IN THE FIELD

Cottrell-Baldwin Environmental Lecture Series

The Cottrell-Baldwin Environmental Lecture Series, sponsored by the Forest Society and the NH Division of Forests and Lands, will be held at the Baldwin Environmental Center at Fox Forest in Hillsborough. The popular late-winter series celebrates the environmental and scholarly legacy of Annette and Bill Cottrell and State Research Forester, Henry I. Baldwin. For more information, visit forestsociety.org/cottrellbaldwin. TUESDAY, MARCH 15 | 78:30 P.M. Humans and Nature in the Monadnock Region: The First 12,000 Years

Speaker: Dr. Robert Goodby, Professor of Anthropology at Franklin Pierce University Native Americans have lived in the Monadnock Region for 13,000 years. Archaeological evidence from sites in Swanzey, Peterborough, Hinsdale, and Keene reflect their use of a broad range of terrestrial and aquatic animals, c. 5,000–700 years before present. Archaeological data reveals Native use of the landscape and natural resources, highlighting settlement patterns, seasonal movements, technology, site settings, and responses to climate change. Archaeological data also contributes to an understanding of long-term patterns and changes in species range that has potential utility for modern conservation and wildlife management.

TUESDAY, MARCH 22 | 78:30 P.M. Dive into the History of Livermore Falls, New Hampshire

Speakers: Mark Doperalski, New Hampshire State Archaeologist David Truby, Review and Compliance Archaeologist for the State of New Hampshire Join New Hampshire’s Department of Natural and Cultural Resources archaeology team to learn the details of the archeological discoveries at Livermore Falls State Forest in Plymouth. This area was initially excavated to investigate post-contact archaeological deposits associated with the nineteenth and twentieth century industrial complex and associated residential occupation known as “The Hollow. ” During their excavations, however, a somewhat substantial pre-contact Native American archaeological deposit was also identified, including the discovery of a fire hearth radiocarbon dated to roughly 3,000 years ago. Learn the fascinating details of the site and how the archaeologists uncovered heretofore unknown history at Livermore Falls. TUESDAY, MARCH 29 | 78:30 P.M. Up for Grabs! Timber Pirates, Lumber Barons, and the Battles Over Maine’s Public Lands

Speaker: Thomas Urquhart, Author and Former Director of Maine Audubon The origin of Maine’s Public Reserved Lands goes back to the 1780s when Maine was a part of Massachusetts. As a state, Maine continued the Commonwealth’s policy of reserving a “public lot” in every township sold off from its public domain. These lots (1000 acres each) were to serve the future needs, especially religious and educational, of the town. They could not be sold. When wildland townships remained unsettled, the state could only sell the rights to cut the timber on the public lots. Lumber interests (and subsequently paper companies) bought the rights and managed the land as if it was their own. A century later, after a ten-year legal struggle, Maine recovered the public lots. They are now the core of its magnificent Public Reserved Lands, managed for timber, wildlife, and recreation. Join us to learn the story of how these tracts were re-acquired.

TUESDAY, APRIL 5 | 78:30 P.M. Allagash: New England’s Wild River

Speakers: Tim Caverly, Maine author and retired ranger, and his wife Susan Join us for a presentation that includes music as well as scenic and historic photos from Maine’s northern forest. Spectators will virtually canoe the world-famous Allagash River, discover forgotten logging history, and learn about Native American archaeology. Narrated by former supervisor of the Allagash Wilderness Waterway, Tim Caverly, and his wife Susan, participants will hear first-hand about the lore, legends, and colorful characters that Tim experienced during his 32 years working as a Maine park ranger.

Consulting Foresters

The Forest Society encourages landowners to consult with a licensed forester before undertaking land management activities. The following are paid advertisers. Calhoun & Corwin Forestry, LLC

Realize what you value the most in your forest. Serving individual, municipal, state, non-government, and industry forest owners. 41 Pine St., Peterborough, NH 03458 • 603-562-5620 Email: swiftcorwin@gmail.com

FORECO: Forest Resource Consultants

Complete forest management services Offering three licensed foresters, licensed land surveyor P.O. Box 597, Rumney, NH 03266 • 603-786-9544 P.O. Box 161, Contoocook, NH 03229 • 603-746-4846 Email: office@forecollc.com

