SS3.06 Large Scale Change in Prominent Ecosystems
Date: Wednesday, June 12, 2002
Time: 10:30:00 AM
Location: Lecture Theatre
 
CarrickHJ, Pennsylvania State University, University Park, USA, hjc11@psu.edu
 
PATTERNS IN LAND-USE AND LIMNOLOGY FOR A CHAIN OF LAKES: AN ECOSYSTEM NETWORK LINKED TO THE SOUTH FLORIDA LANDSCAPE (USA).
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Inherent hydrologic links within networks of aquatic ecosystems can produce biogeochemical variation that reflects the cumulative impact some disturbances may impart across entire landscapes. The nutrient content for a chain of lakes (n=20) within the Kissimmee Upper Basin watershed in central Florida (ca 4,000 km2), shows a distinct trophic gradient among lakes (TP range 10 to 150 ug/L). Sediment cores from two lakes at the extremes of this gradient indicate that P-accumulation in both lakes has increased through time. Moreover, lake TP concentration corresponded strongly with the land-use around each lake (r2=0.77, p<0.0001, n=20), and model predictions indicate that lake TP (on average) will increase almost two-fold by 2010. Biogeochemical changes in the Kissimmee chain of lakes will likely have downstream impacts, because the chain feeds several ecosystems in the south Florida landscape (e.g., Everglades).