The effect of patch clearcutting on the water balance of a subalpine forest slope

Peak water equivalent in the snowpack, soil moisture content before, during, and after snowmelt, and soil moisture content during the growing season were monitored on three adjacent study plots on a 35 percent north-facing slope. After 2 years of calibration, the center plot was clearcut, creating a 4-tree height opening in the 20-m stand. During the next 3 years, up to 50 percent more snow water equivalent accumulated in the opening than in the upwind control. This increase is evident both for individual events and for the entire season. The increases occurred primarily during the snowfall events, where no measurable redistribution occurred between events. Soil water recharge in all plots was not affected by clearcutting. However, significantly less soil water depleted (-5.1 cm) from the clearcut plot than from either the up or downwind forest after harvest. Increased snowpack accumulation in the opening accounted for 14.8 cm of the estimated 19.9 cm increase in water available for streamflow for the clearcut; reduced soil water depletion accounted for the remaining 5.1 cm.