Washington Post)

The process wasn’t gentle but in about 18 months would result in a crop of seedlings that could be sold to landowners and the timber industry. In this way, Virginia’s arboreal future would be secure — thanks in part to acorn enthusiasts who donated more than a million specimens this year as part of a state program.

Good was already excited for early 2025, when the seedlings would be ready for harvesting and distribution: “You see them come up … that’s all my hard work.”

The operations at the Crimora nursery use contributions from an acorn donation program that Virginia’s forestry department has run for about a decade. Last year, the harvest was a formidable eight tons of acorns and nuts — enough to produce 1.5 million seedlings. This year, donors sent 12 tons.

Brittany Blackwell, a tree technician for the forestry department, holds bur oak tree seeds that were sent to the farm by a Virginia resident. (Michael S. Williamson/The Washington Post)

Brittany Blackwell, a tree technician for the forestry department, holds bur oak tree seeds that were sent to the farm by a Virginia resident. (Michael S. Williamson/The Washington Post)

No matter how many seedlings the program produces, however, there is room for more. Virginia has about 16 million acres of forestland and more than 108,000 residents employed in forestry and related industries. This is big business: The commonwealth’s forestry industry is worth $21 billion annually, according to forestry department spokesman Cory Swift-Turner.

This dollar amount is more than simply the value of the logging industry’s timber. Trees filter the water and air, reduce temperatures to decrease demand for electricity during hot months and bring in autumn’s “leaf-peeping” tourists who spend money across the commonwealth. Eventually, mature trees are felled to provide raw materials for builders, furniture makers and others.

A close-up of young Chinese chestnut trees at the Virginia Department of Forestry tree fields. (Michael S. Williamson/The Washington Post)

A close-up of young Chinese chestnut trees at the Virginia Department of Forestry tree fields. (Michael S. Williamson/The Washington Post)

With its collection program, Virginia facilitates this cycle, stabilizing the forest canopy as trees come and go. Money from the sale of seedlings also is invested back into the nursery, according to Swift-Turner.

One of the state’s more diligent acorn collectors is 69-year-old Mike Ortmeier, who started gathering them as a retirement project after leaving the Department of Energy in 2009. As a young boy, he and his twin brother had dreamed of planting forests, he said. Now, by contributing trees-to-be to the Crimora nursery, he was helping Virginia do just that — and fighting global warming in the process.

“I can’t go out and suck out every carbon molecule from the atmosphere,” Ortmeier said. “I see myself as a cog in the wheel.”

A self-described “super-collector,” Ortmeier said he gathers as much as 1,000 pounds of acorns and other tree seeds per year from public streets and other people’s property. Undertaking this mission, he faces an unexpected enemy: landscapers. Among the detritus cleared from gutters and lawns are the future of the state’s forests. If these countless acorns, nuts and seeds can be conveyed to facilities such as Crimora, new forests eventually will be born.

“All you have to do is get people to scoop this stuff off of their driveway,” he said. “It’s a contribution to the universe.”

Nursery technician Jake Good holds northern red oak tree seeds that were sent to the farm by a Virginia resident. (Michael S. Williamson/The Washington Post)

Nursery technician Jake Good holds northern red oak tree seeds that were sent to the farm by a Virginia resident. (Michael S. Williamson/The Washington Post)

Alexis Dickerson, the Potomac Conservancy’s senior director for community conservation, said the nonprofit helps facilitate acorn-collection programs throughout the D.C. region with its “Tomorrow’s Trees” program.

With expanding construction and development, Dickerson said, areas of the river’s watershed are paved over or converted into manicured lawns. When acorns fall, they cannot take root in asphalt or concrete or are dismissed as yard waste by landscapers. Any that become saplings may be devoured by deer displaced byloss of forests and habitat. As a result, the developed area becomes a “desert” that cannot produce the next generation of oaks and other species, according to Dickerson.

But people can help trees reproduce if they take the time to pick up acorns instead of treating them as refuse.

“It’s something they walk past every day that they might step over,” Dickerson said. “You can simply collect those things and get them to the right person that can create the next generation.”

Blackwell transfers bags of Chinese chestnuts into buckets before taking them to be planted. (Michael S. Williamson/The Washington Post)

Blackwell transfers bags of Chinese chestnuts into buckets before taking them to be planted. (Michael S. Williamson/The Washington Post)

Brittany Blackwell, one of the workers pushing seeds into the ground at the Crimora nursery, said she and her children went to a farm her family previously owned to gather Chinese chestnuts as part of this year’s collection effort. When the farm’s current owner thanked her for doing yard work, her response was: “What yard work?”

This wasn’t a chore. This was keeping an important species alive.

“We’re starting the future population,” she said.

As a tractor drops nuts on the ground, Blackwell uses her feet press them into the soil so that they can germinate. (Michael S. Williamson/The Washington Post)

As a tractor drops nuts on the ground, Blackwell uses her feet press them into the soil so that they can germinate. (Michael S. Williamson/The Washington Post)

Outdoor classroom creates a new generation of forest stewards

November 8, 2023 · 4 minute read
Outdoor classroom creates a new generation of forest stewards

Eight seniors in Jared Hughes’ forestry class measured the diameters of Douglas firs and discussed career options on a beautiful fall morning in the woods behind their school.

“Timber and forestry is relevant to our community and their backgrounds,” Hughes said.

Colton Brooks doesn’t mind being out of the classroom. Fishing, hunting, riding dirt bikes — recreating and working in the area’s forests is simply a way of life here. Brooks attends Priest River Lamanna High School and is enrolled in Hughes’ botany/forestry course that explores ecology and management.

“It’s way better out here,” Brooks said, with a slight grin.

Priest River is one of the rural epicenters of Superintendent Debbie Critchfield’s effort to push millions of dollars into career technical education to build-up programs that will train graduates to meet the needs of local industries.

Jared Hughes

Jared Hughes

In the panhandle region, that means timber production. And there’s plenty of opportunity. According to the American Forest and Paper Association, the U.S. forest products industry manufactures almost $300 billion in products a year and employs about 1 million workers. And Idaho is one of the top lumber producing states.

The state’s $45 million CTE grant program is called Idaho Career Ready Students. Last month, over $16 million was awarded to 11 initial programs. The second round of requests are due Nov. 1. Priest River is asking for $1 million.

“It really excites me that we … are focusing on rural, underserved districts for different career ready pathways,” Hughes said.

