Effects of Fire on Alpine Plant Communities in the North Cascades, Washington

Alpine heath and krummholz communities were studied on Sourdough Ridge at 1,900 m, 29 years after fire. Fire effects are observable in structure and compositional details (species presence, frequency, and coverage) of these communities and in acidity and humus forms of the soils. Unburned krummholz stands are dominated by Abies lasiocarpa and Tsuga mertensiana, with Phyllodoce empetriformis and Vaccinium deliciosum as major understory species. Unburned heath communities are dominated by V. deliciosum, P. empetriformis, and Cassiopemertensiana. Of these species, only V. deliciosum persists as a frequent element on burned sites. Fire effects substantial and persistent increases in diversity of both krummholz and heath communities.