HR: 17:00h
AN: H34C-05    [Abstracts]
TI: Hydroclimatic controls on eutrophication of lakes in agricultural catchments
AU: * Collins, D B
EM: dbcollins@wisc.edu
AF: Center for Sustainability and the Global Environment, Nelson Institute for Environmental Studies University of Wisconsin-Madison, 710 University Avenue, Madison, WI 53726, United States
AU: * Collins, D B
EM: dbcollins@wisc.edu
AF: Center for Limnology, University of Wisconsin-Madison, 680 North Park Street, Madison, WI 53706, United States
AU: Carpenter, S R
EM: srcarpen@wisc.edu
AF: Center for Limnology, University of Wisconsin-Madison, 680 North Park Street, Madison, WI 53706, United States
AB: The long-term driver of contemporary cultural eutrophication in lakes is generally the supply of phosphorus (P) from agricultural catchments, via manure or fertilizer runoff. However, short-term recycling of P from lake sediment also plays a critical role in sustaining eutrophic conditions after brief high loading rates subside. A comprehensive understanding of the vulnerability of lakes to eutrophication thus requires the synthesis of hydrological, biogeochemical, and limnological data and models across linked land-lake systems. One question such a synthesis may address is the vulnerability of lakes to eutrophication under different climatic conditions. Drawing from global runoff and local P-dynamics data, we develop a lumped model linking dynamics of water column and sediment P to catchments' biogeochemical and hydrological responses across a gradient of mean annual precipitation. Results suggest that climates with an intermediate range of mean annual precipitation are most vulnerable to cultural eutrophication, but only after sufficient time has passed to allow the accumulation of P in the sediments. Vulnerability declines in dryer climates owing to a lack of runoff and P loading, and in wetter climates to increased flushing of P from the lake. The results provide insights for understanding the potential impacts of regional climate change, as well as the vulnerability of regions that are aiming to increase the use of agricultural fertilizer.
DE: 0438 Diel, seasonal, and annual cycles (4227)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1807 Climate impacts
DE: 1813 Eco-hydrology
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2007 Fall Meeting