NSF Award
2326020
The mountaintops of the northeastern United States support unique ecosystems of Arctic and alpine plants, which exist as small, isolated patches above the treeline. It is thought that these plant communities have existed since the retreat of the glaciers approximately 13,000 years ago, surviving through the natural climate changes of the past as well as human-caused warming over the last century. These vulnerable ecosystems are culturally important, drawing thousands of hikers to these peaks every year. They also pose a challenge for the management agencies tasked with protecting them from climate change, trampling, overuse, and other threats. At the same time, they may hold clues about how small, isolated populations can survive periods of climate change. Does the answer lie in the plants themselves, in their ability to adapt quickly to changing environments? Or is the secret to their success in the sheltered nooks and crannies of bedrock, which provide a cool refuge during the heat? And to what extent are plants disappearing, and perhaps reappearing, on these mountaintop “islands” over time? To answer these questions, a team of researchers from the University of Vermont and the University of Maine will sample alpine lakes in the Adirondacks, the Green Mountains of Vermont, the White Mountains of New Hampshire, and Katahdin in Maine, analyzing the DNA of ancient plants to understand whether species have truly persisted in the thousands of years since the end of the last ice age. At the same time, they’ll be investigating the modern-day plants of the northeast alpine region, both in the field and in experimental gardens. Finally, researchers will share their results in a podcast showcasing alpine plants and the people who work with them, as well as in a new AI-powered app (presented during training workshops at the Northeast Alpine Stewardship Gatherings) that will help managers and others make informed decisions about how best to steward this vital natural heritage through the coming century. The overall goal of this work is to help scientists, volunteers, and managers understand how better to support not only alpine plants across the northeast, but in other parts of the world where rare or isolated species are faced with climate change and other threats.<br/><br/>This project will integrate tools from paleoecology, community ecology, trait ecology, population genomics, and geography to develop an understanding of how alpine plant communities in the northeast assembled and persisted. Focusing on the Adirondacks (NY), the Green (VT) and White (NH) Mountains, and Katahdin (ME), the research team will first characterize the last ~13,000 years of vegetation dynamics at the species level using ancient DNA from alpine sediment cores. To characterize changes in response to historic warming, they will then conduct plant surveys to estimate species turnover over the last century by comparing modern-day flora with historic survey records. The team will then combine data from common garden experiments, microclimate sensor arrays, functional trait analyses, and coalescent modeling from population genomic data to reveal past and contemporary demographic dynamics and clarify the relative roles of microrefugia, phenotypic plasticity, and local adaptation in driving biodiversity turnover across millennial, centennial, and decadal timescales. The study will focus on six focal taxa that represent key alpine plant functional types (graminoids, forbs, and dwarf shrubs). The resulting multi-dimensional biodiversity data will inform predictive models that will be shared with regional managers after being tested against past known biodiversity dynamics. Through this novel, integrative approach, the project aims to increase predictive power in forecasting biodiversity dynamics in fragmented populations in a warming world by quantifying the relative roles of climate refugia, metapopulation processes, phenotypic plasticity, and adaptive capacity in an integrative framework.<br/><br/><br/>This proposal is jointly funded by the Biodiversity on a Changing Planet program and the Established Program to Stimulate Competitive Research (EPSCoR).<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
