The importance of in-lake generation of acid neutralizing capacity (ANC) to the neutralization of acidic deposition has been determined for an acidic Adirondack (NY) lake relative to its surrounding watershed. Microbial processes within the sediments of Dart’s Lake significantly altered the aqueous chemistry of the hypolimnion. Reduction of NO3- and SO42- and the production of NH4+ contributed 45, 14, and 32%, respectively, to the production of hypolimnetic ANC. The reduction of NO3~ was a more significant source of ANC generation than has been reported in other lake districts. On an areal basis, in-lake ANC generation (2990 equiv ha-1 yr-1) was greater than terrestrial ANC production (1204 equiv ha-1 yr-1). However on a watershed basis, in-lake ANC generation was minor (<5%) due to the short hydraulic retention time of Dart’s Lake. Neutralization of acidic precipitation in the Adirondack region predominately occurs in the terrestrial system since the hydraulic retention time of Adirondack lakes is short.
ASJC Scopus subject areas
- Environmental Chemistry