Identifying snow indices for forest planning in southern British Columbia

Snow accumulation and ablation rates vary significantly across the forested landscapes of British Columbia. Changes in snow accumulation and ablation through logging and forest re-growth are assumed to have a direct effect on the quantity and timing of streamflow. To minimise the risk of increased spring peak flows, tree height is used as an operational index to changes in snow accumulation and melt in planning forest development. However, detailed measurements at two research sites in the southern interior have shown that inventory variables such as crown closure account for a larger proportion of the variability among stands, and may be more suitable indices to potential changes in runoff, than tree height. In this study, data from a broad range of sites have been analysed to evaluate which inventory variable provides the best local snow-index. Crown closure explained 68% and 57% of the variability in average standardised peak snow water equivalent and melt rate, respectively.