Training students in GIS mapping, ecology conservation and chainsaw operation could impact the town’s economic future. After the 2008 housing crash, the number of mills and the need for labor to produce wood products decreased. Although the demand for lumber slowed, the trees remain and young people continue looking for career opportunities, especially those that keep them in Priest River.

Several of the seniors in Hughes’ class want a job that has an opportunity to stay close to home. Although 17-year-olds Kemper Dabrowski, Kayden Reynolds and Brooks are part of multi-generational logging families, they are thinking about training as an electrical lineman, a diesel mechanic and an electrician.

Hughes has a plan — build a program that trains and inspires seniors to embark on natural resource careers.

On the 20-acre plot of forest behind the high school owned by the school district, Reynolds used an increment borer to drill half way into the Douglas fir. A core sample shows the 100-foot-tall tree is about 76 years old.

“What’s the DBH?” Hughes asked.

“19.8 inches,” Brooks responded. DBH stands for diameter at breast height, a measurement taken at 4.5 feet above the tree’s base.

Discussion turned to tree identification, and Hughes reminded students that hemlocks have a purple inner bark. The focus of Thursday’s class was timber cruising, a way to count volume. Reynolds said the total number of trees can be determined by counting up how many are in 1/10 of the area, and multiplying that by 10.

“That gives you the amount of trees in the whole acre,” he said.

According to Hughes, the goal is to provide industry partners with students who can step in “ready to go.” If the grant is approved, he plans to transform the acreage into a working forest — harvesting, planting and producing wood products.

What Priest River is requesting

Priest River is a rural, outdoor community that likes to hunt, fish and recreate. “Let’s create a workforce that manages our forest,” Hughes said, who has been teaching forestry for 15 years.

The high school has four certified CTE teachers. Hughes, who is certified in natural sciences, plans to obtain CTE certification to lead a new forestry program, which falls under the natural resource and plant soil science pathway. Although he taught forestry, there has never been an official forestry-related CTE pathway.

Colton Brooks is looking toward a career as an electrician. He comes from a multi-generational timber and logging family in Bonner County. Like his classmates, he hopes to find a career that keeps him close to home and out of the big cities.

Colton Brooks is looking toward a career as an electrician. He comes from a multi-generational timber and logging family in Bonner County. Like his classmates, he hopes to find a career that keeps him close to home and out of the big cities.

There was a time when Hughes taught 30 students but today it’s down to an average of 10-15 the last couple of years.

According to historical data, enrollment peaked around 513 students 20 years ago; today that number is around 316. In that same period, the number of students in the district shrunk by 27%, from 1,580 to 1,149.

The grant would fund four areas:

  • Curriculum: forestry science and management; forest products; wildlife ecology and management; GPS/GIS/mapping.
  • Equipment: lumber production equipment; equipment for cruise, soil and disease assessments; scaling, tree planting, forest ecology, wildlife science.
  • Building: a new building/complex, plus passenger vans.
  • Classroom equipment: safety equipment and classroom technology, like printers and plotters to handle large maps, GPS and drones for collecting forest data.

“It’s been a long time coming because Idaho has one of the largest percentages of national forests and endowment grant lands. This is surprising that we haven’t done it before. But the funding hasn’t been there,” Hughes said.

The communities of Orofino, Bonners Ferry, Potlatch, Troy, Deary and St. Maries have similar resources and the same potential as Priest River, he said.

The oldest river in North America flows through West Virginia

November 8, 2023 · 1 minute read
The oldest river in North America flows through West Virginia

When people from outside of West Virginia think of the Mountain State, they are constantly drawn to the scenery and diverse nature offered down every country road.

However, what some may not realize, is that they may come across one of the oldest country rivers in the world.

The New River, which flows through both West Virginia and Virginia, is not as new as its name portrays.

According to the National Parks Conservation Association, the New River is estimated to be anywhere from 260 to 375 million years old. This makes the New River the oldest river in North America. When looking abroad at other rivers around the world, the New River still remains in the top-5 oldest rivers at the number four spot.

This means the river was formed before the Triassic Period nearly 252 million years ago.

Many point to the New River Gorge Bridge when a thought of the New River pops up. However, the New River Gorge National Park and Preserve houses only 53 miles of the river that originates south of the Mountain State.

New River Basin Documents state how the river begins in northwestern North Carolina before flowing through southwest Virginia and along side country roads in West Virginia before joining the Gauley River to help spawn the Kanawha River.

The New River has grown alongside the land and people that inhabit the surrounding regions. Many spend time whitewater rafting or even just floating in the same river that their loved ones did many generations before. The New River was there long before West Virginia and will be there long after we are all gone.

One thing is for sure, while country roads will always take you home, country rivers will take you back in time.

Virginia Cooperative Extension fact sheet addresses new plant disease

November 2, 2023 · 2 minute read
Virginia Cooperative Extension fact sheet addresses new plant disease

Nurseries in Virginia and surrounding states have observed an uptick in vascular streak dieback on redbud (pictured), maple, and dogwood. Early symptoms of the disease include yellowing and discoloration of leaves and stunting and wilting. Photo courtesy of the Virginia Department of Agriculture and Consumer Services.

Throughout the past two years, nurseries in Virginia and surrounding states have observed an uptick in wilt and severe dieback on redbud, maple, and dogwood — Virginia’s state tree. In some cases, almost 100 percent of the stock was unsellable because of the damage.

To address this widespread issue, Virginia Cooperative Extension and Virginia Tech’s College of Agriculture and Life Sciences, in partnership with the Virginia Department of Agriculture and Consumer Services, have released a fact sheet that raises the awareness of vascular streak dieback and provides growers a number of tips on how to avoid and manage it.

Vascular streak dieback, as described in the new fact sheet, “Vascular Streak Dieback: An Emerging Problem on Woody Ornamentals in the U.S.” is a non-curable plant disease caused by a fungus. Early symptoms of the disease include yellowing and discoloration of leaves and stunting and wilting.

Vascular streak dieback has been difficult to diagnose, characterize, and manage because of a number of problems, including the fact that it is not culturable, said fact sheet co-author Elizabeth Bush, a senior research associate in the School of Plant and Environmental Sciences and diagnostician in the Plant Disease Clinic at Virginia Tech.

