Here, But Functionally Gone

by Susan Laszewski
Sea otters play at Moss Landing Harbor, California.

Sea otters play at Moss Landing Harbor, California. Credit: Chuq Von Rospach

Extinction. The end of a species; no coming back. Many conservation efforts strive to save species from this fate, and a species’ risk of extinction can also be a major factor in determining its listing as endangered.

A recent study published in Nature suggests, though, that we may want to pay a bit more attention to something called “functional extinction” — the point at which a species has too few members to continue filling its ecological role, even though it may still have a way to go until traditional “numerical extinction.”

Researchers at Linköping University in Sweden ran a number of analytical models to determine how often and in what circumstances functional extinctions occur. They found that larger animals are more likely to become functionally extinct, often driving smaller animals in a food web to numerical distinction. What’s more, this functional extinction can occur following a population decline of as little as 30 percent, meaning that a species only has to lose a third of its members before other plants and animals in the same food web may start to disappear.


A decline in cougars in Zion National Park in the first part of the 20th century led to an increase in the mule deer population and subsequent threat to cottonwoods and other vegetation. Credit: Wayne Dumbleton.

The study is theoretical, relying on models rather than data and observation of any particular species. However, the authors note that this phenomenon has already been observed by other researchers in cases such as that of the sea otter. The health of the sea otter population correlates to the health of kelp forests, as sea otters keep the populations of sea urchins and others that feed on kelp in check. Since kelp forests can be an important carbon sink, declines in sea otter population can have wide ranging effects, indeed.

The study’s authors suggest that their results “lend strong support to arguments advocating a more community-oriented approach in conservation biology.” At American Forests, we strive to protect and restore ecosystems for the benefit of all of their inhabitants and maintain awareness of the state of keystone species upon whom the rest of an ecosystem depends. The whitebark pine in high elevations of the Greater Yellowstone Area, for example, is threatened by explosive populations of mountain pine beetle and other threats. Consequently, its ability to fulfill its ecological role is also compromised. As fewer whitebark pine seeds are produced, animals like grizzly bears and Clark’s nutcracker are feeling the loss. You can help us protect and restore ecosystems like these, for all of their inhabitants.

A Colorful Fall Birthday for Guadalupe Mountains National Park

by American Forests

By Lizzie Wasilewska

Guadalupe Mountains National Park, which lies on the Texas-New Mexico border, may not be a very well-known park, but it is nonetheless a fascinating and beautiful one. From a distance, it appears as a series of majestic mountains breaking up the desert landscape; close up, it reveals a range of smaller wildernesses, ranging from salt flats to glades to forests, all of which are populated with an abundance of wildlife.

McKittrick Canyon

McKittrick Canyon. Credit: Caleb Unseth

The park’s birthday — which is today — occurs during one of its most beautiful times of the year. Every fall, thousands of visitors visit the park’s McKittrick Canyon to view the turning bigtooth maples, dramatically framed by the surrounding desert and blue skies. The canyon’s spring-fed oasis creates an inviting habitat not only for the maples but for a variety of wildlife including mountain lions, wild turkeys, black bears and elk. The bigtooth maples are one of many species of trees that thrive in the park despite its harsh desert conditions. To the west, species including pinyon pine and junipers grow in lower elevations; canyon interiors are home to species including maple, ash and oak; pine and aspen grow in the alpine uplands. A variety of factors, including the springs of water that are recharged by wet uplands, contribute to the park’s diversity of plants and animals.

El Capitan

El Capitan, Guadalupe Mountains National Park. Credit: Lorraine Paulhus

In 1959, the petroleum geologist Wallace E. Pratt decided that this region deserved wider recognition and protection. He donated 4,988 acres of his ranch in McKittrick Canyon to the National Park Service, and other landowners followed suit; eventually, writers, senators, governors, and congressmen gathered together in an effort to establish the region as a national park. They were not without opposition: Many ranchers relied on the land for income and were reluctant to move on. Nonetheless, on October 15, 1966, Lyndon B. Johnson signed the establishing act, and in 1972, the park was opened to the public. Some opposition from the area’s ranching community continues to this day; their land is now used as a buffer zone that protects the fragile ecosystem of this park.