Full Circle Forestry, LLC Jeffrey Snitkin NHLPF #452 802-310-0292 • jsnitkin.fcf@gmail.com Ehrhard Frost, NHLPF #103 802-785-4749 • efrost.fcf@gmail.com Eric Radlof, NHLPF #447 603-321-8249 • eradlof.fcf@gmail.com

Providing a full range of ecologically based and economically practical forestry services to landowners that share a long-term stewardship vision for their forest. -NRCS Technical Service Provider, Tree Farm Inspector 752 Rt. 103A Newbury, NH 03255 • 802-310-0292

Martin Forestry Consulting, LLC

Offering complete forest management services including timber sales, cruises, and appraisals and wildlife habitat management. P.O. Box 89, New Hampton, NH 03256 • 603-744-9484 Email: martinforestry@gmail.com

Meadowsend Consulting Company

Quality Consulting Forestry with Integrity. Guaranteed. Jeremy Turner, NHLPF #318 — Southern NH jturner@meadowsendco.com Matthias Nevins, NHLPF #518 — Central NH mnevins@meadowsendco.com Ryan Kilborn, NHLPF #442 — Northern NH rkilborn@meadowsendco.com

Vast range of quality land management services. Connect with us for a free site consultation! meadowsendco.com • 603.526.8686

Licensed foresters should address inquiries about advertising to Anne Truslow by calling 603-224-9945 or emailing atruslow@forestsociety.org.

Fever Connected

A Writer Muses About Her 1,000 Ascents of Mount Major

BY MARY ELLEN HUMPHREY

Watching sunrises from the summit of Mount Major was always a soul-stirring experience the author cherished over the course of hiking the mountain more than 1,000 times.

The nature of things is change. Hiking mountains has taught me this. Every hike is unique and special. The ambient noises, smells, and sights vary from season to season in the snow, wind, and rain. Change is inevitable.

I’ve hiked many summits over the years, including the two biggies: Mount Washington and Katahdin. Located only a half hour from my home in Rochester, N.H., Mount Major in Alton is my favorite, though. I was in my mid-fifties when I began hiking this popular mountain. For over ten years, I traversed it every chance I got—sometimes two, three, or four times a week. I often hiked the mountain twice in one day, ascending the Boulder Loop Trail, descending the Brook Trail, then up the Main Trail, and finally down the Boulder Loop Trail again. At 1,786 feet, Mount Major offers the benefits of being on a mountain trail in a more manageable way for someone of average fitness. Hiking the trails as much as I did made them easier. I didn’t have to look for trail markers or worry about what’s ahead. I already knew and was prepared. This familiarity allows for more contemplative solo hiking. While I’ll cherish the memories of hiking the mountain with friends and family, hiking solo offered me a chance to find peace and the strength to face life’s difficult problems. It’s where I learned to be grateful for the truly wonderful things in my life despite the hardships. Mount Major was where I went to sort out my thoughts, to celebrate, and sometimes to grieve.

When my son and daughter, who live in Maryland and New York, respectively, visited with their children, we always fit in a hike to “Meme’s mountain. ” My grandchildren really got what it meant to be playful in nature, relishing the wonder and delight of exploring, pretending, and imagining. They played all the way up the mountain, climbing the boulders and imagining all kinds of fun scenarios.

Hiking is a magical experience for young and old—if you tune in. Paying attention was a hallmark of Thoreau’s daily routine. He wrote, “I think that I cannot preserve my health and spirits, unless I spend four hours a day at least—and it is customarily more than that—sauntering through the woods and over the hills and fields, absolutely free from all worldly engagements. ” I couldn’t agree more. New Hampshire is blessed with natural amenities for everyone to enjoy. These special places enrich our lives and, as is often the case, we don’t grasp how special they are until it’s too late.

In 2015, a coalition of organizations, led by the Forest Society, the Lakes Region Conservation Trust, and the Belknap Range Conservation Coalition, raised more than a million dollars to conserve key parcels of land on and surrounding Mount Major. Having witnessed their stewardship of many other precious properties, I was happy the Forest Society was going to be the stewards of the mountain. With thousands of visitors each year, most of them in the summertime, you can imagine the toll it takes on Mount Major’s trails. More than 80,000 people hike it every year. Many are visitors to New Hampshire, but there are also the regulars, local folks who are drawn back time and time again to the magic of this special place. My friends and I speculated what changes might be coming to the mountain. Would hiking fees be implemented? Would the trails be changed, improved, or moved? Mostly, we were relieved that a reputable organization had taken charge of this precious real estate, protecting it from development at the very least. One of the first changes I noticed was the installation of Porta Potties—yeah!

