Relative Significance of Interception and Wind Redistribution in Subalpine Forest Differential Snow Accumulation

In subalpine forests, the relative significance of interception and wind redistribution causing differential snow accumulation varies with species, evapo-sublimation, topography, wind, forest cover density, opening size, and seasonal snow accumulation. Wind induced differential snow accumulation increases with the intensity of selective or partial cutting. On average, wind redistribution accounts for less than 25 percent of the increased snowpack for lighter cuts to approximately 50 percent for complete removal of forest cover density. During a near-minimum snowpack year with lower wind energy, reduced interception losses accounted for 62 percent of the differential snow accumulation in a 6 tree height strip cut on Fool Creek at the Fraser Experimental Forest. Thirty-eight percent was attributable to wind redistribution. During a near-maximum snowpack year with higher wind energy, wind redistribution accounted for at least 58 percent of the differential snow accumulation and 42 percent from reduced interception. Simulated increased snow accumulation using the algorithms developed for reduced interception loss and wind induced redistribution correlate well with snowpack increases observed for various levels and patterns of basal area removal.