Power Plant Influences on Bulk Precipitation, Throughfall, and Stemflow Nutrient Inputs

Abstract

AbstractInputs of SO42−, total N, PO43−, K, Ca, and Mg via bulk precipitation, throughfall, and stemflow have been investigated over a 3‐yr period at two forest study sites on the Cumberland Plateau of Tennessee. The Cross Creek Watershed located 19 km from the Widows Creek coal‐fired power plant was used to represent inputs to a forest site in the immediate vicinity of a large emissions source. The Camp Branch Watershed having similar forest cover and soil types, but located in an area 99 and 76 km from the nearest major point sources, was used to represent inputs as a function of regional conditions. Location exhibited its greatest influence on stemflow inputs, with only PO43− and K failing to exhibit a statistically significant (P = 0.05) increase in stemflow input at Cross Creek relative to Camp Branch. Although throughfall SO42−, K, Ca, and Mg input values were higher at Cross Creek, they were not significantly higher than the Camp Branch values. Nitrogen and phosphate throughfall input values were lower at Cross Creek than Camp Branch, but again lacked statistical significance. Nitrogen and phosphate in bulk precipitation were significantly elevated at Cross Creek while other elements and compounds did not respond to location. Based on this evaluation most atmospheric contributions to bulk precipitation, throughfall, and stemflow elemental inputs appear to be of regional rather than local origin.