Whitebark Pine in the National Parks of the Pacific States: An Assessment of Population Vulnerability

A comprehensive assessment of whitebark pine (Pinus albicaulis) populations across seven Pacific State national parks reveals significant vulnerability to non-native white pine blister rust and climate-driven mountain pine beetle outbreaks. The study, conducted by the National Park Service, found that blister rust infected 29 to 54% of trees in most parks, except for Sequoia & Kings Canyon and Yosemite, where infections were minimal (0.3% and 0.2%, respectively). Mortality rates due to beetle outbreaks ranged from 10 to 43% in the affected parks, with projections indicating a potential 25% population decline over the next century under worsening conditions. The research utilized a stochastic, size-structured population model based on Crater Lake data to forecast future trends, highlighting the urgent need for monitoring and conservation efforts to mitigate these threats.

Jules, E. S., van Mantgem, P. J., Iberle, B. G., Nesmith, J. C. B., & Rochefort, R. M. (2020). Whitebark Pine in the National Parks of the Pacific States: An Assessment of Population Vulnerability. Northwest Science, 94(2). https://doi.org/10.3955/046.094.0204