“Many microorganisms cannot be visualized on plant tissue, so culturing them out of plant tissue on culture media is necessary for diagnosis,” Bush said. “Plant diagnostic labs, such as the Plant Disease Clinic, use a variety of culture media to recover various fungal and bacterial pathogens.”

Vascular discoloration in redbud (A and B) and red maple (C and D). Photo courtesy of the Virginia Department of Agriculture and Consumer Services.

Vascular plant diseases, in general, are hard to treat as they attack the water-conducting tissue of the plant. A tree responds by blocking its vascular system to contain the disease. In doing so, the water supply to the plant is cut off, leading to wilt and dieback.

“So it’s not as easy as just pruning out the problem, like with a disease that causes a canker,” Bush said.

In the fact sheet, Bush and Devin Bily, a plant pathologist with the Virginia Department of Agriculture and Consumer Services, suggest several best practices to avoid the disease and preventative fungicides for use by nurseries. Unfortunately, there are no current recommended pesticide or cultural treatments for plants already exhibiting the symptoms of the disease. But, Bush said, it is good that nurseries are aware of this disease, are on the look-out, and know how to recognize the problem.

In addition to the fact sheet, the Plant Disease Clinic at Virginia Tech is collaborating with faculty in the School of Plant and Environmental Sciences to perform metagenomic analysis on plant samples diagnosed with vascular streak dieback. Metagenomic sequencing consists of obtaining nucleotide sequences of a pathogen directly from a plant sample without the need for culturing. It will help to further characterize the disease, which presents unique challenges since the pathogen is not culturable.

This work is being funded by the Virginia Agricultural Council.

The Importance of Bats

November 2, 2023 · 1 minute read
The Importance of Bats

Recently, the Virginia Department of Wildlife Resources sent an email about bats in Virginia. We wanted to pass on this great information on these essential members of our Virginia ecosystem!

Protections Under the ESA Have Helped Virginia’s Bats Weather White-Nose Syndrome

While there’s not much that can currently be done to battle white-nose syndrome in Virginia’s bat populations, protections under the ESA have helped the bats persevere through the white-nose crisis. READ ON


DWR’s Bat Guide

Get to know the bats of Virginia in DWR’s Guide to the Bats of Virginia, a comprehensive look at the resident bat species of the commonwealth. LEARN MORE


Bats: The Myths and Truths

Do all bats have rabies? Will bats fly into your hair? You’ve got bat questions. We’ve got bat answers. READ ON


Learn More About Bats!

Few of nature’s animals are as misunderstood as bats. This article from the U.S. Fish and Wildlife Service sets the record straight and highlights the importance of bats. Though often feared and loathed as sinister creatures of the night, bats are vital to the health of our environment and our economy. Here you’ll learn more about why bats are so essential, the threats they’re facing, how we’re conserving bats, and how you can help create a bat-friendly environment. LEARN MORE

Invasive and ubiquitous, English ivy can hurt trees and plants. Removing it isn’t easy

October 27, 2023 · 3 minute read
Invasive and ubiquitous, English ivy can hurt trees and plants. Removing it isn’t easy

English ivy (Hedera helix), a heavy, woody vine with handsome, dark-green, waxy leaves, is believed to have been brought to the New World by European colonists in the 1700s. They likely appreciated its shade tolerance, versatility as both a ground cover and climbing vine, and rapid growth.

But today, it’s classified as an invasive species in many parts of the United States, where it grows quickly and can suffocate, starve and weaken trees.

If you live in one of those regions, you’ve likely seen it climbing tree trunks. And you might be painfully aware of how difficult it is to eradicate.


The vine snakes its way up the tree and under its bark, firmly attaching its roots and tendrils as it grows. Simply yanking the ivy would also remove the bark, which serves as the tree’s vital protection from insects, diseases and the elements. In addition, the ivy’s densely packed leaves can block sunlight from reaching the tree, inhibiting photosynthesis, which diminishes the nutrients it can produce.

The weight of the vine weakens branches and, during severe weather, can topple the tree, placing people and property at risk. It’s also a host plant for insect pests that could attack the tree, and mosquitoes that could attack you.

Because its trunk and vines cling sturdily to surfaces via three different methods — aerial roots, tendrils and a sticky substance called glycosides – removing English ivy should be done carefully to avoid damaging trees.


Always wear gloves when handling English ivy, as the glycosides will stick to and irritate your skin. Some people also report breathing difficulties when working around the plant; a mask will offer protection. And if you are allergic, it would be best to solicit someone else to tackle the job.

Sever the ivy all around the tree, 3 feet off the ground, using loppers or a hand saw. Then, one by one, carefully separate the detached upper part of each branch from its lower portion, which will still be growing from the ground.

Next, working your way around the tree’s base, dig up all the ivy’s roots and remove the plant from the soil. Keep an eye out for new growth from any roots you might have missed, and pull up new sprouts as you see them.

Allow the severed upper portion of the ivy to remain on the tree. Over the course of about a year, it will die and release its stronghold from under the bark. The withered foliage will eventually blow away.


English ivy growing up the side of a brick house risks damage to the structure. As the plant climbs walls, its tendrils become anchored into cracks or gaps in the mortar, which will weaken if the ivy is left in place. Simply pulling the vines down would likely damage that mortar, as well.

Avoid the temptation to apply chemical herbicides, as they may stain the bricks. The leaves’ waxy coating protects it from most weed killers, anyway.

Instead, start by treating the vine as you would if it were growing on a tree: Sever it at the point where its trunks meet the wall and remove the lower portions from the soil.

Next, clip each vine as closely to the wall as possible, but allow the small roots to remain embedded in the mortar for a few weeks. As soon as those roots darken and die, use a stiff brush and detergent to safely scrub them away.

Be sure to assess any damage caused by the plant and make repairs as soon as possible.


Jessica Damiano writes the award-winning Weekly Dirt Newsletter and regular gardening columns for The AP. Sign up here to get weekly gardening tips and advice delivered to your inbox.

The trees arrived with Polynesian voyagers. After Maui wildfire, there’s a chance to restore them

October 27, 2023 · 6 minute read
The trees arrived with Polynesian voyagers. After Maui wildfire, there’s a chance to restore them

LAHAINA, Hawaii (AP) — For people around the world, the green leaves that sprouted from a scorched, 150-year-old banyan tree in the heart of devastated Lahaina symbolized hope following Maui’s deadly wildfire this summer. Teams rushed to flood its roots with water, hoping to save a magnificent tree that had provided shade for community events, a picturesque wedding venue and a popular backdrop for posing tourists.

