PARENT SESSION
OOS 2: Anthropogenic Disturbances to Western Alpine Lakes: Past, Present, and Future .
Organized by: JE Saros and CE Williamson
Monday, August 2, 8:00 AM to 11:30 AM, Meeting Room E 143.
Mountain lakes as indicators of human and natural stressors: Past patterns, modern concerns and future forecasts.
Leavitt, Peter*,1, Vinebrooke, Rolf2, Schindler, Daniel3, Hampton, Stephanie3, Fradkin, Steven4, 1 University of Regina, Regina, SK, Canada2 University of Alberta, Edmonton, AB, Canada3 University of Washington, Seattle, WA4 Olympic National Park, Port Hope, WA
ABSTRACT- High elevation lakes are thought to be sensitive to both natural (climate, UV radiation, biotic impoverishment) and anthropogenic disturbance (invasive species, land use, atmospheric pollution), yet little is known of patterns or controls of long-term ecosystem variability, nor of the relative importance of human and natural forcing factors. Here we summarize new insights from high-resolution paleoecology (algae, pigments, stable isotopes, geochemistry), lake surveys and ecosystem experiments and propose a conceptual model for regulation of the primary production and structure of mountain lakes. Comparison of low- and high-elevation sites reveals that, in the past, montane lakes have been sensitive mainly to changes in allochthonous subsidies of dissolved substances (C, nutrients). Therefore, as continued global warming is expected to increase these fluxes, alpine lakes may become less sensitive to human activities in the future.
Key words: limnology, climate, alpine, paleoecology