As one hike led to another, I eventually summited the mountain more than 1,000 times before I retired and moved to New York in the fall of 2018 to be closer with my daughter and her children. During those years I hiked Mount Major, I came to feel fit, physically, mentally, emotionally, and spiritually. The mountain truly became a friend, a special place that took me beyond its physical boundaries. I learned a lot about myself and shared some truly memorable experiences with others. Here are some of my favorite memories. Above: On her sixtieth birthday, Mary Ellen and some friends hiked Mount Major to watch sunrise from the summit.

Inset: Mary Ellen and her hiking friend Art Richardson prepare to night hike Mount Major to celebrate her sixtieth birthday.

MY B-LIST EVENT

In 2012, as my sixtieth birthday approached, I wanted to do something really special—something I would never forget. Decade birthdays can be so profound, and this one weighed on my mind. How many more decade birthdays would there be? Certainly not as many as had already passed. I remember them all. Turning ten: double digits. Turning twenty: no more teenager. Turning thirty: full speed ahead. Turning forty: wait, what? Turning fifty: oh my, what now? Fifty was a hard one. I looked back and saw all of those life events; but looking ahead, I couldn’t see anything. So, I changed my life in a huge way. Now with my

On the night of the Perseid meteor shower in August 2013, Mary Ellen helped to organize a watch party from the top of Mount Major. Although clouds moved in overnight, participants were still able to see some meteors streak across the sky.

sixtieth birthday on the horizon, I could only hang on for what was next. I asked my friends to come up with some ideas for my birthday list. It wasn’t a bucket list; but rather to celebrate being alive, I wanted something really extraordinary for my sixtieth birthday experience.

The day turned out to exceed my expectations. To start, my friends accompanied me in the middle of the night to watch sunrise from atop Mount Major. I carried a thermos of tea with honey and some whole-grain cupcakes. Rain was predicted, so I thought sunrise was going to be a dud, but instead it was gorgeous. Red skies all around. After, we headed to my house for a farmer’s breakfast complete with blueberry pancakes, sausage, home fries, and scrambled eggs. Some of my friends had to head to work, but three accompanied me for the rest of the day where we ziplined at Canon Mountain and boated across Lake Winnipesaukee to have dinner at a shoreside restaurant. One of my friends came over to my house that night. It was only 8:30 when we returned, but we were exhausted. We toasted each other with a glass of champagne and called it a day.

THE PERSEID METEOR SHOWER

Have you ever watched the Perseid meteor shower? What about from a mountaintop? Well, in August 2013, a hiker friend of mine, Rex Gallagher, organized one such event atop Mount Major for 51 of his friends.

Rex made scrupulous arrangements, obtaining permission from the property owner at the time and even purchasing insurance. He invited a couple of University of New Hampshire professors to teach some geology about the mountain and the constellations in the night sky. I learned that those pits in the granite on the summit are made by lightning strikes. One formed a perfect heart shape.

It was a fabulous outing, and even though clouds moved in overnight, I saw about twenty meteors before our view was obscured. I was so happy to have spent my night exploring, listening to archeological information, learning about the night sky, and telling stories of our favorite hiking experiences. Toward the end, another hiker friend of mine, Art Richardson, and I helped shepherd some of the hikers down the mountain in the middle of the night. I think Art and I made at least four trips up and down the trail that night.

Over the years during which Mary Ellen Humphrey climbed Mount Major, she wrote poetry, including Snow, which she penned after finishing a leisurely hike of the mountain in winter. “The entire day was so magical, ” she notes. “There were these huge snowflakes drifting slowly to the ground, absorbing sounds making the world eerily quiet and peaceful. ”

Snow

I awoke to white not blue The air saturated with white flakes Falling softly, steadily, to the ground Like they have a purpose, a map to follow Determined, declining, deliberate.

The soft white comforts me Like a soft white light bulb The pace slows down It muffles, and buffers Dispenses, dissipates, defuses.

For a while, anxiety Is suspended as I am Mesmerized by the hypnotic falling flakes. The ground is covered with a soft down blanket Delicate, drifting, delicious.