But the fire also nearly wiped out another set of trees, one with a much longer history in Lahaina and a greater significance in Hawaiian culture: breadfruit, or ulu, which had given sustenance since Polynesian voyagers introduced it to the islands many centuries ago. Before colonialism, commercial agriculture and tourism, thousands of breadfruit trees dotted Lahaina; the fire charred all but two of the dozen or so that remained.

Now, as Maui recovers from the deadliest U.S. wildfire in more than a century, one that left at least 98 people dead, a band of arborists, farmers and landscapers has set about trying to save Lahaina’s ulu, kukui nut and other culturally important trees, in some cases digging down to the roots of badly burned specimens to find live tissue that could be used to propagate new shoots.

They see the destruction as a chance to restore the trees to Lahaina, to teach about their care and use, and to reclaim a bit of the town’s historic identity amid a larger discussion about whether the community’s reconstruction will price out locals and Hawaiian culture in favor of deep-pocketed outsiders seeking a slice of tropical paradise.

“Even in this tragedy and the destruction, there is a lot of hope in our communities that there is opportunity here to bring awareness and appreciation and incorporation of some of our values and history and identity,” said Noa Kekuewa Lincoln, an associate researcher of indigenous crops at the University of Hawaii at Manoa.

The banyan tree at the center of Lahaina was a sapling when it was planted in 1873 — a quarter century before the Hawaiian Islands became a U.S. territory and seven decades after King Kamehameha declared Lahaina the capital of his kingdom. It was a gift shipped from India to commemorate the 50th anniversary of the first Protestant mission in Lahaina.

A breadfruit tree at Noho'ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii. (AP Photo/Mengshin Lin)
A breadfruit tree at Noho’ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii. The wildfire fire nearly wiped out a set of trees, one with a long history in Lahaina and a great significance in Hawaiian culture: breadfruit, or ulu, which had given sustenance since Polynesian voyagers introduced it to the islands many centuries ago. (AP Photo/Mengshin Lin)

The sprawling tree is beloved, towering more than 60 feet (18 meters) and spanning nearly an acre with aerial roots descending from its boughs. It has provided shade for locals and tourists alike in a town whose name means “relentless sun.” But for some it also continues to represent the colonization that eventually transformed Lahaina into a travel destination.

By contrast, researchers believe breadfruit and kukui nut — now the state tree of Hawaii — were among the many edible plants Polynesian voyagers brought around 1,000 years ago. Such imports could have been carried across the ocean, wrapped in rotted coconut husk and dried leaves and protected in a woven coconut basket.

Hokuao Pellegrino poses for portrait in front of his first breadfruit at Noho'ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii. (AP Photo/Mengshin Lin)
Hokuao Pellegrino poses for portrait in front of his first breadfruit at Noho’ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii. Researchers believe breadfruit and kukui nut — now the state tree of Hawaii — were among the many edible plants Polynesian voyagers brought around 1,000 years ago. (AP Photo/Mengshin Lin)

Kukui nut oil was used for torches — kukui is known as the “tree of light.” Other uses included wood for canoes, dyes for tattoos and bark infusions for preserving fish nets.

Ulu can grow to 60 feet (18 meters) tall, with large dark green leaves, and each can bear hundreds of pounds of breadfruit. A staple in some tropical countries, the fruit looks like an oversized, scaly lime. It is typically eaten cooked and is starchy, like potatoes or bread. It has a short shelf life, rotting within 48 hours of ripening.

Kaipo Kekona, a ninth-generation Lahaina native, has led efforts to restore its ancient food forests for several years. He said ulu can be made into dishes resembling mashed potatoes, French fries, mousse, hummus, cakes, pies and chips, and that it can help ensure food security when other industries fail, such as tourism during the pandemic or after the wildfire.

“When we look at reforestation efforts in our town, reclamation of ulu and its historical value, it can be complemented by the evolving palates of our community,” Kekona said.

The footprint of the burn zone largely overlaps what is known in Hawaiian history as Malu ulu o Lele: “the shaded breadfruit grove of Lele,” Lele being an earlier name for Lahaina. By the late 19th century many of those trees had been burned to make way for sugar plantations. Fresh water sources at streams and canals were diverted. Development transformed the landscape into a tourism destination with far fewer trees.

Breadfruit trees at Noho'ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii.  (AP Photo/Mengshin Lin)
Breadfruit trees at Noho’ana Farm on Tuesday, Oct. 10, 2023, in Waikapu, Hawaii. “You probably don’t want to put breadfruit in a really high traffic area,” said Hokuao Pellegrino, an ethnobotanist who has helped in the volunteer effort and who has 22 breadfruit trees on his own farm in Waikapu, on the other side of the West Maui Mountains from Lahaina. (AP Photo/Mengshin Lin)

Efforts to revive the banyan and other important surviving trees have included trucking in water, applying compost extract and testing soil. The volunteers working to save Lahaina’s breadfruit have dug down to extract viable root matter. In one case, they peeled back asphalt that butted against a charred breadfruit trunk. Underground, they found life.

The samples they collected are now in a University of Hawaii lab in Hilo, on the Big Island. Lincoln projects hundreds of trees could be propagated, with seeds or saplings given to homeowners seeking to replant their properties.

But replanting breadfruit in urban areas comes with challenges, said Steve Nimz, an arborist on Oahu who has been helping restore Lahaina’s trees.

When ripe breadfruit falls, it splats and rots in an unsightly, gooey, fragrant mess. Trees planted near a sidewalk or public area could pose a threat to passersby, as some varieties have fruits weighing up to 12 pounds (5.5 kg). Falling breadfruit can cause serious injury.

“You probably don’t want to put breadfruit in a really high traffic area,” said Hokuao Pellegrino, an ethnobotanist who has helped in the volunteer effort and who has 22 breadfruit trees on his own farm in Waikapu, on the other side of the West Maui Mountains from Lahaina. “But restoring some of the breadfruit groves as part of the individual homeowner’s landscape, now that is a worthy cause, because those can be managed a little bit better.”

Pellegrino said the efforts to replant breadfruit in Lahaina should also come with efforts to teach people about its care and its uses: “We want people to use the breadfruit. We don’t want it just to be in the landscape.”

