Print PageWhitebark pine (Pinus albicaulis Engelm.) is an important tree species of high-elevation ecosystems in western North America. Warming climates, an introduced fungal pathogen (white pine blister rust (Cronartium ribicola J. C. Fisch), epidemic populations of native mountain pine beetles (Dendroctonus ponderosae Hopkins), and altered fire regimes are contributing to the decline of many populations. In July, 2011 the U.S. Fish and Wildlife Service added the species to the Federal Candidate list. Whitebark pine is patchily distributed across approximately 5,100 ha on east side of the Cascades in North Cascades and Mountain Rainier National Parks. In 2004, a long-term monitoring program was established to track status and trends of whitebark pine in the two national parks to inform park protection and restoration of these populations. We established and monitored permanent plots, in thirteen whitebark pine stands, across the two parks in 2004 and monitored the plots in 2009. Trends in rates of infection and mortality were calculated for trees, saplings, and seedlings. Evidence of mountain pine beetles were also collected and summarized by park and stand.
Results/Conclusions
Five year trends in conditions of whitebark pines stands were disappointing. In Mount Rainier National Park, the proportion of uninfected trees (>2.54 cm diameter at breast height, dbh) decreased from 37% to 22% while infection rates rose from 15% to 26% and mortality increased from 48% to 52%. In North Cascades National Park, the proportion of uninfected trees decreased from 54% to 32% and infection rates increased from 29% to 39% and mortality increased from 17% to 29%. Infection rates in saplings (individuals taller than 50 cm but <2.54 cm dbh) increased in both parks (25% to 43% in Mount Rainier and 17% to 21% in North Cascades ), although live sapling density remained stable. Incidence of mountain pine beetle was fairly low in each park (3% of sites in North Cascades and <1% of sites in Mount Rainier).
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