Forest‐cover effects on snowpack accumulation and melt, Central Sierra Snow Laboratory

Abstract

Snowpack accumulation and melt at measurement points within snow courses were related to two forest‐cover variables. Water equivalent of the snowpack on April 1 of each year and melt rate after April 1 per unit of degree‐days above 35° F were studied. Cover variables were the amount of shade from trees to the south of a snow measurement point and the amount of shielding from trees to the north of the point. The amount of shade was expressed as the duration of shading between April 1 and June 15, multiplied by the amount of direct solar energy which would have struck the snow surface in the absence of shading. Shielding was expressed by the ratio of average tree height to distance of the trees from the measurement point. Datairom five points in each of five snow courses for three years of record were analyzed by the method of covariance. The analyses showed a high degree of association between the snowpack and forest‐cover variables. The results are interpreted in terms of the timber‐cutting pattern that would result in maximum accumulation of snow, minimum melt rate, and maximum prolonged release of snow water in the spring.