FILE - A man reacts as he sits on the Lahaina historic banyan tree damaged by a wildfire on Friday, Aug. 11, 2023, in Lahaina, Hawaii.  (AP Photo/Rick Bowmer, File)
FILE – A man reacts as he sits on the Lahaina historic banyan tree damaged by a wildfire on Friday, Aug. 11, 2023, in Lahaina, Hawaii. After the deadly wildfire that destroyed the historic town of Lahaina this summer, people across the world focused their attention on the green leaves sprouting from the scorched, 150-year-old banyan tree as a symbol of hope. Arborists are also trying to save another set of trees, ones with greater significance in Hawaiian culture, such as breadfruit and kukui nut trees introduced to the island by Polynesian voyagers long ago. (AP Photo/Rick Bowmer, File)

But for now, many are more focused on housing and cleaning up after the disaster than on what trees to eventually plant. Pellegrino, who calls himself an outsider because he’s not from Lahaina, says reintegrating breadfruit and restoring wetlands, canals and streams could bring a new future for the town.

“It’s about reclaiming the identity of that place,” Pellegrino said.


Komenda reported from Tacoma, Washington.

VCU, U.S. Fish and Wildlife Service partner to restore migratory fish in Virginia rivers

October 12, 2023 · 2 minute read
VCU, U.S. Fish and Wildlife Service partner to restore migratory fish in Virginia rivers

The partnership will support the conservation of American shad and other species.

The VCU Rice Rivers Center will receive a $300,000 federal award in support of a new partnership to advance conservation of the iconic and culturally significant migratory American shad and river herring fish species in Virginia rivers.

The Virginia Shad and River Herring Research Initiative is a collaboration between the Rice Rivers Center and the U.S. Fish and Wildlife Service.

“The new partnership between [the Fish and Wildlife Service] and VCU is the most significant step in a decade toward restoration of the iconic American shad and other migratory shads and herrings to Virginia waters,” said Greg Garman, Ph.D., director of the Rice Rivers Center. “It is difficult to overstate the environmental, cultural and economic importance of these species historically. The Rice Rivers Center is excited to be a part of ‘turning the tide’ for these native fishes after over a century of declines from overfishing, pollution and habitat loss.”

Garman added that VCU is grateful for the support of the initiative by Sens. Tim Kaine and Mark Warner and Rep. Rob Wittman.

Migratory American shad, hickory shad, alewife and blueback herring once supported vital commercial and subsistence fisheries in Virginia. Beginning in the 20th century, however, a combination of overfishing, pollution, habitat loss, dams and the introduction of non-native predators diminished these once-significant fisheries.

Migratory American shad in the James River. (Photo by Virginia Department of Wildlife Resources).

Migratory American shad in the James River. (Photo by Virginia Department of Wildlife Resources).

The Fish and Wildlife Service and the Rice Rivers Center will engage with a broad consortium of state agencies, tribal governments, academia and nongovernmental organizations to further explore the declines in these native fishes. Biologists also will propose conservation measures to reverse population trends and help recover these valuable and iconic native species to Virginia’s coastal rivers.

“Impact-focused collaborations like this are driving VCU’s growing reputation for research,” said Fotis Sotiropoulos, Ph.D., provost and senior vice president for academic affairs. “VCU’s ranking as one of the nation’s top 50 public research universities was earned by focusing on real-world challenges like the survival of these historically- and environmentally-significant migratory fish species. We are honored to work with so many partners on this priority project of sustainability.”

The Rice Rivers Center, part of VCU Life Sciences, is located in Charles City along the James River. It supports applied research, scholarship and student training across diverse disciplines, including water resources, climate science, wildlife conservation, wetlands restoration and environmental technology.

Doubling efforts to save ash trees

October 12, 2023 · 3 minute read
Doubling efforts to save ash trees

A metallic-green invasive insect, the emerald ash borer, has been wiping out ash trees as it has spread through Virginia over the past 15 years. The destructive wood-boring beetle has attacked forests from the mountains to the coast – including stands within Virginia State Parks.

With assistance and training from the Virginia Department of Forestry, state parks staff are fighting back, armed with insecticides as well as a tiny, parasitoid wasp.

An ash tree native to Virginia has no natural defenses against the emerald ash borer. The larvae bore into and feed on its inner bark and water system, leaving squiggly S-shaped tunnels, or galleries, in their wake. The galleries encircle the inner vascular tissue of the tree, choking it off from water and nutrients and ultimately killing it.

Last year, ecologists in the Virginia Natural Heritage Program at DCR reported that green ash trees at Machicomoco State Park in Gloucester County were infected with emerald ash borer. These trees had been some of the state’s last remaining healthy populations of ash.

In July, a DCR team began treating dozens of green ash in two areas at Machicomoco by injecting an insecticide into the tree’s vascular systems, where it will kill the borer larvae.

Staff also treated infected green ash at four different areas of Chippokes State Park in Surry County.

Katlin DeWitt, a forest health specialist at DOF, has helped to administer the treatments at state parks and assisted DCR staff.  “We’re very invested in protecting these trees.” DeWitt said. “We like to work with other state agencies and help save trees on state lands.”

DeWitt said the chemical treatment being used is highly effective for controlling emerald ash borer. “The trees we treated are a lot healthier,” she said. “And we can see the decline on other trees that have not been treated.”

In some cases, the insecticide treatment can be complemented with biological control, or biocontrol, to target the following generation of borers before they can hatch.

One natural enemy of the emerald ash borer is a parasitoid wasp called Oobius agrili. These wasps, approved for release and provided by the USDA Animal and Plant Health Inspection Service, lay their eggs inside the eggs of the emerald ash borer. When the wasp larvae emerge, “Her developing young will kill the emerald ash borer,” DeWitt said.

“We can’t go out and chemically treat every tree in the forest. The little wasps will help fill the gap and provide another level of protection out there for trees we weren’t able to treat.”

ash tree treatment2

White and blue ash trees have been treated for protection against the emerald ash borer for several years now at Southwest Virginia Museum, Natural Tunnel and Grayson Highland state parks.

Jordon Blevins, district resource specialist for the Southwest Region of Virginia State Parks, said that the white ash trees at Southwest Virginia Museum still appeared to be healthy after a few years of treatments.

Saving larger trees in the mountains will help protect the scenic views in addition to preventing damage to the ecosystems, he said.

Nationwide, the emerald ash borer has taken a major toll on forestry and lumber industries, threatening to permanently alter our forest ecosystems.

