Conservation biologist Pete McKinley of the Wilderness Society believes the best hope for maintaining the biological diversity of the eastern United States requires enhanced protection of the Appalachian Trail and its greater landscape. Pete maintains the A.T. landscape is playing — and will increasingly play — a prominent role in the protection and adaptation of the eastern forest and its plants, animals, waters, and soils in the face of habitat loss, fragmentation and, now, a rapidly changing climate.

“The Appalachian Trail landscape is a treasure trove of biological diversity,” he says. “The landscape will thrive and flourish best through conservation that maintains and enhances large-scale ecological connectivity among large contiguous forest blocks.” The ingredients for an un-fragmented forest network that is resilient to climate change are in place along the Trail landscape, but much work remains. Large, biologically diverse and contiguous forest blocks exist along the extent of the entire A.T. — sometimes connected by protected landscapes in meaningful units, sometimes protected merely as a thread and sometimes not protected at all.

By Anne Baker and Dennis Shaffer

The Appalachian Trail Conservancy (ATC), in partnership with the National Park Service, continues to build a coalition of conservation partners under the umbrella of the A.T. Landscape Partnership. The coalition — made up of public and private groups — seeks to connect and conserve the values of the exceptional landscape associated with the Appalachian Outdoors, emphasizing the natural, ecological, cultural, historic, scenic, recreational, and community-oriented qualities that make the A.T. and its surrounding lands so unique. In particular, partners such as Pete and the Wilderness Society believe the A.T. and its ribbon of protected lands provide a significant backbone for maintaining this region’s wealth of ecological values and helping ensure its resilience in the face of climate change and other threats.

Full Circle
Pete, who has worked as a conservation biologist for 30 years, has personal ties to the A.T. landscape that have fed into his longstanding career. In the summer of 1977, in between sailing and fishing trips on the south shore of Cape Cod, Pete read the story of Steve Sherman’s and Julia Older’s walk of the A.T. in the book Appalachian Odyssey. He was still a few years away from his college search, but when the time came, Pete chose Colby College in Waterville, Maine for its biology department and, perhaps more importantly, the college’s active outing club and relationship to the A.T. in Maine.

A week-long hike during freshmen orientation took Pete and a group of his new classmates along the first 17 miles of the Hundred Mile Wilderness, between Bodfish Intervale and Katahdin Iron Works State Historic Site. He chose this trip over other outdoor excursions because of the opportunity to hike and help maintain the section of Trail that was assigned to Colby College by the Maine Appalachian Trail Club. “I even brought my own Hudson’s Bay Cruising Axe lashed to my Kelty Tioga Three external frame pack,” Pete says.

Yet it wasn’t all hiking and Trail maintenance as a Colby student. As planned, Pete received a good education in ecology and went on to graduate school and to a career integrating bird ecology and conservation across the forests of New Hampshire and Maine, and in New Brunswick, Canada. He studied the habitat needs of bird species like the black-throated blue Warbler and the black-throated green Warbler. The field guide range maps for these two species always fascinated him: their breeding range in the northern states spread like a frying pan over northern latitudes, while it turned into the narrow handle along the extent of the southern Appalachians. His first trip to Great Smoky Mountains National Park on the North Carolina/Tennessee border convinced Pete that the habitat for birds such as the black-throated blue warbler was indeed there when he spotted one in a rhododendron growing among trees familiar in Maine such as the yellow birch, spruce, fir, beech, and sugar maple.

“I never felt as though Cape Cod was another place, but rather part of this eastern landscape that included these wilder mountains, different animals and plants, different views, a different culture, even — but to me, it was still somehow part of what I later learned to call the ‘Realm,’ after the words of Benton MacKaye,” Pete says.

MacKaye, the conceptual founder of the A.T., had a vision for the Trail that was much more than a footpath. He envisioned a landscape, or a “realm” as Pete points out, that connected the eastern population centers to the rural and remoteness of the Appalachian Mountains. The A.T. Landscape Partnership returns to this vision as the foundation for its work, desiring to protect a wealth of values characteristic of rural, eastern U.S. Yes, the A.T. is America’s premier long-distance hiking trail, but it is also much more, and it does not exist in isolation. To the millions who visit or live near the A.T., the Trail and its landscape embody a unique and special place.

Inextricably Linked
Pete and his peers at the Wilderness Society have been conducting research that demonstrates the A.T. landscape is worthy of and requires a grand-scale conservation effort. Ecologists at the Wilderness Society recently completed an analysis of Trail conservation values and vulnerability. They measured biodiversity, ecological integrity, and protection status for every one-mile segment of the A.T. to identify priorities for protection or improved management. In partnership with both public and private conservation organizations, the Wilderness Society is promoting and supporting land protection and open-space planning efforts to build upon and connect the diversity of ecological values identified through their work.

Along the entire length of the A.T., habitats transition along a gradient between southern and northern latitudes. Within this large-scaled ecological gradient are smaller ecological gradients as the route of the Trail transitions from valley floors to mountain summits and back down again. The result is a Trail and a landscape that embodies incredible ecological diversity that is derived from the physical and biological conditions of the mountain topography running from Georgia to Maine. The southern Blue Ridge is among the most biologically diverse regions in the United States, possessing many species that occur nowhere else on the continent. This is particularly apparent along the elevational mountain gradients throughout the southern and central Blue Ridge Mountains.