American Forests recognizes the importance of the role that local communities play in protecting ecosystems, which is why we work with local partners on our tree planting and restoration efforts. The efforts of local communities help to ensure bright futures for ecosystems like Guadalupe Mountains National Park.

Fighting Fire with Fire

by American Forests

By Marcelene Sutter

The Rim Fire in the Stanislaus National Forest

The Rim Fire in the Stanislaus National Forest in California, which killed patches of forests thousands of acres in size. Many trees destroyed in this fire were the types of big trees that this study has discovered are vital for wildfire management. Credit: U.S. Department of Agriculture

In a recent paper published in Science, leading fire scientists in the West propose a solution to address the sweeping and highly destructive wildfires that have ravaged the region in recent years: more fire. The authors, including top scientists from the University of California, Berkeley, the University of Washington, Colorado State University and the University of Arizona, stated that “fire policy that focuses on suppression only delays the inevitable, promising more dangerous and destructive future forest fires.” In the past, conventional wisdom in wildfire prevention tactics held that suppression of fire is the most effective tool in fighting fires, but this paper states that the effect that climate change has on forests should be reflected in new fire policy. The proposed changes to fire policy in this paper include the use of more controlled burns as a method of reducing fuel levels in forests.

A prescribed burn at Fort A.P. Hill, Va.

A prescribed burn at Fort A.P. Hill, which has one of the largest prescribed burn programs in Virginia. Prescribed burning is conducted to increase maneuverability, reduce fuel loads, improve wildlife habitat, and maintain fire-dependent vegetation communities. Credit: U.S. Army Environmental Command

Previous  fire suppression policies  have contributed to more destructive fires in the region. The regrowth and fuel buildup resulting from these campaigns, coupled with the timber harvesting that removed many larger and more fire-resistant trees, has changed the forested landscape in the West. As rising temperatures lead to a longer fire season, these forests are more vulnerable. A chief concern expressed by the authors of the paper is that severe fires will disturb large enough areas of the conifers that have adapted to frequent forest fires, causing the loss of the seed bank, thereby thwarting forest regeneration. This would lead to more permanent changes to forest makeup as these areas would become shrub fields as opposed to robust forests.

The prescribed burn method has been used at several national forests with remote wilderness areas across the country, but has been hindered in California, where air quality regulations and threat posed to neighboring communities has many concerned with this method. In this case, the authors concede that, with the careful preservation of bigger trees, mechanical thinning to weed out the smaller, denser tree growth in the region could have a similar effect as burning.

At American Forests, we recognize that large, intense, destructive wildfires pose a serious threat to forests, which is why we have several Global ReLeaf campaigns focused on the restoration of areas affected by such wildfires, including Alpine County, California, which was affected by the 2011 Airport Fire. To learn more about the Airport Fire Planting or any of our Global ReLeaf campaigns, visit the Global ReLeaf section of the American Forests website.

Walk to School and Walk for Health

by Susan Laszewski
Walking to school

Walking to school. Credit: pawpaw67/Flickr

Did you or your little ones miss International Walk to School Day yesterday? Not to worry. As the occasion has gained popularity in recent years, the International Walk to School Committee expanded it in 2010 to make the entire month of October Walk to School Month.

Of course, there are many reasons why it’s not feasible for everyone to let their child walk to school. But, if you do live in an area where your kids might be able to skip the school bus, just think about some of the many benefits they, the rest of your family and your community stand to gain: exercise, a sense of community, reduced air pollution and expense by saving the car trip to school. And, of course, a topic dear to our hearts here at American Forests — the many benefits to children of being outside in nature, including the nature that grows along the streets and sidewalks on the way to school. Research has shown that:

Walking to school.

Walking to school. Credit: Lynn Friedman

  1. Trees and other greenery help reduce symptoms of attention deficit hyperactivity disorder, or ADHD, in children.
  2. Children who can easily reach a green space have lower stress levels and lower body mass.
  3. A positive dose-response relationship exists between exercise in nature and mental health, particularly for young people.
  4. Access to nature can improve creative problem-solving abilities.