Of the six species of native ash to Virginia, all are considered endangered, according to DeWitt. “Losing any species that’s native has a whole cascade of effects from an ecosystem perspective,” she said.

Losing ash is even more critical when the species makes up a significant part of a natural community that is rare. A natural community is an assemblage of native plants and animals that occurs repeatedly on the landscape under similar ecological conditions. At Machicomoco and Chippokes, the ash stands are located in the globally rare natural community type called Coastal Plain Calcareous Seepage Swamp Forest.

Erik Molleen, district resource specialist for the Tidewater Region of Virginia State Parks, said that when large ash trees in this natural community die, more sunlight will be let in, promoting the spread of non-native, invasive plant species. “That will open up the canopy and change the herbaceous vegetation. It’s very important that we protect the green ash,” he said. “By protecting that one tree, we’re also protecting the other species in that globally rare ecosystem.”

It Starts In Your Yard

October 4, 2023 · 2 minute read
It Starts In Your Yard

This week’s article is by our guest writer Ingrid Girardi.

The forests, beaches, mountain ranges, and meadowlands have always been places of incredible beauty. What is it about these wild landscapes that I and so many others love? Possibly it’s the diversity of life they all share. There’s always something new to discover. This love led me to an Instagram account, @homegrownnationalpark where I discovered people creating such natural spaces right in their own backyards!

As it turns out, there is so much more than beauty and curiosity that make these wild areas amazing. They are the places that sustain all life! This was evident after hearing the author, professor of entomology, and creator of the aforementioned Instagram account, Doug Tallamy, speak last week. It was a very hopeful presentation explaining the positive impact everyone can have on the future of the planet just by changing our perspective on how we approach our own spaces in just a few ways.

An overall theme of Doug’s research is how to work with and not against the natural world. Native plants are the main focus of this idea. Collectively, the yards we all have, from a container to a huge plot of land, have a massive impact on the diversity of life on this planet. Doug writes extensively about this in his book Nature’s Best Hope: A New Approach To Conservation That Starts In Your Yard.

Planting natives, especially keystone species, wherever you are able will have a positive ripple effect on the web of life. Many species of insects rely on specific plants from which they have evolved. When these host plants are removed and replaced with exotics, the insects die and the creatures who rely on those insects die. Doug speaks extensively about the tiniest critters appearing to be the most important.

A great way to ensure the survival of vital food sources for birds and other creatures is to leave the debris that falls from your plants throughout the seasons in place. The leaves on the ground in fall provide the perfect habitat for so many small animals and keeps the soil permeable. This is where a slight change in perspective is needed. Rather than seeing a mess of leaves, you will now see all the biodiversity you helped steward!

One more simple way to increase the biodiversity in your space is to avoid herbicides, pesticides, and other chemical inputs. Nature has her own exquisite way of balancing herself out. This is overwhelmingly evident in the beautiful natural places we all admire and long to linger.

For more information, check out native plant resources in Richmond by visiting the Virginia Native Plant Society, More resources can be found on Doug Tallamy’s website

‘Lost’ Brazilian holly tree species found again after nearly 200 years

October 4, 2023 · 3 minute read
‘Lost’ Brazilian holly tree species found again after nearly 200 years

An expedition team has found a rare Brazilian tree that botanists thought might be extinct after nearly two centuries without a confirmed sighting.

The Pernambuco holly tree (Ilex sapiiformis), which can grow to a height of 12 meters (nearly 40 feet), was found again in March in northeast Brazil by a team led by ecologist Gustavo Martinelli. They located four trees, two male and two female, in a fragment of forest next to a sugarcane plantation in the municipality of Igarassu, part of the greater metropolitan area of the city of Recife in Pernambuco state.

The Pernambuco holly (Ilex Sapiiformis), found again in Brazil’s Atlantic Forest. Image courtesy of by Fred Jordão.

The Pernambuco holly (Ilex Sapiiformis), found again in Brazil’s Atlantic Forest. Image courtesy of by Fred Jordão.

“The moment when we found Ilex sapiiformis, it seemed that the world had stopped turning its gears,” local researcher Juliana Alencar said in a statement. “Finding a species that hasn’t been heard of in nearly two centuries doesn’t happen every day. It was an incredible moment, and the emotion of it was felt throughout the entire team. When I looked at Professor Milton Groppo, I saw that he had tears in his eyes.”

“It was like finding a long-lost and long-awaited relative that you only know by old portraits,” said Groppo, a researcher at the University of São Paulo.

The Pernambuco holly was described by science in 1861, from a specimen collected in 1838. That original specimen was the only confirmed record until now. The team spent months searching herbarium records globally before an unidentified 1962 sample provided a lead that helped Alencar pinpoint survey areas.

Juliana Alencar stands next to the holly trees, found in a patch of forest by the river. Image courtesy of Gustavo Martinelli.

Juliana Alencar stands next to the holly trees, found in a patch of forest by the river. Image courtesy of Gustavo Martinelli.

The team searched four areas in the Recife metropolitan region. Identifying the inconspicuous greenish flowers among similar holly species was challenging, Martinelli said, but the researchers spotted the four plants on their second day in the field.

“It was exciting when we found the first individual of Ilex sapiiformis, thanks to the keen eyes of [field assistant] Mr. Lenilson [Barbosa dos Santos], who was able to find some white flowers in a tree alongside the dirt road,” Groppo said.

The trees live in an area once dominated by tropical Atlantic Forest but that’s now primarily urban sprawl with sugarcane plantations dispersed throughout. Less than 7% of the original forest biome remains, most in fragments of less than 50 hectares, or about 120 acres.

The area around Igarassu, Brazil, where the trees were found. Only a few patches of Brazil’s Atlantic forest remain.

The area around Igarassu, Brazil, where the trees were found. Only a few patches of Brazil’s Atlantic forest remain.

Since the expedition, one of the trees has already died, Martinelli told Mongabay. The trees grow close to a river, and he said he suspected that flooding had inundated the roots and killed the tree.

“The Pernambuco holly is in an emergency situation now,” Martinelli said.

Researchers want to search for more trees, work with the landowner to better protect the site, and collect seeds to germinate more trees. However, this is all expensive, Martinelli said, and they’re still determining how to fund these efforts.

Re:wild, a U.S.-based NGO, said it’s working with Martinelli to get the area where the Pernambuco holly was found listed as an Alliance for Zero Extinction site since it’s the only known area where the plants live. If the area becomes an AZE site, that could open up more resources to help the Pernambuco holly.