I’m floating slowly to the ground My thoughts cleansed Content and calm in this quiet world, Nature’s freshly washed white linen, Distracting, distinctive, divine. On a snowy winter day in 2015, when few people were out hiking, Mary Ellen scampered up Mount Major to take photos of the magical landscape.

POETRY ON A MOUNTAINTOP

In 2014, one of my friends was looking for something different to do with her Meetup group, so I suggested they hike Mount Major. To make it even more special, we asked everyone to bring a poem to read on the summit. We called the outing Poetry on a Mountaintop. Most of the hikers brought a poem, but there was one young man who didn’t. He expressed to me that he really didn’t understand poetry. No matter how hard he tried, it wasn’t his thing.

I assured him that the best way to enjoy poetry is to not try to understand it at all, but to feel it. Just let the words be whatever they are, kind of like eating your favorite ice cream. You don’t think about how it’s made or the ingredients. You just savor the wonderful flavor.

At the summit, we assembled away from the crowd where it

was quiet. The conditions were perfect: sunny and bright with no clouds and a light breeze. After eating our picnic lunch, we began to share our poems. There was a special magic in the words of those poems, as if the mountain was part of our reading experience. Of course it was.

When we returned to the parking lot, the young man thanked me, noting that he’d never thought he’d like poetry but thought that it was really nice.

I still have one more adventure planned for Mount Major: my seventieth birthday. In July, I’ll return to New Hampshire and once more hike to my favorite summit. I’ll bring a poem, a thermos of tea with honey, and maybe some blueberry muffins. I am so excited to return! I look forward to seeing all of those special places along the trail, including the fantastic views and some of the trail improvements my hiking friend Art told me about. Will I remember every detail along the trail? I suspect it will all come back to me with every step I take.

It also looks like I’ll have quite a bit of company with me. My daughter said she and her husband and her children will join. And a few folks from where I live in New York, 11 hours away from Alton, have even said they’d like to come.

I doubt I can do a sunrise hike this time, but I plan to stay for at least a week in the area, so perhaps I can do a sunset hike before I return. My concern is that I haven’t been hiking a lot. The terrain is pretty flat where I live and I hope I’m fit enough to make it to the top without slowing others down. Oh well!

I miss Mount Major. The only reason I left is because I missed my family more. My grandchildren are growing up so fast. I wanted to be part of their lives, which is so important for families. The experience of hiking Mount Major changed me forever. It changed my way of thinking, and how I deal with life’s stresses. When I’m on the mountain, I feel so close to the power of creation, the innate wonder of our Mother Earth. I am eager to come back, as if I was returning to a childhood home where I know I belong.

Mary Ellen Humphrey, M.Ed., retired and moved to Ripley, N.Y., in 2018 to write and establish a new life near her family. She self-published My Mountain Friend: Wandering and Pondering Mount Major in 2021, a memoir about hiking Mount Major more than 1,000 times. The book is available for purchase on Amazon.

SAVE THE DATE!

Interested in making a difference at Mount Major? Join the Forest Society on Earth Day, April 22, to lend a hand picking up trash and prepping Mount Major’s trails for the summer hiking season. Visit forestsociety.org/events for more info. Above: Mary Ellen poses for a photo on the summit of Mount Major, her happy place.

The Future of Ash Trees in New England:

Looking at the research

BY STACIE HERNANDEZ

Above: The metallic green adult emerald ash borer. Top right: Bill Gould, an Abenaki artist based out of Warner, N.H., makes intricate splint baskets out of brown ash trees that he harvests in New Hampshire. Right: A white ash tree stands tall outside the home of the author.

With 84 percent of its land mass covered with trees, New Hampshire is the second-most forested state in the country. Only Maine has a greater percentage of forest cover. The Granite State has a number of valuable native hardwood trees growing in its forests, including white, green, and black ash. White ash (Fraxinus americana) and green ash (Fraxinus pennsylvanica) are commonly used for firewood and as lumber for flooring, furniture, and cabinetry. The wood from these trees is lightweight and split-resistant, two qualities that make it perfect for canoe paddles and baseball bats. Black or brown ash (Fraxinus nigra) is culturally significant to Abenaki people, who have used the wood for basket weaving for thousands of years. Naturally, the trees are an important food source and provide habitat for wildlife; and they contribute to a healthy and diverse ecosystem. But today this important natural resource is facing a severe threat.

