Putting Pheromones to Work

by Susan Laszewski

You might expect to find a blog post about how to use pheromones to their full potential on a dating blog, but we’re not talking about human pheromones. We’re talking about beetles.

A close-up of a mountain pine beetle.

A close-up of a mountain pine beetle. Credit: Ward Strong, B.C. Ministry of Forests, Lands, and Natural Resource Operations / Simon Fraser University Public Affairs and Media Relations

At American Forests, we’ve been using a synthetic version of the pheromone verbenone to repel the destructive mountain pine beetle from whitebark pine. The verbenone patches mimic that which the beetles give off to communicate to other beetles that the tree is full. “No room — find your own tree,” the pheromones say. By arming healthy trees that are most likely to survive other threats with verbenone patches, we can help give the whitebark pine population a fighting chance against the mountain pine beetle.

But there’s another way that pheromones can be used to help forests under siege by these beetles. They don’t just repel — they also attract. Researchers from the University of Alberta are developing a bait to monitor the beetles’ activity in Canadian jack pine forests. By using pheromones to attract the beetles to “trap trees,” the beetle population can be concentrated to a limited number of trees. Then, those trees — and the beetles along with them — can be removed, sparing the surrounding trees from attack.

Studying the concentration of beetles on trap trees can also tell us more about their population in different areas. This could help managers make decisions about priority areas for containing what lead researcher Dr. Nadir Erbilgin calls “the most damaging insect in North America.”

Though baits of this kind have been used in lodgepole pine forests before, this study is investigating their use with jack pine — a tree that, until recently, was not believed to support the mountain pine beetle. But, as the beetle population explodes across the Western U.S., they’re increasingly attacking jack pine — and whitebark pine. Whitebark pine lives at elevations in which the beetles previously ventured rarely and died during winter. As winters warm up, the beetles are getting more and more comfortable — and living longer — at higher elevations. Their attack on the whitebark pine population is having cascading effects throughout ecosystems like the Greater Yellowstone Area.

The study on jack pine bait was published last month in New Phytologist and the researchers’ field trials in the jack pine forests will continue through the summer. In the meantime, you can help us with our work repelling the beetles from healthy whitebark pine trees by supporting our Endangered Western Forests initiative. Let’s arm our forests with the tools to fight off North America’s “most damaging insect.”

A Tree and a Recipe

by American Forests

By Lisa Swann

Harvested black walnuts

Harvested black walnuts. Credit: knitting iris/Flickr

Found from the Great Plains eastward and from Georgia to Massachusetts, the black walnut tree prefers rich floodplain soil and usually associates with other hardwoods such as maple, elm and sycamore.  Considered somewhat rare, its wood is used for furniture and gun stock. Some thieves have caught on to its value and have posed as arborists and made off with a tree! Growing a full, mature black walnut can take 60 years and a 200-year old tree can fetch tens of thousands of dollars. The story of how this wild crop goes from the forest to your table is told in the American Forests magazine article, “A Wild Crop and Backyard Harvest.” But how does the walnut’s story continue once it arrives in your kitchen?

Fortunately for black walnut lovers, harvest comes in October — right before Thanksgiving. You can substitute black walnuts in many foods that call for English walnuts. There are many recipes for black walnuts, including this simple one for black walnut pie:

Easy Black Walnut Pie

Black walnut pie

Black walnut pie. Credit: buttersweet/Flickr

  • 1 unbaked 9-inch pastry shell
  • 1 cup light corn syrup
  • 1/2 cup packed brown sugar
  • 1/2 cup sugar
  • 3 tablespoons butter
  • 3 eggs, lightly beaten
  • 1 cup chopped black walnuts


  1. Bring the corn syrup, brown sugar and regular sugar to a boil in a saucepan.
  2. Just when it boils, remove from heat.
  3. Stir in the 3 tablespoons of butter and let it cool for three minutes.
  4. Stir lightly beaten eggs into the mixture, add walnuts and stir well.
  5. Pour into the pastry shell. Bake at 325° for 55-60 minutes or until top is browned.

Makes 8 servings.

Read more about black walnut harvesting.

