Terrain and Cover Effects on Snowmelt in a Western White Pine Forest

Whether increases in snowpack water that result from cutting timber in western white pine ( Pinus monticola Dougl.) forests of the northern Rocky Mountains can create flood-producing conditions depends, in part, upon the melting behavior of the snowpack under various terrain and forest conditions. Reported are results of a 4-year study which show that snowmelt (ablation) rates are influenced significantly by differences in terrain and forest cover conditions. Differences in elevation, aspect, slope steepness, and forest cover accounted for 74 percent of the variance in snowmelt rate. Forest managers can exert some control over snowmelt rates by choosing the terrain and forest cover conditions suitable for specific forest management practices. Clearcutting of the most dense forest stands on southerly aspects at low to intermediate elevations provides largest increases in snowmelt rates. Partial cutting of timber on northerly aspects at intermediate to high elevations affords the best opportunity to effect reductions in snowmelt rates. Forest Sci. 17:125-134.