To comprehend this threat, it’s important to understand the war trees wage with insects. Over the course of thousands of years, insect herbivores (insects that feed on plants) co-evolved with plants in their native range and reached a balance where the herbivore does not cause fatal harm to the plant host. During that time, plant defensive traits may arise, either morphological—with structures such as thorns, spines, or waxy surfaces—or through the production of compounds that deter herbivores. In response to a tree’s defense mechanisms, herbivores adapt over time by overcoming the plant’s toxins or becoming undetectable by the host. This evolution of defense and resistance, which scientists refer to as an arms race, is why these native species have been able to co-exist for centuries without mass die-off.

But what happens when a non-native herbivore sets up shop in New Hampshire? In the case of the ash tree, the results haven’t been promising. In 2002, the emerald ash borer (Agrilus planipennis), an insect native to Asia, was first detected in Michigan before it spread to many parts of the country leaving a path of destruction in its wake. These invasive herbivores have a leg up on ash in North America because the tree’s natural defenses are ineffective against them. It is feared by many that mature ash trees will be lost from our forests and along our streets, following a similar path of our once-common American Chestnut.

The Impact

As emerald ash borer (EAB) spreads across New England, foresters are adjusting their forest management plans to slow the advance of the insect. “The damage [caused by EAB] is drastic and very noticeable nearly everywhere you go in the central and eastern part of the state, ” says Steve Junkin, a field forester with the Forest Society. “My street here in Northwood has a number of ash trees growing along its sides, and there was very little sign of EAB only two or three years ago. Now, seventy percent of those ash are dead. EAB has marched into every county except Coos so far. ”

Unlike maple, hemlock, fir, and white pine, which are prominent components of our forests, ash only accounts for about 3 percent of the total trees growing in the state. This is due in part to New Hampshire’s soil, which tends to hold fewer nutrients on average than ash prefer. Ash is found to be locally abundant in sites with rich soil and plays an important ecological role in these areas.

Learn More: ASH TREE IDENTIFICATION

White ash: The leaves, leaflets, and stems are opposite. Leaves are pinnately compound with 7 leaflets. The leaflets are connected to the main leaf stem with a small stem or petiole. The underside of the leaf has a white tint. White ash bark is deeply ridged and diamond shaped. This species is typically found growing in dry soil.

Green ash: The compound leaves have 5 to 9 leaflets that have a very short petiole that the leaf tapers to. The leaf is green on both sides. The bark is somewhat flaky with shallow ridges. It can typically be found growing in floodplains and swamps.

Black ash: The compound leaves have up to 11 leaflets with serrated edges. The leaflets are sessile on the main stem (no petiole). The bark is scaly and flaking is common. It can typically be found growing in wet soils with poor drainage.

Top left: A half-inch-long adult emerald ash borer perches on top of a leaf. Bottom left: An aborist injects a systemic insecticide into the base of an ash tree to protect the tree from the borer. Top: “Ash blonding” is a common sign that a tree has been infested with borers. Small holes in the bark are also a sign that a tree is infested.

The scarcity of the species makes them hard to manage, Junkin says.

“The practice of cutting larger diameter ash trees will slow the progression of the insect, but only to a small extent, ” he says. “Starving the insect population by eliminating their food source is a practice that just isn’t feasible in New Hampshire because our forests are broken up among many different landowners who have different goals for their land. So, it’s just not practical to apply this approach on a broad scale with good results.

SHORTTERM SOLUTIONS

To maintain a healthy seed bank of ash trees for the future, the New Hampshire Division of Forest and Lands is currently treating specific sites with systemic insecticide about every three years. The agency aims to preserve a healthy genetic stock of future ash seed sources for regeneration projects by treating high-quality trees before the mature ash in our forest die off. So far, they have saved 10 to 14 ash trees at four Forest Society properties and the agency is looking to treat more in the coming years. Using a systemic insecticide is also the best short-term solution for landowners who are interested in saving exemplary ash trees in their forest.

Online:

There are 22 species of ash trees in the U.S., all of which are susceptible to EAB. The releases of biological control agents (e.g., parasitic wasps) within infestations of EAB have been occurring for over a decade in most states. To learn more about the value of these releases, visit https://bit.ly/3dh4zlx.

