Part 4: Memories of Migration
By Catherine Schmitt, Science Communication Specialist at Schoodic Institute
On a warm, buggy morning in mid-June, Penobscot Nation forester Ben Stevens went into the woods in tribal territory near Brownville Junction to see how the trees were doing. A rough road had been cleared to a stand of mixed hardwoods. A few large white ash, sugar maple, and disease-tolerant “clean” beech cast dappled shade over the half-acre area where diseased beech had been cut, the brush piled around the edges to deter deer. Scattered throughout were young whips of white oak and shagbark hickory, among the thousands of bare-root saplings planted this spring by Stevens with the help of Wabanaki Youth in Science crews. Stevens was pleased to see white oaks leafing out, although most of the shagbark hickories were still dormant.
The project, funded by the Bureau of Indian Affairs with additional support from the U.S. Department of Agriculture Natural Resource Conservation Service, continues a long, long history of Wabanaki forestry and what today might be called “assisted migration.”
People have been moving plants around as long as people have been moving around. Just as they expanded the range of maize and other plants, Indigenous people of North America promoted the migration of fruit and nut trees, such as white oak. The rate at which oak spread north and west from Appalachian Mountain refugia after the glaciers melted was much faster than what could be accomplished through pollen drift or seed dispersal alone. Scientists attempting to model the distribution of oak savannas elsewhere in the Northeast, in Haudenosaunee territory, could only approximate oak distribution if they included humans as a factor.
Similarly, in the upper Midwest, the forests of the Menominee people—the oldest continuously “managed” forests in what is now the continental United States, “have always been novel,” according to Mike Dockry of the University of Minnesota. “Menominee people lived at the edge of the ice. There were people there, moving things, moving seeds. Their name is ‘Ancient Ones/Movers.’ Our people have always moved plants,” he said in a 2023 presentation. Humans have a responsibility to help maintain the ecological function of forests, he said. “These are our relatives.”
Stevens walked around the plot, which looked similar to other plantings by conservation organizations seeking to ensure a forest future. The practice remains experimental—trees grow slowly, after all—and is still somewhat controversial within the conservation community.
Many of those educated only about the damage people have done to forests and cultured in ideals of wilderness and “untouched” nature have resisted the idea of assisted migration. Discomfort and fear were evident at a recent meeting hosted by the White Oak Project in March in Bangor.
White Oak Project lead Kathy Pollard grew up roaming and foraging in the white oak country surrounding her family home in southeastern Massachusetts. She knows white oak as a basket splint material and food for wildlife and people. She has shared lessons learned from her father, of Cherokee and settler descent, with her daughter, Ann Pollard Ranco, a citizen of the Penobscot Nation. With support from Maine Community Foundation, earlier this year they convened a group of land trust and education staff to explore opportunities for cultivating and planting white oak.
“This is essentially a scaling up of what we’ve been working on with schoolchildren and many adults for the past seven years: planting out white oak, American chestnut, black walnut, and butternut to increase the abundance of food in their communities for human and other-than-human neighbors,” Pollard explained. “We want children as well as adults to understand that the narrative does not always have to be that humans only cause ecological harm, or that the adage ‘take nothing, leave no trace’ is the only ethos that humans must abide by in their interactions with nature. By planting food bearing permaculture, they all take part in something that turns these narratives upside down and this enriches their connections to nature. This is really important for children—especially in these times of climate change as we can collectively accomplish something positive, for the benefit of all.”
Attendance at the meeting, held in the one-time Lumber Capital of the World, revealed the desire to engage that comes from our innate connectedness to nature. People were curious about white oak, and the idea of bringing the species into spaces where it doesn’t currently grow.
However, participants also discussed challenges, including questions about what else comes along with the trees (jumping worms, diseases, fungal pathogens) and impacts on ecosystems (wildlife, genetic diversity).
In Acadia National Park, concerns about unintended consequences and the lack of information about ecosystem impacts led the National Park Service to decide against introducing warm-climate shrubs. Instead, the park is working with neighbors to collect data on the same species used in landscaping in yards and gardens.
Because gardeners, of course, assist with migration all the time. At the white oak meeting, one Orono resident talked about her experience growing groundnut and beach plum. She wondered aloud, “Am I disrupting the balance, creating some kind of ‘Plum Nation’?”
Apprehension originates with knowledge that people moving plants (and animals), intentionally or accidentally, has not always gone that well. There is fear of causing further harm. But these same people also know the threats posed by invasive species, and the need for intervention. They worry that if we do nothing, and trees are lost to hemlock woolly adelgid and other threats, preserves will end up covered in invasive vines and shrubs (“all bittersweet”). They no longer take the forest for granted—which is easy to do in the most forested state in the nation.