Only 3 individual Pernambuco Holly (Ilex Sapiiformis) trees are known to exist. Photo courtesy of Fred Jordão.

Only 3 individual Pernambuco Holly (Ilex Sapiiformis) trees are known to exist. Photo courtesy of Fred Jordão.

The holly is one of the 25 “most wanted” lost plant and animal species targeted for rediscovery by the Search for Lost Species project. It’s the ninth that’s been “rediscovered” since the initiative began in 2017. Others include the Somali sengi (Elephantulus revoilii), the silver-backed chevrotain (Tragulus versicolor), the velvet pitcher plant (Nepenthes mollis), and Jackson’s climbing salamander (Bolitoglossa jacksoni)

Martinelli said he’s found more than 20 species lost to science during his career. “I love the challenge of finding lost plants,” he said.

“It’s incredible that the Pernambuco holly was rediscovered in a metropolitan area that is home to nearly six million people,” said Christina Biggs, lost species program officer at Re:wild. “Even if a plant hasn’t had a confirmed sighting in 186 years, it could still be hanging on in the last vestiges of the wild somewhere, and this tree is a perfect example of why it’s important to keep looking.”

As critical pollinator populations decline, cities and campuses find ways to encourage bees, butterflies and bats

October 4, 2023 · 11 minute read
As critical pollinator populations decline, cities and campuses find ways to encourage bees, butterflies and bats

Cities and college campuses across the region have been certified as “bee-friendly.” Their efforts include reducing the use of pesticides, allowing native species to thrive, and educating residents and students about how best to help pollinators.

As morning clouds begin to dissipate and the sun begins to shine, raising the temperature to a warm 85 degrees, Lucy Hudson stands next to the pollinator habitat that covers a corner of Miller Center, the headquarters of Lynchburg’s Department of Parks and Recreation.

Hudson, a park services specialist for the department, gazes at the wide array of flowers and herbs like a proud mother. The area around her is buzzing with activity, as sweat bees and bumblebees float from blossom to blossom and plant to plant. The colors range from pink and purple to red and yellow. She points out the African blue basil and the coneflowers as both enjoyed by bees and a great source of food.

African blue basil at the Miller Center. Photo by Zack Denton.

African blue basil at the Miller Center. Photo by Zack Denton.

After taking a class on bees, Hudson decided that it was important in her work to ensure that Lynchburg would become more bee- and pollinator-friendly. It has been a labor of love as she has spent the last several years planting and digging in the various pollinator habitats around the city, including many located at community centers and parks such as Riverside Park.

The habitats are eye-catching additions to their surroundings. But they were created for a specific purpose: to address the fact that the plight of bees and other pollinators has gone downhill and their future is uncertain.

Over the last few years the United States, as well as the rest of the world, has seen a decline in the number of pollinators. The most commonly known pollinators are bees and butterflies, but birds, bats and other foraging animals are also pollinators.

According to a recent U.S. Geological Survey-led study, the once common western bumblebee has declined by 57%. Much of the general decline can be attributed to an increase in temperatures, the use of pesticides and overall human activity.

Humans depend heavily on the activity of pollinators for survival yet are a large contributor to their decline. An ever-expanding population in the U.S. is constantly widening the spaces where humans live, removing native grasses and flowers that pollinators depend on.

Federal agencies including USGS, the U.S. Fish and Wildlife Service and the U.S. Department of Agriculture have been warning for years of the danger that further decline of pollinators poses to both the economy and the survival of humans and wildlife as a whole.

In Virginia, a number of colleges, universities and municipalities have taken steps to try and help pollinators continue to play their part in the ecosystem. Randolph College in Lynchburg was the first university in the state to be certified “bee-friendly” in 2016 by Bee City USA, an initiative of the Xerces Society, an organization focused on the preservation of invertebrates and their habitats.

To date, there are 191 cities across the United States that can boast of being a Bee City; 13 of those are in Virginia. In addition, there are 173 college and university campuses that can lay claim to being a Bee Campus, with six of them in Virginia.

Randolph College

Randolph College maintains several, rain, organic and pollinator habitats around campus and the community, says Lindsey Van Zile, the school’s sustainability and campus projects. The school also has areas where grasses aren’t mowed so that they attract pollinators, touching only those areas necessary to harvest seeds for future growth. The school also maintains a greenhouse for seeding flowers and plants that are then planted in the pollinator habitats.

An important key to the effort’s success is the education of the public. Van Zile says that the college provides information to both the public and students about the role that pollinators play in the ecosystem. Students have shown great interest in getting involved, she says, and tend both the habitats and the greenhouse.

Since she started her position at Randolph College at the end of October 2022, Van Zile has seen an increase in the instances of pollinators around campus and in Lynchburg. She says that she has seen the greatest increase in the unmowed areas where the blooms in those grasses have attracted more bee visits.

A sign at the Miller Center in Lynchburg explains the city’s pollinator-friendly initiatives. Photo by Zack Denton.

A sign at the Miller Center in Lynchburg explains the city’s pollinator-friendly initiatives. Photo by Zack Denton.


Lynchburg became a Bee City in 2019. The city was already taking steps to become more pollinator-friendly when it was approached by the Xerces Society, Hudson says.

Many of Lynchburg’s efforts have been in tandem with those of Randolph College. All across the city, pollinator habitats have been planted with native flowers and herbs that provide shelter and food. Hudson says that the Department of Parks and Recreation also has encouraged the city to be cognizant of the types of pesticides that it uses, and how much or how often it sprays them in the gardens.

Also, like Randolph, Lynchburg has designated certain areas within Riverside Park as no-mow zones. This both allows for the attraction of pollinators and reduces some of the gasoline fumes being released into the air.

A no-mow area at Riverside Park in Lynchburg. Photo by Zack Denton.

A no-mow area at Riverside Park in Lynchburg. Photo by Zack Denton.

Education also has been a key element in Lynchburg’s sustainability efforts. Hudson says that the city placed signs within the un-mowed areas, explaining that they’re being allowed to grow so that they can attract bees and other pollinators. The city also has engaged in efforts to educate the public on how to plant beneficial plants, flowers and trees and how to maintain their own gardens at home.

