Long-term measurements of microbial biomass and activity at the Hubbard Brook Experimental Forest 1994 – ongoing

Long-term monitoring of soil nitrate (NO3-) and ammonium (NH4+) concentrations, microbial biomass carbon (C) and nitrogen (N) content, microbial respiration, potential nitrification and N mineralization rates, pH, and denitrification potential has been ongoing at the Hubbard Brook Experimental Forest since 1994. Samples have been collected in the Bear Brook Watershed (west of Watershed 6) beginning in 1994. In 1998, our sampling regime was extended to Watershed 1 in an effort to monitor and quantify microbial response to a whole-watershed calcium addition. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.