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Empirical critical loads of atmospheric nitrogen deposition for nutrient enrichment and acidification of sensitive US lakes

January 1, 2011

The ecological effects of elevated atmospheric nitrogen (N) deposition on high-elevation lakes of the western and northeastern United States include nutrient enrichment and acidification. The nutrient enrichment critical load for western lakes ranged from 1.0 to 3.0 kilograms (kg) of N per hectare (ha) per year, reflecting the nearly nonexistent watershed vegetation in complex, snowmelt-dominated terrain. The nutrient enrichment critical load for northeastern lakes ranged from 3.5 to 6.0 kg N per ha per year. The N acidification critical loads associated with episodic N pulses in waters with low values of acid neutralizing capacity were 4.0 kg N per ha per year (western) and 8.0 kg N per ha per year (northeastern). The empirical critical loads for N-caused acidification were difficult to determine because of a lack of observations in the West, and high sulfur deposition in the East. For both nutrient enrichment and acidification, the N critical load was a function of how atmospheric N deposition was determined.

Publication Year 2011
Title Empirical critical loads of atmospheric nitrogen deposition for nutrient enrichment and acidification of sensitive US lakes
DOI 10.1525/bio.2011.61.8.6
Authors Jill Baron, C. T. Driscoll, J.L. Stoddard, E.E. Richer
Publication Type Article
Publication Subtype Journal Article
Series Title BioScience
Index ID 70036761
Record Source USGS Publications Warehouse
USGS Organization Fort Collins Science Center