EVALUATING CATCHMENT AND ATMOSPHERIC DRIVERS OF PHOSPHORUS INCREASES IN MOUNTAIN LAKES OF NORTHEASTERN UTAH
Increasing phosphorus concentrations in many remote, high-elevation waterbodies across the western United States can alter historically low-nutrient aquatic ecosystems. In these remote locations, typical anthropogenic P inputs (e.g. agricultural runoff or waste) are implausible. Here, we investigate alternative mechanisms involving catchment-soil and dust-P inputs to explain increases in P to high-elevation waterbodies. We conducted leaching experiments on soils collected from the Uinta, Wasatch, and Bear River Mountains to quantify the amount of P leached at different pH and temperature treatments. We also collected atmospheric dust from 6 areas spanning northern Utah to determine atmospheric-P deposition rates. We used chemical extraction to determine the proportion of bioavailable-P deposited in dust. Our results reveal minor increases in P leached with increasing soil pH, but potentially significant increases in P with elevated soil temperatures and extended growing seasons projected locally with climate change. These results demonstrate that rising temperatures and prolonged growing seasons due to climate change may alter the nutrient status in remote high-elevation water bodies.
Jessica Scholz (Primary Presenter/Author), Utah State University, firstname.lastname@example.org;