“A day’s hike along almost any

section of Trail traverses an

incredible diversity of life, just

as the Trail itself traverses

much of the biodiversity of

eastern North America.”

The Hundred Mile Wilderness of Maine that is bracketed on one end by Katahdin — the Trail’s northern terminus — includes the wildest lands with the lowest human impact east of the Rocky Mountains. This wildness and lack of impact is reflected in the region’s high “ecological integrity,” a measure of human modification used alongside other measures such as species diversity to identify lands with high conservation value. Ecological integrity is meant to gauge the “wholeness” of ecosystems and inform their resilience in the face of stressors such as habitat fragmentation and climate change. While the natural species diversity at the more northerly latitudes might not be as high as the diversity in the mid-Atlantic states or the southern Blue Ridge, the A.T. passes through a wide range of ecosystem types in every state. “A day’s hike along almost any section of Trail traverses an incredible diversity of life, just as the Trail itself traverses much of the biodiversity of eastern North America,” Pete says. Similarly, while there are regions of the A.T. that possess large contiguous forest blocks of high ecological integrity in northern New England and the southern Blue Ridge, every section of Trail has areas of locally or regionally high ecological integrity vital to eastern forest conservation and resilience.

Stress versus Adaptation
The wilderness quality of the A.T. and its greater landscape are under increasing stress, including habitat loss and fragmentation, air and water pollution, regional development and

Permanent protection of the Trail’s

landscape well outside the National

Park Service corridor will be vital to

the continued survival and resilience

of eastern forest ecosystems.

land use, soil compaction, trampling, invasive species, and illegal collection of rare plants. Compounding the impacts of these threats is a changing climate. The Appalachian region is projected to experience increased temperature and moisture deficit, resulting in geographic shifts in species distributions as they track climate change. Research suggests the Appalachian mountain range may facilitate adaptive movements of animal species in response to climate change, and it has also been specifically suggested that the protected A.T. corridor may serve an important function in adaptation. But the protected A.T. corridor and many of the state, federal, and privately conserved easement lands are insufficient to protect the biological diversity of the great eastern forests dependent on the A.T. landscape. To put it simply, in the face of climate change, permanent protection of the Trail’s landscape well outside the National Park Service corridor will be vital to the continued survival and resilience of eastern forest ecosystems — including their biological diversity, ecosystem, and the recreational and psychological values that are so important to society.

Higher elevation streams throughout the southern Blue Ridge Mountains and High Peaks of western Maine will likely serve as a refuge for species such as the brook trout and Atlantic salmon. High elevation forests throughout the Appalachians have provided refuge for cool temperate species such as spruce, fir, yellow birch, American beech, and sugar maple; songbirds such as the blackpoll warbler, black-throated blue and green warbler and golden-winged warbler; and at northern latitudes, the American marten and moose. Mechanisms of adaptation and resilience include population movements upslope and within complex mountain topography and northerly shifts of animal and plant species along the Appalachians to higher latitudes. These mechanisms often require the contiguous blocks of intact and connected forest found throughout the Appalachian landscape. These intact forests possess the kind of biological diversity that is associated with large-scale connectivity and, while some of those forests are protected from development, others are in danger of mismanagement or even permanent loss through land-use conversion.

The Bigger Picture
The ecological integrity and biological diversity values of the A.T. landscape are the beneficiaries of the work of the Wilderness Society and other conservation organizations and agencies that make up the A.T. Landscape Partnership. There has been a great deal of scientific research and data analysis focused on the great landscape surrounding the A.T. and, to advance that research, the ATC and the National Park Service are in the planning stages for a Science and Stewardship Summit for the A.T. Landscape Partnership. The goal for this gathering is to bring together leaders in the fields of science and ecology to share research and analysis and develop the tools needed to make data and analysis models accessible to those who are leading the on-the-ground conservation work across the A.T. landscape. The summit is planned for the spring of 2019. Although the summit participation will be limited based on funding and space, the outcome of the event will be shared with a broad audience of conservation partners. The resulting data models and scientific expertise will be incorporated into conservation planning work with the goal of educating and engaging those who live, work, and play within the Trail and its landscape. Hopefully, the summit will lend itself to a comprehensive action plan that A.T. communities can take ownership of as stakeholders continue to accelerate the pace of conservation in this cherished landscape.

Despite his vision, Benton MacKaye could not have foreseen the present day need and expectation that the A.T. and its associated landscape would serve in large-scale biological conservation. For its first 70 years, the Appalachian Trail Conservancy was known as the Appalachian Trail Conference, and it was dedicated primarily to mapping, blazing, building, and conserving the narrow footpath itself. Now —through the A.T. Landscape Partnership — the ATC, the National Park Service, and partners like the Wilderness Society are laying the foundation for the conservation of the wilderness and connectedness of the great eastern Appalachian Mountains that MacKaye prized for the Trail’s original purposes.

Thanks to research ecologists Greg Aplet, Travis Belote, and Pete McKinley for contributing to this article.

For more information about the A.T. Landscape Partnership visit: