Climate-Induced Shifts in Alpine Diatom Communities: Linking Neoecological and Paleoecological Approaches to Incorporate Responses to Trophic Forcing

Diatoms are a class of microscopic algae that are sensitive to environmental changes. Diatom fossils from lake sediments in the central and northern Rocky Mountains indicate that various Cyclotella species have increased during the 20th century. This increase is often attributed to climate change, but the mechanisms involved have not yet been tested. To decipher the mechanisms by which climate change has altered diatom community structure, paleoecological analyses will be coupled with experimental approaches. Fossil records from lake sediments will be used along with tree rings to provide information on climate trends over the last 2000 years. A series of laboratory and field experiments will be used to assess the mechanisms by which climate-related parameters drive changes in these diatoms. The broader impacts of the proposed work include a greater understanding of the response of alpine lakes to climate change; many of these lakes are located in national parks and forests and have high aesthetic and recreational value. This research will address several research needs identified by Glacier National Park, hence it will potentially provide critical information to park managers. Saros will speak at Glacier National Park\u27s 2009 Science & History Conference, which is attended by the public. The investigators will also develop a Resource Bulletin on the results as part of the park\u27s series on climate change. This research will also provide training for two graduate and nine undergraduate students