Influence of variable streamside management zone configurations on water quality after forest harvest

Streamside management zones (SMZs) are a common best management practice (BMP) used to reduce water quality impacts from logging. The objective of this research was to evaluate the impact of varying SMZ configurations on water quality. Treatments (T1, T2, and T3) that varied in SMZ width, canopy retention within the SMZ, and BMP utilization were applied at the watershed scale to two watersheds each. Watersheds with wider SMZs (T3: 110 ft, 100% canopy retention) and improved crossings were not significantly different from unharvested control (C) watersheds for all parameters except nitrate and diurnal stream temperatures. Changes in total suspended solids, turbidity, nitrate, dissolved oxygen, and maximum stream temperature were detected for watersheds treated with the current recommended minimum SMZ configurations (T1: 55 ft, 50% canopy retention) and watersheds with unharvested SMZs (T2: 55 ft, 100% canopy retention) and improved crossings.