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Links Between Episodic Acidification and Soil Calcium Depletion. Streams as Ecological Indicators of Atmospheric Deposition Effects. Streams provide habitat Streams are more susceptible to acidification than lakes. Stream chemistry reflects terrestrial ecosystem processes. Buck Creek,
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Links Between Episodic Acidification and Soil Calcium Depletion
Streams as Ecological Indicators of Atmospheric Deposition Effects • Streams provide habitat • Streams are more susceptible to acidification than lakes. • Stream chemistry reflects terrestrial ecosystem processes.
Buck Creek, Western Adirondack Region, 1990
Published Episodic Acidification Data for the 1990s’ • Hyer et al., 1995 (1993-94) • Lawrence, 2002 (1998-99) • Mitchell et al., in prep ? (1999?) • Driscoll et al., 2001 (1991-1994)
Effects of Acidic Deposition on Soil • Accumulation of Sulfur and Nitrogen • Depletion of Calcium • Mobilization of inorganic Al
August 24, 1998Precip. in previous 6 weeks = 15.3 cm Precip during storm = 9 cm North Tributary pH 4.26 4.12 BC-AA 0 -15 µeq/L South Tributary pH 5.70 4.64 BC-AA 35 -9 µeq/L
September 16-23, 1999Precip. in previous 6 weeks = 3.7 cm Precip during storm = 13.8 cm North Tributary pH 6.34 4.14 BC-AA 164 -94 µeq/L South Tributary pH 6.10 4.84 BC-AA 136 -2 µeq/L
September 16-23, 1999 North Tributary µeq/L SO42- 100 298 NO3- 9.1 149 soil N = 922 kmol/ha South Tributary µeq/L SO42- 92 120 NO3- 5.4 43 soil N = 494 kmol/ha
Soil Chemistry in Spruce Forests NY, VT, NH, ME
Northeastern U.S. ADK, NE NE Adirondacks
Toxic Threshold Ca2+ – (SO42- + NO3-)
SUMMARY Strong link between soils and high-flow stream chemistry. Acid episodes will continue until a) S and N availability drops, and/or b) soil base status improves.
References Lawrence, G.B., M.B. David, S.W. Bailey, and W.C. Shortle. 1997. Assessment of calcium status in soils of red spruce forests in the northeastern United States. Biogeochemistry 38: 19-39. Lawrence, G.B. 2002. Persistent episodic acidification of streams linked to acid rain effects on soil. Atmospheric Environment 36: 1589-1598. Driscoll, C., G.B. Lawrence, A. Bulger, T. Butler, C.. Cronan, C. Eager, K. Fallon-Lambert, G. Likens, J. Stoddard, and K. Weathers. 2001. Acidic deposition in the northeastern U.S.: Sources and inputs, ecosystem effects and management strategies. Bioscience. 51: 180-198.