Estimates of critical acid loads and exceedances for forest soils across the conterminous United States.
Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US.
McNulty
Steven G
SG
USDA Forest Service, Southern Global Change Program, 920 Main Campus Drive, Suite 300, Raleigh, NC 27606, USA. steve_mcnulty@ncsu.edu
Cohen
Erika C
EC
Moore Myers
Jennifer A
JA
Sullivan
Timothy J
TJ
Li
Harbin
H
D015258:Acid Rain; D000143:Acids / Q000032:analysis*; D000327:Adsorption; D016208:Databases, Factual; D004463:Ecology / Q000379:methods / Q000706:statistics & numerical data*; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D006801:Humans; D009584:Nitrogen / Q000032:analysis; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis; D013455:Sulfur / Q000032:analysis; D014197:Trees; D014481:United States
D015258:Acid Rain; D000143:Acids; D004785:Environmental Pollutants; D012987:Soil; D012989:Soil Pollutants; D013455:Sulfur; D009584:Nitrogen