DISSERTATION RESEARCH: The influence of plant-plant interactions on pollination and plant reproduction near poleward range margins

Dartmouth College, Hanover NH

Investigators

Abstract

Climate change may alleviate stressful environmental conditions, such as cold temperatures and a shorter growing season, that directly hinder flowering plants in northern regions. In addition, climate change may alter interactions between plants and other organisms. Will competition with neighbors affect whether plants respond to increasing temperatures? Observations and experiments on shrubs and pollinators at different distances from a glacier will answer this question. The scientific workforce will be strengthened through support for the education and training of a doctoral student and participation of undergraduates. Science communication will be enhanced through citizen scientist participation and outreach to middle-school and high-school students. The stress-gradient hypothesis, which posits that plant-plant interactions transition from being competitive to facilitative with increasing stress, will be extended to include pollinator networks. The low-shrub tundra of Kangerlussuaq, Greenland, which is near the poleward range edge of many plants, including our focal species, Vaccinium uliginosum (Ericaceae) encompasses a gradient of 3 degrees C, which mirrors the expected temperature increase in West Greenland over the next 70 years. Using a vegetation removal experiment, how co-occurring plants affect the reproduction of Vaccinium will be determined. Plant traits associated with pollinator attraction and pollinator visitation will be observed, and pollen supplementation treatments will assess pollen limitation. Fruit set and seed production will be measured to assess pollinator-mediated mechanisms in the stress gradient hypothesis. The outcome will improve understanding of the processes of increasing shrub cover in Arctic tundra.