The True Cost of Forest Fires

by American Forests

By Marcelene Sutter

A firefighter combats a dangerous blaze in the Rim Fire in the Stanislaus National Forest

A firefighter combats a dangerous blaze in the Rim Fire in the Stanislaus National Forest in August, 2013. Credit: US Department of Agriculture

As the world warms up, the struggle to raise the money to fight increasingly intense and more frequent forest fires continues. The rise in temperatures is causing trees to dry out, and fire-prone areas are already feeling the effects. Wildfires are burning stronger and longer, and the government is struggling to provide the funds to fight back. These fires have become a nightmare both for the officials struggling to find the funds to fight them as well as for the firefighters who work tirelessly to fight blazes that are burning more intensely than before.

The increasing threat of forest fires is directly reflected in the capital needed to fight them; before 1999, there was not a need to spend more than $1 billion per year on fire suppression, but since 2000, the budget for such efforts has been forced to steadily rise due to demand, and has topped $1.5 billion multiple times since 2006. This is a double-edged sword for the Forest Service, which is forced into “fire borrowing,” — taking funds from other programs to combat the fires that are destroying millions of acres of forests while simultaneously consuming millions of dollars. While these fires do need to be fought, this appropriation of funds takes away from other vital operations, such as reforestation efforts and research into new firefighting strategies, which work to reverse the negative effects of these devastating fires.

A new solution is being sought by policy makers, and Secretary of Agriculture Tom Vilsack said at an event in Fort Collins, Colo., in July that “…lightning strikes that start forest fires are treated differently from a funding perspective than hurricanes and tornadoes and other natural disasters. We think there should be greater alignment.” Congress included increased funding to fight wildfires in the Continuing Appropriations Act that ended the shutdown, but the struggle is still not over. At American Forests, we recognize the paramount challenge that forest fires present to forest health. To learn more about how we work to restore ecosystems damaged by fire, check out our work on Forests and Fire. To help, write to your representative asking them to support the Collaborative Forest Landscape Restoration Program, which facilitates the reduction of wildfire management costs.

Good News for the Bay

by Susan Laszewski
Chesapeake Bay.

Chesapeake Bay. Credit: Forsaken Fotos/Flickr

In the 23 years since amendments to the Clean Air Act imposed regulations on emissions of nitrogen oxide from power plants, nitrogen deposits in nine Chesapeake Bay area watersheds have declined 34 percent, according to a new study from the University of Maryland Center for Environmental Science, published last month in Environmental Science and Technology. The study’s lead author, Dr. Keith N. Eshleman, tells the Baltimore Sun that the reduced air pollution’s effect on the water was a surprise to the researchers. “Here the Clean Air Act has caused something to happen that’s wonderful and good news and completely unanticipated,” he says.

American Forests has been working toward the health of the Chesapeake Bay area through our Global ReLeaf program — establishing forested buffers along the banks of the James River and working with Delmarva Poultry to create buffer zones that would protect the Bay from the poultry industry’s pollution — so this is good news indeed. Here’s to continuing improved health for this important watershed.

105 Years of Zion National Park

by American Forests

By Lisa Swann

Zion National Park

Zion National Park. Credit: National Park Service

Zion National Park in southwestern Utah is celebrating its 105th anniversary tomorrow, and there is a lot to celebrate! With deep, sandstone canyons, pinyon-juniper and conifer woodlands, hanging gardens and waterfalls, the park is a delight to visitors. Some 207 types of birds can be found in the park. This rich tapestry of habitats and species make it one of the most visited sites in Utah.

The park includes Horse Ranch Mountain, at 8,726 feet and desert, riparian and woodland communities and neighbors the Mojave Desert, the Great Basin and the Rocky Mountains. One of the more unique features within Zion National Park’s 229 square miles is a series of narrow sandstone canyons.

More than 1,000 species of plants can be found in the park, from tall cottonwoods growing along the river to towering pines and firs shading the higher elevations. Some plants in the park, such as prickly pears, cholla and yucca are adapted to the desert climate. In the hanging gardens, one can find colorful Zion shooting-stars, scarlet monkey flowers, and Western and golden columbines.

