A Sky Island Perspective: New England Alpine Plant Distributions Across the Region

• Main Author: Tirrell, Andrea
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2022
• Subjects: alpine plant community; climate change; island biogeography; mountain top biodiversity; Vermont; Maine; New Hampshire; Botany; Other Ecology and Evolutionary Biology; Terrestrial and Aquatic Ecology; Change Island; Tundra
• Online Access: https://digitalcommons.library.umaine.edu/etd/3734; https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=4784&context=etd

Alpine ecosystems around the globe are at risk due to climate change, human disturbance, and habitat loss. New England alpine zones are small and fragmented, which could make them vulnerable to global change. However, the persistence of tundra relics throughout the Holocene suggests the persistence of these communities in microclimate refugia. Assessing the near-term vulnerability of alpine plant communities is challenged by a lack of standardized, repeat surveys and long-term monitoring data, which presents a challenge for the many agencies monitoring New England’s alpine zones. Island biogeography theory predicts that alpine species richness is a function of area, but this remains untested for the low-elevation alpine zones of the northeastern United States. In this thesis, I first sought to address this knowledge gap with a baseline characterization of alpine plant communities across 8 field sites in Maine, New Hampshire, and Vermont, testing the role of connectivity, alpine area, and topographic complexity on alpine specialist species richness (Chapter 1). I found that connectivity, slope, and elevation, but not area, affected alpine specialist species richness across sites, meaning less isolated sites with high elevations and steep slopes have higher species richness. Secondly, to address the need for new, noninvasive sampling methodology, I field tested low-cost photogrammetry as a tool to create virtual permanent plots, to facilitate long-term monitoring in alpine zones (Chapter 2). In this methods chapter, I demonstrate how 3D image models can serve as an accessible tool for managers of rare and threatened plant communities where permanent structures are not permitted.