Anderson, I. C. School of Marine Science, Virginia Institute of Marine Science, iris@vims.edu
Kopácek, J. C. Hydrobiological Institute, Czech Academy of Sciences, jkopacek@hbu.cas.cz
Tobias, C. R. School of Marine Science, Virginia Institute of Marine Science, ctobias@vims.edu
Vrba, J. Hydrobiological Institute, Czech Academy of Sciences, vrba@hbu.cas.cz
Macko, S. A. University of Virginia, sam8f@uva.pcmail.virginia.edu

 
RECOVERY OF ACIDIFIED GLACIAL LAKES AND THEIR WATERSHEDS FROM NITROGEN SATURATION
 
Many central European forested watersheds show signs of nitrogen saturation due to long-term exposure to high levels of nitrogen in atmospheric deposition. Lakes within watersheds of the Shumava Mountains National Park in the Czech Republic show the consequences of nitrogen saturation with low pH, high TN : TP ratios and low trophic status. Although there has been a 30% decline in atmospheric TIN in the last decade, recovery of water quality in Sumava lakes has not occurred at a concomitant pace. In order to determine possible causes for this hysteresis we have attempted to identify sources of TIN to the watershed and measured N-cycling rates in both soils and lakes. Results of analyses of 15N signatures, used to trace sources of atmospheric TIN to watersheds in southern Poland and the Sumava Mountains, suggest that coal burning may be an important source of TIN to Polish watersheds whereas agriculture is a more important source to Sumava watersheds. The rate of lake recovery from excess nitrogen appears to depend on the bedrock, on rates of mineralization and nitrification in watersheds and on development of anoxia and denitrification in the water column.
 
Day: Wednesday, Feb. 3
Time: Poster
Location: Sweeney Center
 
Code: SS50WE1197S