A variety of wildlife find food, shelter and nesting places in Zion. From the Endangered Species list, California condors fly above the cliffs of the park. Zion’s canyons are also home to the highest density of the threatened Mexican spotted owl — a species whose habitat American Forest has been restoring in New Mexico through our Trigo Reforestation Global ReLeaf project. But that’s not all. The park is home to approximately 67 species of mammals, 29 species of reptiles, seven species of amphibians, and nine species of fish. For all their sakes, we wish Zion National Park a very happy birthday.

Trout in Trouble

by American Forests

By Marcelene Sutter

Fishing is a fond memory for many of us, whether you spent childhood summers fishing with friends, or enjoy bonding with your children or grandchildren on fishing trips. Fishing for many in the American West means one thing: trout. The trout is iconic in this region, especially in Montana, where the cutthroat trout is the official state fish. The trout, native to the American West and prized by fisherman for its mild, earthy taste and by state governments for the income it generates (about $250 million per year in Montana alone), finds itself seriously threatened by climate change.

Cutthroat trout, the state fish of Montana. Credit: USFWS Mountain Prairie.

Climate change has not only warmed the water in the streams where the trout lives, but also caused droughts and reduced snow in the winter, negatively affecting water flow in the spring, making it harder for trout to move. In order to better understand the specific effects that climate change is having on trout in the west, scientists are using electric currents to catch and, subsequently, track the cutthroat trout, native to the northern Rockies region of Montana, with small transmitters known as pit tags. Brad Shepard of the Wildlife Conservation Society explains that the electric current is used as an attraction device to make the fish easier to net, telling NPR that the current “actually draws fish.” Scientists catch the fish, insert the trackers and release the trout back into the streams, beginning a years-long tracking process. Finding these trackers sometimes takes scientists off the beaten track; they have been found anywhere from marten dens to the freezers of local fishermen. Scientists are looking to follow the lives of these fish, determining growth and mortality rates, as well as time and cause of death. This data is collected and analyzed to determine any correlation to changes in stream flow and water temperature, to see if these factors affect the trout in a significant way. These factors really affect the trout, cueing “when they spawn, when they hatch, when they emerge, when they come out, how fast they grow, where they go,” as Shepard tells NPR. “But as you shift things in one direction, you can, in fact, lose part of the population.”

It will take time to fully understand the effects that lessened stream flow and higher water temperature have on cutthroat trout, but early emerging trends suggest that non-native fish, such as the rainbow trout, are moving further upstream, which previously was too cold for that species, into the cutthroat trout’s range. As the two trout species mix, rapid hybridization occurs, resulting in a marked decrease in trout fitness. This new, weaker trout becomes prey for fish, such as bass, which are moving into trout habitat that was once too cold for them. Climate change poses and new and serious threat to this iconic fish of the American West, and measures must be taken now, at the first sign of trouble to ensure its survival.

Lessons Learned: The Need for Future Research on Urban Forests

by American Forests

By Maria Harwood

National Academy of Sciences

At the National Academy of Sciences. Credit: Amber Case

Earlier this year, our director of Urban Forest Programs, Melinda Housholder, attended a workshop hosted by the National Academy of Sciences titled “Urban Forestry: Toward an Ecosystem Services Research Agenda” and blogged about a few of the presentations she was able to attend.

Recently, the workshop summary was published online, free to download as a PDF, detailing not only the individual presentations, but also the necessary next steps to further our understanding of urban forests and their associated ecosystem benefits.

It was determined that the key mechanisms behind ecosystem functions need to continue to be explored, so we can develop a more in-depth understanding of the role urban forests play within an urban ecosystem. Currently, the state of our research on the topic is quite limited and does not fully allow blanket statements about the ecological benefits of urban trees to be extended across varied landscapes.

Our expanding knowledge of urban forests must address these gaps in order to demonstrate the value of urban tree plantings as a tool in attaining state air and water quality goals. Similarly, proponents of implementing green infrastructure to address stormwater management issues are advocating for legislation that will promote further research on the techniques, as well as encouraging the EPA to integrate green infrastructure technologies into their regulatory programs.