But these benefits don’t have to stop once the walk to school is over. Having trees around at recess — or even just being able to see some nature from the classroom window — can have positive effects. That’s why our Community ReLeaf project in Atlanta has been looking at the city’s urban forest around schools to calculate the benefits they provide to students and schools. On October 24, we’ll begin the restoration phase of the project, planting trees near schools for healthier environments for youth and the larger community.

For more ideas about how to participate in International Walk to School Month, visit them on the web.

Self-healing for Forests

by American Forests

By Lizzie Wasilewska

lush forest

Lush forest. Credit: Sam Agnew

Forest recovery is an incredibly complex and frequently unpredictable process. It often requires outside help, but there are also ways in which forests heal themselves. Researchers recently discovered that nitrogen — a chemical that plays a major role in the formation of cells in many organisms — is crucial to trees’ ability to recover from environmental damage; with sufficient nitrogen, damaged forest ecosystems can heal with surprising speed and fullness.

For their study, published last month in Nature, the researchers began by selecting forest plots that had been damaged by agricultural use in recent decades. They compared these forests to mature forests — each around 300 years old — from the same area. Their results show that forests have an amazing capacity for regrowth after damage. The young trees in their study accumulated biomass quickly, and on a broad scale, the forests recovered with surprising rapidity.

Montverde Cloud Forest

Montverde Cloud Forest. Credit: Andrew Hall

Nitrogen plays a central role in their recovery process; the younger and quickly recovering trees have especially high nitrogen demand. In an interview with, researcher Sarah Batterman said, “We found that during the period when forests are recovering rapidly, typically in the first few decades, they have a really high nitrogen demand.” According to the study, after about 12 years, the forests’ reliance on nitrogen rapidly declined as their overall health increased.

The results have important implications for climate change, since the ability of forests to heal themselves also means that they can more effectively synthesize carbon dioxide, which in turn allows forests to better moderate global temperatures.

But faced with a climate changing more rapidly than many forests can adapt to, the ability of forests to heal themselves is threatened. In 2009, American Forests co-chaired a Climate Change Work Group in order to develop effective strategies for aiding forest restoration, including climate change mitigation and adaptation strategies. This is one of several ways in which American Forests contributes to discussions of climate change and forests More information can be found here.

European Ash to Ashes?

by American Forests

By Marcelene Sutter

European ash, which faces serious threats from fungal infections and emerald ash borers. Credit: Alois Staudacher

Eurpoean ash, which faces serious threats from fungal infections and emerald ash borers. Credit: Alois Staudacher

European ash trees cannot seem to catch a break. Currently, an ash dieback fungus caused by Chalara faxinea has been plaguing Europe, requiring research funds and the efforts and attention of scientists. Now, another threat to these trees looms on the horizon. As readers of American Forests magazine know from the Winter 2013 issue, the emerald ash borer has been monumentally destructive to ash trees in North America. The beetle, native to Asia and eastern Russia, killed almost all of the North American ash trees that it has infested since it entered the country in 2002, but scientists recently discovered that the voracious insect is not finished yet. Emerald ash borers were recently found in Moscow, and scientists believe that they are spreading to Europe.

The current focus of ash tree research in Europe is on finding ash trees that are tolerant or resistant to the fungus outbreak, but Dr. Steve Woodward, a tree pathologist from the University of Aberdeen, says that this approach may not be wholly effective, stating that “the problem with then jumping on [resistance to Chalara] as though it’s a great solution to the problem of ash and the loss of ash is that … it’s highly, highly likely that they will still remain highly susceptible to the emerald ash borer.” Between fungal infection and the imminent threat of the emerald ash borer, the ash trees commonly growing across Europe are seriously threatened.


Emerald ash borer. Credit: U.S. Department of Agriculture

The health of ash trees in North America and Europe contrasts sharply with that of Manchurian ash trees throughout Asia, where both of these threats originated. Scientists believe that this peaceful co-existence is due to co-evolution. Because both the Chalara fungus and the beetles are imported threats to American and European ashes, the trees have not had the chance to evolve the same defenses as Asian Manchurian ash trees. For this reason, scientists feel that the Manchurian ash could provide clues in the quest to develop resistance to both of these threats.

