Bulk precipitation chemistry at the forest and forest village

Abstract

The objectives of this study were to characterize and compare selected physical and chemical properties of precipitation in a broadleaf mixed forest and a village located in the same forest in order to determine the influence of the village on the atmospheric environmental quality of the forest ecosystem. Bulk precipitation samples were collected weekly from October 2005 to July 2011. Precipitation samples were analyzed for pH, electrical conductivity (EC), turbidity, total suspended particles (TSP), total alkalinity (CaCO3), alkalinity (HCO3-), chloride (Cl-), total hardness (CaCO3), Ca hardness (CaCO3), calcium (Ca2+), magnesium (Mg2+), organic matter, total nitrogen (N), sodium (Na+), potassium (K+), nitrate (NO3)(-), phosphate (PO4)(3-), iron (Fe), aluminum (Al), ammonium (NH4)(+), and sulfate (SO4)(2-). The precipitation samples from forest and forest village were significantly different from each other for EC, total alkalinity (CaCO3), HCO3-, Ca hardness (CaCO3), Ca2+, total N, K+, NO3-, and NH4+. Regardless of the study sites, PO43- and Mg2+ were dominant anion and cation, respectively. The orders of cation and anion concentrations were similar for both study sites and they were in descending order of Mg2+ > Ca2+ > Na+ > K+ > NH4+ > Fe > Al > H+ and PO43- > HCO3- > SO42- > Cl- > NO3-, respectively. Overall average monthly values of precipitation characteristics did not show significant difference between months except for pH, EC, total alkalinity (CaCO3), and HCO3-. Significant correlations were found between SO42- and pH, Ca2+, NH4+ and between NO3- and NH4+ for the precipitation event at the forest site. Both study sites had pH values higher than 5.6 due to the neutralization of SO42- and NO3- by NH4+ and Ca2+. Significant correlation coefficients found between the study sites for the same precipitation parameter indicated that both study sites were under the influence of the same emission sources. (C), 2013 Elsevier B.V. All rights reserved.