Hudson says she has been working for years on her own garden to make it more pollinator-friendly. She says that bees native to Virginia are solitary, meaning they don’t have a hive structure, and the young depend on their mother to find and provide food. If she is unable to do so, both mother and the babies will die. This point emphasizes the importance of maintaining pollinator habitats and un-mowed grasses so that our pollinators can feed themselves and thrive, thus also benefiting humans in the long run.


In the fall of 2020, the city of Martinsville became a Bee City. Cindy Edgerton, chairperson of the city’s Bee City Committee — and also a member of several local garden clubs — says that she approached the city council to propose that the city become a Bee City. Given her involvement with garden clubs, she had been thinking for some time about how to protect pollinators.

To her delight, the city council agreed to apply, but with one caveat: The city did not want to spend any money.

While this presented a challenge, the community dove in head first. Edgerton says that the committee relies heavily on education, from setting up booths at public events — she says that a bee costume is in the works to add a bit of flair — to providing practical advice to residents as to how they can help protect pollinators. She says that she tells people that they can mow their lawns, but the grass should not be cut below 4 inches. She also recommends that herbicides be used instead of pesticides in personal gardens and on lawns.

The city also has several baseball fields that have fallen into disuse. A plethora of clover has overgrown the fields, and the city has decided to allow that to grow so that it can be a source of food for pollinators, Edgerton says.

Edgerton adds that the community is truly excited to be involved. Schools, museums and even the chamber of commerce have been heavily invested in the educational aspect of the efforts.

Virginia Tech

Virginia Tech was designated a Bee Campus last year.

The university has planted and maintains habitat gardens around the campus, says Margaret Couvillon, an assistant professor in the Department of Entomology who focuses on pollinator biology and ecology. While Tech began by planting flowers such as lavender, it has since diversified its array of pollinator-attracting perennial flowers, plants and trees.

Couvillon and her team have also worked with the campus grounds crew to reduce the pesticides used in and around their gardens. While spraying may kill the insects that damage flowers and plants, it also can kill bees and other pollinators.

These efforts are a long-term project, she says. Tech is developing a method to measure the increase in pollinators as a result of the school’s efforts. Though it has only been a year since Virginia Tech was certified as a Bee Campus, there have been intangible results, Couvillon says.

“This has brought together Hokies around a common cause,” she says.


In May 2022, the Roanoke City Council adopted a resolution declaring Roanoke a Bee City. The Roanoke Valley Garden Club and others had been advocating for the city to become a pollinator-friendly community for many years, and in May 2023, the city officially launched its project.

The city has planted pollinator habitats in various locations around Roanoke and has posted signage alerting the public to its status as a Bee City. Photo by Megan Schnabel.

The city has planted pollinator habitats in various locations around Roanoke and has posted signage alerting the public to its status as a Bee City. Photo by Megan Schnabel.

“It’s important to protect and sustain pollinator habitats,” says Leigh Anne Weitzenfeld, the city’s sustainability coordinator.

The city is in the process of forming its Bee City committee, which will include city employees and members of area garden clubs.

One of the committee’s main goals will be to educate the public on the role that pollinators play in sustainability. The city also has put out a brochure explaining which native plants, flowers and trees should be planted in home gardens to attract pollinators.

In partnership with local garden clubs, the city has planted pollinator habitats in various locations across Roanoke. One garden club recently received a grant that will help pay for signage in those gardens and other areas where sustainability efforts are underway.

Weitzenfeld also says that Roanoke is creating an integrated pesticide management plan — also a requirement of the Xerces Society to be certified as a Bee City — to rein in the use of chemicals that are detrimental to the pollinator population.

In Washington Park, the city has created a riparian buffer that will provide beneficial vegetation and access to a water source for pollinators. In Vic Thomas Park, the city has created a natural meadow. A team led by Laura Riley, the city’s landscape management coordinator, has removed invasive species there and is in the process of planting native flowers that they hope will attract more pollinators.

Virginia Western Community College in Roanoke was named a Bee Campus in July. The school hosts an arboretum that highlights native plants. Photo by Megan Schnabel.

Virginia Western Community College in Roanoke was named a Bee Campus in July. The school hosts an arboretum that highlights native plants. Photo by Megan Schnabel.

Virginia Western Community College

Virginia Western Community College in Roanoke is one of the latest colleges to become a Bee Campus. Heather Butler, an assistant professor of biology, says that the school applied with the Xerces Society in June and on July 14 was certified as a Bee Campus.

This was a logical next step, as Virginia Western had already been doing many of the things required to become certified. The Bee Campus Committee is composed of faculty, staff (including the campus police) and students, demonstrating a campus-wide commitment to the cause. Butler says that it really is a community effort and everyone is enthusiastic and looking for ways to get involved. The school also maintains a website in an ongoing effort to educate the public on the importance of protecting pollinator habitats.

Across the campus, many native trees, flowers and plants dot the landscape. This is no more evident than in the school-maintained arboretum, just off Colonial Avenue. While the arboretum features a variety of species, it has a plot specially dedicated to native plants. Butler says that the school hopes  to expand and add more plots of native plants, important to pollinators.

Butler also says that Virginia Western has remained committed to taking care of the plants and trees around campus in a responsible way. The school has used only organic pesticides to fight off destructive insects that threaten the native plants and trees.

A butterfly in the Community Arboretum at Virginia Western. Photo by Megan Schnabel.

A butterfly in the Community Arboretum at Virginia Western. Photo by Megan Schnabel.

Although honey bees are not native to North America, Virginia Western’s horticulture department has established beehives behind the tennis courts, in conjunction with Chet Bhatta, an entomologist at Radford University. Both faculty and students contribute to the upkeep of the hives, Butler says, And the college wants to add native plants around the hives to aid the bees occupying them.

“We’re really excited to get this off the ground,” she says.


The city of Salem earlier this year received a grant of $1,000 from Keep Virginia Beautiful that it plans to use to convert some of the turf grass in Longwood Park into a native working prairie, according to Jeff Ceaser, the city’s horticulturist.

“Becoming a Bee City is certainly a possibility, but the problem is that this is a long-term project,” says Ceaser.

However, Salem had been working on projects both to beautify and preserve the natural surroundings, long before receiving the grant.

Ceaser says that his crews recently removed rotted trees to incorporate trees that bear fruit such as pears. These are beneficial to pollinators because they provide a source of food. The city has also experimented with test plots to see if native grasses will grow in certain places.

In other areas, the city is letting the grass grow. Ceaser says