The need for future research on urban forests is great, but it shouldn’t be overwhelming. While key research has already been conducted to form the framework of our understanding of urban forest ecosystem services — including air and water quality, heat island mitigation, wildlife habitat, and carbon sequestration — we now need to take these lessons learned and continue expanding upon them to better maximize our understanding of our urban forests’ potential into the future.

Help for Witness Trees

by Susan Laszewski
Hemlock grove at the Flight 93 National Memorial

Hemlock grove at the Flight 93 National Memorial.
Credit: James O’Guinn

Trees stand witness to many significant historical moments, often taking on a symbolism of resilience and hope. The witness trees that stand at the Flight 93 National Memorial are such trees. Managed by the National Park Service, this grove of hemlocks is the spot into which Flight 93 crashed on September 11, 2001, when crew and passengers aboard the aircraft thwarted al-Qaeda hijackers’ attempt to crash the plane into the U.S. Capitol Building.

hemlock woolly adelgid

Hemlock woolly adelgid egg sacs. Credit: Sloan Poe

Now, those trees that stood witness to a tragic occasion and have come to stand in memoriam to the brave crew and passengers of Flight 93 are under siege by an invasive insect. Hemlock woolly adelgid, most easily spotted by its white egg sacs, is currently present in about half of the Eastern hemlock’s range, in states from Georgia to Maine, and could spread further north.

The National Park Service announced last week that they are taking action to try to prevent the further spread of the insect among the witness trees. The project will include several methods of treatment, including soil-buried tablets, soil injection, tree injection, bark spray and horticultural oil spray. Many young seedlings and saplings and 1,351 mature trees will undergo treatment.

Learn more about the witness trees and Flight 93 National Memorial at the National Park Service website. To learn more about hemlock woolly adelgid, read the American Forests magazine feature, “The Last of the Giants,” by Will Blozan.

The People’s Tree

by American Forests

By Lisa Swann

The 88-foot Engelmann spruce selected as the 2013 Capitol Christmas Tree is
hoisted onto a flatbed truck, where it will be secured for the 5,000-foot journey
across the country. (U.S. Forest Service photo)

More than 300 people gathered recently in 25-degree weather to witness the harvesting of the 88-foot 2013 Capitol Christmas Tree from the Colville National Forest in northeastern Washington State, the first step in its 5,000 mile journey to the U.S. Capitol in Washington, D.C.

It took more than a dozen equipment operators and spotters to place the tree into position on a Mack Truck. A few extra feet of trunk had to be cut to make it fit.

The Engelmann spruce — also known as white spruce, mountain spruce or silver spruce — is native to western North America and is mostly a high altitude mountain tree, growing at 900-3650 meters above sea level.

The Capitol Christmas tree is lit each year on the U.S. Capitol grounds by the Speaker of the House. It will hold nearly 10,000 lights, but will first make appearances during its trip in Ogden, Spanish Fork and St. George, Utah; Sedona and Flagstaff, Ariz.; Albuquerque, N.M.; Amarillo and Dallas, Texas; Little Rock, Ark,; Nashville, and Knoxville, Tenn.; Roanoke, Va.; Hagerstown, Md.; and Allentown, Penn. If you want to track the tree as it moves across the country, check out capitolchristmastree.com.

The tree — known as the “People’s Tree” because it comes from public land — will arrive at Andrews Air Force base in Maryland on November 24th and will be paraded into Washington, D.C. the next day.

The Elf of Plants

by Loose Leaf Contributor

Credit: Tom Jutte

The mushroom is the elf of plants,
At evening it is not;
At morning in a truffled hut
It stops upon a spot

As if it tarried always;
And yet its whole career
Is shorter than a snake’s delay,
And fleeter than a tare.

‘T is vegetation’s juggler,
The germ of alibi;
Doth like a bubble antedate,
And like a bubble hie.

I feel as if the grass were pleased
To have it intermit;
The surreptitious scion
Of summer’s circumspect.

Had nature any outcast face,
Could she a son contemn,
Had nature an Iscariot,
That mushroom, — it is him.

-Emily Dickinson

From: The Poems of Emily Dickinson: Series Two. 1896. Boston, MA: Roberts Brothers.