To learn more about the destructive effects of the emerald ash borer in Dr. Deborah G. McCullough’s article featured in American Forests or learn how to take action against the emerald ash borer.

The Rise and Fall of Champions

by Susan Laszewski

Relative to humans, most tree species live a long time. Many of the trees we have personal connections to have been around long before us; some of the oldest trees have been here longer than the pyramids of Giza, perhaps even longer than Stonehenge.

champion red hickory

Champion red hickory in Summit, Ohio. Credit: Ohio Big Tree Program

It might seem like we couldn’t possibly watch these giants rise and fall during our puny lifetimes, but that’s exactly what the National Register of Big Trees does. And you may be surprised how much the pot is stirred twice each year when the register is released. New champions are crowned, others are dethroned and ties are broken.

That’s why this is one of our favorite times of year here at American Forests, where October means not just cooler weather, crisp apples and changing colors, but also the release of the fall edition of the National Register of Big Trees.

The latest edition of the register recognizes more than 780 national champions, and more than 40 of them are wearing their crown for the first time, including 11 in New York, five in Oregon and one in the District of Columbia, where the trees continue to grow even as parks are shuttered.

The latest release of the register even includes a new mega-tree — a tree with 650 points or more, the largest of the large. With 724 points, Oregon’s California-laurel joins just 14 other trees in this elite group.

Where is the champion of your favorite tree species? What national champions call your state home? You can find the answers to these questions and more by searching the register. And, if these champions inspire you to get more involved in the effort to find, document and protect big trees, you might consider hunting for big trees yourself. There are still 200 species without any representation on the register. Visit our Big Tree section to learn more about how you can nominate trees.

It’s World Animal Day

by American Forests

By Lizzie Wasilewska

On October 4, 1931, a group of Italian ecologists founded World Animal Day with the hope of drawing attention to threatened wildlife. They selected this date because it is the feast day of Francis of Assisi, a patron saint of animals. Since 1931,

Broad Winged Hawk

Broad-winged hawk. Credit: Jerry Oldenettel

people of many religions and nationalities have adopted this day as an opportunity to celebrate animal life: special events are held all over the globe in order to appreciate the countless amazing animals of the world and raise awareness about threatened species.

American Forests celebrates World Animal Day by supporting biodiversity through restoration projects around the world. Recent animal species that our projects have benefited include the red-cockaded woodpecker, the marvelous spatuletail hummingbird, and the Northern spotted owl, among many others. Recently, we helped restore forests in Veracruz, Mexico, that are critical to an amazing number of migratory and resident bird species: 67 percent of the 341 migratory species listed by the U.S. Fish and Wildlife Service rest in Veracruz during their migrations. While this is one of the most diverse ecosystems in Mexico, it is also one of the most vulnerable. Since 2010, American Forests has supported this fragile ecosystem through education projects and planting trees: Last year, we planted tens of thousands of trees in the Veracruz highlands. These trees will provide crucial habitats for many migratory birds.

Tropical Forest

Tropical Forest. Credit: Will Chen

One of the migratory bird species that is common in Veracruz is the broad-winged hawk. Certain subspecies of the broad-winged hawk fly in flocks of hundreds of thousands. During their fall migrations, they can travel about 62 miles a day, with a rest in Veracruz on their roughly 70 day trip to South America. Populations of the broad-winged hawk are fairly stable, but due to the effects of forest fragmentation, they are declining.

World Animal Day is a time to celebrate fascinating animals like these, and continue to make our best effort to ensure the protection of their habitats.

The Serious Business of Leaf Peeping

by American Forests

By Marcelene Sutter

Fall foliage in different stages of the color change cycle in Wilmington, Vermont.

