Snow accumulation and ablation in a beetle-killed pine stand in Northern Interior British Columbia

Abstract

This preliminary study examined the impact of mountain pine beetle (Dendroctonus ponderosae) infestation and subsequent canopy mortality on ground snow accumulation and ablation in lodgepole pine (Pinus contorta) stands. During the winter of 2005–2006, meteorological and snow conditions were measured in three stands—dead, alive, and cleared—in Northern Interior British Columbia. Variations in measured snow conditions and meteorological data between stands were assessed. Data were used in an energy-balance model to calculate snow ablation in each stand and estimate effects on meltwater production. Results showed that the dead stand no longer behaved like an alive stand, but had not yet approached cleared stand conditions. Ablation rates in the dead stand remained similar to those in the alive stand, although accumulation was closer to that in the cleared stand. The combination of a low ablation rate and increased ground snow accumulation in the dead stand resulted in a lengthened period of snowpack disappearance. In the cleared stand, however, high ablation rates were sufficient to remove the thicker snowpack earlier than in the dead stand. A multi-year study is under way at a new research site to further quantify the relationship between beetle-kill and its effect on snowpack.