Recently, the Forest Society’s strategy has been to promote the regeneration of ash trees when possible. Foresters are targeting sites where ash trees tend to grow best, including places where the soils are enriched and often have sugar maple and basswood growing with the ash. “With well-timed timber harvests, these sites could be flooded with thousands of young ash seedlings, ” Junkin says. “Any mature ash left will more than likely die; however, young ash are not as susceptible to EAB attack, and with time, biocontrol insects can build their own populations allowing for a more endemic forest health condition to occur in the future. ” Currently, the Forest Society is working toward regenerating ash at Mount Monadnock Reservation in Dublin and Ashuelot River Headwaters Forest in Lempster. Junkin says Forest Society foresters will continue to monitor these regeneration locations and refine their approach as things progress.

Ash Research in New Hampshire

To effectively manage the nearly 60,000 acres the Forest Society owns, staff have provided space and opportunity for the latest scientific research to be conducted on Forest Society land in an effort to combat the devastating impacts of EAB. When the insect was first detected in Concord, N.H, in 2013, the Forest Society helped with delimiting surveys to understand how widely the newly introduced insect had spread. Samples were taken from trees within a given radius around the initial detection site and analyzed to see if they were infected. From this data, a map was developed and quarantines were set in place. Staff also performed visual surveys to observe mortality and infestation by EAB during the dormant season when there aren’t any leaves and spotting the tell-tale sign of EAB, bark blonding, is easier. Junkin says it takes EAB only 3 to 4 years to kill an ash tree if the trees aren’t treated with a systemic insecticide to protect it, so time is of the essence. Everyone from forest health experts to University of New Hampshire (UNH) graduate students to employees of the State of New Hampshire’s Forest Health Program have been monitoring the spread and studying the insect.

With Forest Society permission, UNH began a three-year research project in 2019 at some Forest Society properties, including Jennings Forest in New Durham and later at Powder Major’s Forest in Madbury. The project also took place at Lee Town Forest, a property the Forest Society holds a conservation easement on. Todd Johnson, a postdoctoral research associate who works in the lab of UNH Associate Professor of Forest Ecosystem Health Jeff Garnas, is studying the defensive response of ash trees when they are exposed to EAB and methyl jasmonate, a natural plant hormone. When trees detect that herbivores are attacking, they produce methyl jasmonate to defend against the insect. Applying this chemical to trees simulates an attack by an herbivore, allowing a comparison of the reaction between trees that have received natural versus simulated attacks. Johnson says the project’s overall goal is to evaluate how effective top-down forces (i.e., specialized natural enemies, such as introduced biocontrol agents) and bottom-up forces (i.e., plant defenses) are causing mortality to EAB across a range of small diameter green and white ash (3–15 cm DBH) that will remain in forests after EAB has invaded and killed most, if not all, of the larger ash trees. “Understanding how effective top-down and bottom-up forces are in killing EAB in smaller ash is important for managing EAB and tree populations in ‘aftermath forests, ’ where most of the standing ash greater than 5 centimeters DBH have been killed, ” he says.

Johnson also wants to understand a tree’s response time required to defend against EAB and the chemical compounds the trees use to kill the insect. The project is part of a larger study that builds off research that was originally conducted in the Midwest to determine the defensive capacity of ash trees and whether introduced biological control agents can successfully parasitize EAB. understand how resistant, or not, younger or smaller trees are to EAB, as these will be the remaining trees as larger ash die or as the seedling layer of ash begins to mature into a susceptible size to EAB, ” he says. Some early takeaways from the research suggest that the defensive chemistry of green and white ash in the Northeast may differ as compared to previous studies from trees in the Midwest, which makes Johnson’s data unique and important for New England.

Trees also rely on natural enemies to keep invasive insects in check. For EAB, that would be Tetrastichus planipennisi and Spathius galinae, two species of tiny parasitic wasps that co-evolved with EAB in their native range within Asia. These species have been widely used nationwide to reduce EAB populations. Johnson released the wasps as a biological control agent at the field sites in order to research the impacts they have on the experimental borer’s larvae and trees and to see if the wasps will attack natural populations of EAB also present at the sites. Through his research, Johnson also wants to understand if and how tree resistance and biological control are compatible. Will the heavily defended trees also kill the wasps?

The field work was completed in fall 2021, leaving Johnson with plenty of data to analyze. He plans to publish two reports, which will cover the first two years of research, and a third report, which will cover the changes that were made in the 2021 field season. “Through all of this work, the hope is that we can ‘prime’ the defensive capacity of ash trees, through application of chemicals or by breeding trees that respond more rapidly against herbivores in the future, ” Johnson says. It’s a tall task, but Johnson is encouraged by the support his research has received and the interest people have taken in doing their part to stop the spread of the insect.