Fall foliage in different stages of the color change cycle in Wilmington, Vermont. Credit: Kimberly Vardeman

At some point in your life, someone has probably informed you that money does not grow on trees, and while this oft-stated truism does make a lot of sense, Megan Smith, Vermont’s commissioner of Tourism and Marketing, heartily disagrees. “I’d like to say that money falls from trees at this time of year,” Smith stated last week in an interview with NPR. What she is referring to is the lucrative business of “leaf peeping” in her state, which draws crowds of more than five times Vermont’s population every year.  These tourists come to Vermont for two purposes: to photograph leaves and to spend money, to the tune of $460 million annually.

These expenditures have made foliage tourism a booming and very competitive business, as Vermont must compete with other states to draw tourists to its trees. This has resulted in the creation of an interesting new job for Michael Snyder, Vermont’s commissioner of Forests, Parks and Recreation: leaf forecaster. Although the title is unofficial, the work is serious business. Snyder is responsible for scouting missions conducted on the back roads of Vermont’s densest forests looking for signs of color change in the foliage. Snyder describes his work as “part science, part guesswork,” as these kinds of predictions come from knowledge of the trees and the conditions that they are exposed to along with examination of early color-turning.

The Hapgood Pond Recreation Area on the Green Mountain National Forest displays its fall foliage.

The Hapgood Pond Recreation Area on the Green Mountain National Forest displays its fall foliage. Credit: U.S. Department of Agriculture.

As beautiful as these trees are, they are also extremely important to the ecosystems of the forests they inhabit. When Hurricane Irene hit in 2011, the riparian tree population in the White River area of the Green Mountain National Forest in Vermont was decimated. This was a severe detriment to the health of the watershed and the aquatic species in the region because, without trees to provide shade, water temperatures rose to levels too high to be healthy living conditions for fish. For this reason, American Forests has made tree planting in the Green Mountain region a part of the Global ReLeaf campaign. To read more about the riparian tree planting project, check out this article, which appeared in the Fall 2013 edition of American Forests magazine.

Divided and Disappearing

by Susan Laszewski

It’s well known that when habitat becomes fragmented, wildlife suffers. But now, a study more than two decades in the making has published its findings in Science demonstrating just how rapidly mammals species disappear in fragmented patches of forest.

The study found that mammal species whose habitat becomes fragmented can disappear in as little as 25 years.

Chiew Larn resevoir in Thailand

Chiew Larn resevoir in Thailand. Credit: kandyjaxx/Flickr

When the Chiew Larn reservoir was created in 1987 by damming the Khlong Saeng in Thailand, it flooded the forest valley, creating multiple small islands of fragmented habitat where there had once been a large expanse of continuous forest. A team of researchers led by David Woodruff of the University of California at San Diego recognized the perfect opportunity to study the effects of habitat fragmentation on species. In the early 1990s, they trapped, tagged and released a diversity of animals on 12 of the islands. They did the same in the intact forest surrounding the reservoir. On the smallest islands — those less than 24 acres — they observed extinctions in as little as five years.

Last year, biologist Dr. Luke Gibson of the National University of Singapore returned to the very spot where Woodruff and the team had gathered their data decades earlier. The decline in biodiversity in that short time was stunning. Where Woodruff’s team had tagged between 7 and 12 species of mammal on most of the small islands, Gibson could find only one or two remaining. In contrast, he found no change in the mainland forest.

Chiew Larn resevoir

Patches of fragmented forest scattered in the Chiew Larn resevoir. Credit: stoleng/Flickr

Complicating matters further, is that one of the mammal species found on the islands — on some islands, the only mammal left — is the Malayan field rat, an invasive species. According to the study, “such biotic invasions are becoming increasingly common in human-modified landscapes.”

Forest habitats are becoming more and more fragmented around the world. Around 90 percent of South America’s Atlantic forest, home to the golden lion tamarin covered in Loose Leaf earlier this week, is destroyed, with the remainder mostly in fragmented patches of less than 200 acres.

And it’s not only tropical forests that are suffering from fragmentation. American Forests Global ReLeaf has worked to create wildlife corridors to connect fragmented habitat for Mexican spotted owls in Angeles National Forest, ocelot in the Lower Rio Grande National Wildlife Refuge and a variety of native species in Exeter, England, among many other projects.