Research Brief: Understanding the climates impact on Acadia's subalpine plant communities

Looking down on the featherbed, a small mountain pond on the south ridge of Cadillac Mountain

C. Schmitt/Schoodic Institute

Caitlin McDonough MacKenzie, Colby College

The granite ridges of Acadia host unique, isolated communities of sub-alpine plants, including species at the southern edge of their ranges, such as black crowberry and alpine blueberry. As temperatures continue to warm, these habitats above treeline and the plants and animals they support are at risk of disappearing. Many of the plants are believed to be relicts of the tundra that once covered the mountains at the end of the last Ice Age, but the details of this history, and how subalpine plants respond to climate changes at a local scale, are not well understood.

Caitlin McDonough MacKenzie researches the ecological stability of plant communities, reconstructing vegetation changes through time by studying the layers of plant pollen and fossils in the sediment of high-elevation lakes. Building on previous research at Sargent Mountain Pond, in 2021 McDonough MacKenzie will study the sediment of The Featherbed, a pond on the southern slope of Cadillac Mountain, using pollen and fossil data to capture vegetation responses to rapid warming events in the past. With data from wind speed and direction sensors installed at both ponds, she will be able to map the source populations of past and current pollen that drift into the lake as dust and rain.

McDonough MacKenzie is not just interested in data she can measure, but recognizes that humans also hold knowledge in layers of memory. The Wabanaki people have known the mountains and lakes of Acadia for millennia, and their histories and practices may reflect experience of environmental change as well as valued mountain plants. McDonough MacKenzie’s work incorporates Indigenous perspectives of place, to improve climate change vulnerability assessments and illuminate the full history of subalpine vegetation in Acadia.