Natural regeneration of whitebark pine: Factors affecting seedling density

Abstract

Whitebark pine (Pinus albicaulis) is an ecologically important species in high-altitude areas of the western United States and Canada due to the habitat and food source it provides for Clark’s nutcrackers, red squirrels, grizzly bears, and other animals. Whitebark pine stands have recently experienced high mortality due to wildfire, white pine blister rust, and a mountain pine beetle outbreak, leading to questions about the species’ long-term viability. The purpose of our study is characterize the age- and size-class structure of whitebark pine at the landscape level, as well as identify factors that influence whitebark pine seedling density. We considered variables describing stand composition and structure, understory community composition, topographic characteristics, and climatic regime. Logistic regression models identified 10 variables as potentially important predictors of presence/absence of whitebark pine seedlings, including forest type, cover of Vaccinium scoparium, seedling density of other species, forb cover, and summer minimum and maximum temperature. Although whitebark pine regeneration is abundant in many areas, long-term monitoring will be necessary to assess the survival of younger size and age classes, especially as these classes become potentially susceptible to insects and/or white pine blister rust over time.

Citation

Goeking, S.; Izlar, D. 2014. Natural regeneration of whitebark pine: Factors affecting seedling density. The International Forestry Review. 16(5): 133.