INSIGHTS INTO THE EFFECTS OF CLIMATE CHANGE AND ATMOSPHERIC DEPOSITION ON LAKES IN THE UINTA MOUNTAINS, UT USING A VARIETY OF PALEOLIMNOLOGICAL TECHNIQUES

The Uinta Mountains in Utah offer an opportunity to study the effects of climate change and anthropogenic activities (e.g., agriculture, fossil fuel burning) on alpine lake ecosystems because they are located at the juxtaposition of two major climate regimes and are characterized by steep climate gradients. There are hundreds of lakes, many of which are relatively remote, making detection of the effects of climate change and atmospheric deposition easier. Here we review our research findings, which combine a variety of paleolimnological techniques, to highlight the contribution to our understanding of climate change and human activities on remote ecosystems. Our research shows that 1) nutrient limitation in these lakes varies spatially and temporally, such that small changes in either N or P deposition could cause significant changes in alpine lake ecosystems, including increases in lake production, changes in species community composition and decreased diversity; 2) dramatic changes in lake production and diatom community composition  begin in the middle of the 20^th century; 3) despite local human disturbances, such as grazing and fish stocking, almost all recorded changes are the result of nutrient delivery to alpine lakes atmospherically; 4) lake response to increased nutrient inputs varies and is dependent on the lake’s history and its catchment characteristics, and 5) climate change, particularly warming and increased precipitation, could alter the trajectory of lake ecosystem change that has been observed to date. Our research highlights the usefulness of alpine lake records for providing information about the effects of climate change and atmospheric nutrient deposition.