“It’s important to consider the potential harm, but not let it deter us,” said Pollard. She envisions planting white oaks in “a few pockets here and there,” including on Blue Hill Peninsula, where Pollard said they once thrived in abundance until they were all cut down for ships and barrels during the colonial era. The idea is “to give the trees a little bit of a head start in what will be a slower process of natural migration northward. Planting white oak and other drupe and mast-producing hardwoods can build a sense of hopeful abundance.”
Around the corner from the meeting room at Eastern Maine Community College, two “wild” white oak trees grew in a scrap of forest next to a paved path and the highway. Evidence, perhaps, of a climate getting ever warmer.
Penobscot Nation forester Ben Stevens, who is Passamaquoddy and Maliseet, remembers seeing white oak trees growing in his ancestral home in what is now Tobique, New Brunswick, when he was fourteen years old. He knows the trees grew here once, and could grow here again.
Penobscot Natural Resources Director Loring had already planted some American chestnut trees. But he hesitated when Stevens first presented the idea to him. “I had to think about it. Could we try a small area?”
Stevens formerly worked as an arborist in urban settings, and so he noticed when some of the trees in Penobscot forests had dead branches in their crowns, a sign of “transpiration stress.” Warm temperatures and drought force trees to close their stomata to save water, which also means they stop photosynthesis, which over a long enough period can affect tree health. He knows it is getting warmer. “Are we even in the Holocene anymore?”
When Stevens selected which tree species to plant, he was making a decision about what the future will be. The climate is quickly approaching (has reached?) a state not experienced by modern humans.
As a paleoecologist, University of Maine professor Jacquelyn Gill thinks a lot about the long-ago and far-away. Past ecosystems provide information about the capacity of species to move around, she said in a recent presentation hosted by the Northeast Climate Adaptation Science Center. “They also challenge our idea of what is natural, they challenge our conception of ecological baselines for restoration.”
Research by Gill and others demonstrates that trees don’t migrate at a steady pace, but episodically. Forests don’t migrate as a community, but as individual species. And many of the species being planted now alongside existing trees have been neighbors before.
“One of the things that I find really fascinating is if you look at the extent of the ice sheets at the end of the last deglaciation, all of the modern day species that we have now, most of the trees and their associated understory plants, would have been largely hanging out south of that ice sheet, south of the tundra and the boreal forest,” said Gill. “Species migrated south as they were displaced by the ice sheets, and they ran up against the Gulf of Mexico, they ran up against the Atlantic, there was nowhere for those species to go. The southeastern forests were able to accommodate dozens and dozens and dozens of species. We don’t see extinction happening because of that. Eastern tree species coexisted for thousands of years during sub-optimal conditions and then the northern migrants went right back north again as the ice sheets retreated. That tells me there is a lot of capacity for coexistence in these systems.”
Downhill from the Penobscot Nation plots, a small tributary of the West Branch Pleasant River flowed through a wet forest. It felt about 10 degrees cooler beneath the shade of the hemlocks, their lacy branches creating some of the best habitat around for brook trout and endangered Atlantic salmon. Stevens searched in vain for a massive basswood tree he had seen in the winter, when the swampy landscape looked different covered in ice and snow. He passed by equally massive yellow birches, their roots grasping mossy boulders.
When the oldest trees here took root, average annual temperature was four degrees cooler. Winter started earlier, and ended later. But the trees hold in their DNA memory of even greater change, thousands of years ago, when the seeds of their ancestors arrived in the glacier-scoured landscape now called Maine, and millions of years ago, when the cells of their ancestors evolved in a landscape unrecognizable to humans. Trees draw upon this experience to respond to stress, as they grow and reproduce and their population adapts to local conditions. Such adaptation is happening right now in woods everywhere.
Stevens and Loring discussed the work ahead, and possibly monitoring temperature because of the wide range in microclimates across their lands. “There is a lot more we can do,” said Loring.
This is Part 4 of a series.
Click here to read all 5 installments.
About the Author:
Catherine Schmitt is a science communication specialist with Schoodic Institute at Acadia National Park. She writes about research in Acadia and across the National Park System, and also provides communication training for conservation scientists and educators. She is the author of The President’s Salmon and other nonfiction books, editor of the Maine’s Climate Future series of reports (2009-2020), and contributing writer for Northern Woodlands and The Working Waterfront. Schmitt’s writing has been been published in numerous other magazines, newspapers, and literary journals. She previously directed communications for the Maine Sea Grant College Program at the University of Maine, where she also was an adjunct instructor in the English Department. Her writing is informed by her scientific background, which includes a master’s in ecology and environmental science and experience studying lakes, streams, wetlands, and beaches throughout the Northeast.