Stewardship and Science Intersect at Alder Stream Wilderness Preserve

Studying Tree Fecundity in the Face of Climate Change

Becky Clough, NEWT’s Northern New England Land Steward, set out for Alder Stream Wilderness Preserve in central Maine on a balmy day this past July. That afternoon she was to meet with Professor Jim Clark, the Nicholas Distinguished Professor of Environmental Science at Duke University. The Preserve is host to a research site of a global study Clark is conducting titled “Biodiversity Change: Tree Fecundity & the Next Generation of Forests.” The study seeks to document the effects of climate change on the reproductive success of different tree species, and to analyze how changes in that reproductive success shape the wider forest ecosystem.

Clark’s project is an example of the research possibilities offered by NEWT’s Preserves and Conservation Easements. While NEWT conducts its own ecological research via its Wildlands Ecology program, outside scientists and scholars may apply for research permissions on NEWT lands by reaching out to Shelby Perry, director of Wildlands Ecology.

Alder Stream is particularly enticing for tree researchers, or “dendrologists,” because the Preserve hosts what may be the largest grove of reproducing American Chestnuts left in the wild. Virtually all mature American Chestnuts succumbed in the twentieth century to chestnut blight, a non-native fungus that spread throughout North America and killed an estimated three to four billion chestnut trees. Today, one can easily find chestnut saplings sprouting from the stumps of toppled or logged trees in eastern forests, but the vast majority of these saplings are killed by the blight long before they reach the size and age necessary to produce seeds, or “mast.” The Alder Stream chestnuts, then, are something of a treasure for scientists studying this species that once flourished in our woods.

But Clark wasn’t solely interested in the chestnut grove. He was also visiting the Alder Stream research site to check on the seeds of other trees, including oak, beech, and pine. These species all provide important forage, like the chestnut once did, for wildlife as they prepare for the Northeast’s long winter.

Once Clough and Clark had met and were sufficiently coated in bug spray (the black flies may have taken the day off, but the mosquitoes did not), the two hiked to the chestnut grove. There, Clark gave Clough a quick “citizen-science mini training,” as she described it, in his research methodology. The project measures tree reproduction rates, or “fecundity,” in two ways: observations via binocular of the development in the treetops of the coming autumn’s mast, and last year’s mast as evaluated by the debris in 20 to 30 “seed traps” Clark’s lab assistant, Jordan Luongo, had built and placed around the research area.

Clark surveys last year’s mast in one of 20 to 30 “seed traps” he and his lab assistant placed around Alder Stream Wilderness Preserve.

Before long, Clough was estimating mast abundance in the canopy, measuring tree diameters, and entering that and other data into the project’s database on iNaturalist, a citizen-science tool that allows expert and non-expert observers alike to log their observations of the natural world. Then Clough and Clark headed to an area of the chestnut stand that hosts younger trees. There, Clough helped Clark inventory seeds that had collected in the traps. The two bagged chestnut burrs, beechnuts, pinecones, and other seeds, and then labeled each bag with the corresponding number on each trap. Clark would bring these seed bags back to his lab in North Carolina to inventory the contents and add the data to his study.

For Clough, who has spent years learning by heart the intricacies of the forests of northern New England, the data collection was a high point of an enjoyable and stimulating day on the Preserve: “Getting the chance to walk in the woods with a tree expert was a particular highlight. Jim’s kind demeanor also made me feel like there were truly no dumb questions, so I asked anything that came to mind, as my job certainly makes me wonder about a lot as I walk through the Maine woods.”

The motivation behind Clark’s project mirrors that of the research done by NEWT’s Wildlands Ecology program. An understanding of the ecological shifts underway in even a small forest research plot in the Maine woods, or the Adirondacks, or the marshes of southeastern Massachusetts, may provide clues about how ecosystems of the same type across the globe are faring—and adapting—under modern pressures, such as introduced forest pests and rising temperatures.

The importance of this research is symbolized well by Alder Stream’s chestnut grove, a rare remnant of a once-mighty species whose decline changed the ecology of the Northeast’s forests. Other tree species like ash, beech, and hemlock are grappling with similar challenges today. A clearer understanding of these unfolding shifts can inform conservation strategies for the coming decades, and bolster the argument for forever-wild conservation as a potent tool in the fight against biodiversity loss and climate change. As Clough put it, “Clark’s focus on tree fecundity, specifically in the face of a changing climate, brought the Maine woods into a global context.”

Photography by Jerry Monkman Ecophotography.