Causes of Acidification of Four Streams on Laurel Hill in Southwestern Pennsylvania

摘要

Possible sources of acidity were investigated for four streams on Laurel Hill (southwestern Pennsylvania) where fishkills have been reported since 1960. A study of the chemistry of atmospheric deposition, soil leachate and stream water and fish populations was conducted on these basins during 1980-81, emphasizing dormant season periods with runoff from snowmelt and rain. Although bedrock geology altered the natural buffering capacity of these streams, only acid precipitation could be linked to sharp drops in pH and increases in total aluminum concentrations observed during stormflows in the poorly-buffered streams. The loss of fish populations in poorly-buffered streams was attributed to acidification of forest soils by precipitation.