DID YOU KNOW?

Trees have natural chemical defenses against pests that harm them. Among those chemicals is a familiar one, hydrogen peroxide, one of many chemicals associated with the hypersensitive response, which is the first defense a tree employs when an herbivore is detected in living tissue. The tree will surround the insect larvae with hydrogen peroxide and other chemicals to either kill the invader or starve it. If successful, trees will often cover the damaged region with callose tissue, which explains why trees have so many scars under their bark.

Stacie Hernandez is an easement steward at the Forest Society.

Read more about Johnson’s research project on the following page.

Step by Step

Story and Photos by Stacie Hernandez

Over the course of Todd Johnson’s three-year study, different methods were used to collect data necessary for his research. In the first two years of his study, Johnson researched the defensive chemistry of ash trees in four size classes. By studying trees treated with emerald ash borer eggs, methyl jasmonate, or no treatment at all, Johnson tracked how tree defensive chemistry changes across these three conditions, the mortality of EAB across the different size classes, as well as the effectiveness of the introduced parasitic wasps. In the third year, Johnson focused on two size classes and studied how changing the timing of methyl jasmonate application could increase or decrease mortality to EAB. In all three years, the trees were introduced to parasitic wasps that are known to target EAB, and the trees were removed for study afterward.

Each year prior to the initiation of the study in early June, Johnson and Casey Coupe, a lab technician at UNH, searched for ash trees that had not already been impacted by EAB in the greater Durham area. Across three years, approximately 80 locations were scouted for the presence of green and white ash trees. When appropriate sites were found, trees were randomly selected in one of four size classes. Some of the trees that were used were located on Forest Society land, including Jennings Forest in New Durham in 2020, and Powder Major Forest in Madbury in 2021, as well as other state- or town-owned forests. The steps Johnson followed in his research are outlined below.

2

1) A baseline sample of the tree’s phloem tissue is collected to detect any chemicals present in the tree prior to treatment.

2) The first treatment is the placement of EAB eggs on the bark. The eggs, which are the size of the tip of a pencil, are placed in the beginning of June when they would naturally be laid. The process includes scraping the top layer of bark, sticking eggs in the bark, and protecting the treated area from the elements with Tyvek wrap.

3) When the eggs hatch after a couple of weeks, Johnson and Coupe apply a naturally occurring plant hormone, methyl jasmonate, as the second treatment to some of the trees. Methyl jasmonate is a hormone trees produce upon the detection of herbivores. For the first two years of the study, methyl jasmonate was applied to trees without EAB, to understand how the plant hormone alone changes plant defensive chemistry. In the third year of the study, methyl jasmonate was applied at different points in time to trees with and without EAB. This was done to see if trees could be given an early warning prior to attack and to determine if early application of methyl jasmonate would affect the survival of EAB.

4) After treatments are finished, a second phloem sample is collected to detect the chemical compounds the plant activated as a defensive reaction.

5) Parasitic wasps (T. planipennisi and S. galinae) are then released to measure biocontrol success in EAB larvae.

6) After a couple of months, the tree is cut into three log sections: two from the top (under the crown) and one from the lower artificially infested section. Beetles in the Agrilus genus typically attack from the crown downwards because it is warmer and they are attracted by the ash leaves. It is important to collect the top sections to observe if the tree was naturally infested with the borer.

7) The bark of the tree is peeled back very carefully to observe the gallery—the larval tunnel of the borer—and to collect the larvae that hatched from the eggs. This is done to determine the survival and developmental rate of the EAB larvae to observe the impact after treatment and the rates of parasitism of the wasps across different size classes and tree species.

8) After collecting the larvae from the bark, Coupe analyzes the specimens. He confirms the developmental stage of each EAB larva and dissects them under the microscope to look for internal parasite eggs to determine how successful the parasite releases were at the site.

9) The data is reviewed and presented at meetings and conferences, including the Northeastern Forest Pest Council and Entomological Society of America. The work will also be submitted to science journals for peer review. If accepted, the research will be published for other scientists and practitioners to learn from.

6

Left: An emerald ash borer larva is pictured on top of an ash log after being carefully extracted from a gallery. Right: Ash trees stripped of bark and emerald ash borer larvae are scattered on the ground in Johnson’s research site.