Long-term stream chemistry response to harvesting in a northern hardwood forest watershed experiencing environmental change

Abstract

Previous studies of harvest impacts on stream chemistry from deciduous forests with seasonal snow cover have shown variable responses and recovery times. We hypothesized that this variability in response and recovery was due to the interactive effects of forest harvesting with regional and global environmental changes. We investigated harvest impacts on stream solute (K+, Na+, Ca2+, Mg2+, Cl–, SO42–, DOC, Si, NO3–, NH4+, total P) concentrations, pH and conductivity under clearcut, selection, and shelterwood harvesting using a before-after control-impact experimental approach. The experiment was conducted at the Turkey Lakes Watershed, a shade-tolerant sugar maple forest within the Boreal Shield Ecozone, over a 36 year period (15 year pre-harvest and 21 year post-harvest) that has experienced climate change and acidification recovery. Harvest impacts on stream chemistry were greatest in the …