The trees are threatened from several sides, from fire suppression to infestation of insect species, but blister rust may pose the greatest danger of all. Scientists now fear the disease could wipe out more than 90 percent of the whitebark population. Blister rust, which thrives in wet conditions, may also be adapting to drier climates. The result is an increase in whitebark pine infection and mortality in the Greater Yellowstone Ecosystem. The ecological significance of whitebark pines has only recently been recognized.
Conservationists point to a vital correlation between the trees and grizzlies.
Bearing large seeds that are high in fat, whitebark pine trees provide an important food source for many animal species. Whitebark pine seeds are a major component of the grizzly bear's diet. Biologists say the nutritious seeds are one of the four major food sources that grizzlies depend on. Rich in digestible lipids, whitebark pine seeds can provide as much as 40 percent of a bear's winter fat layer. Research also suggests that the seeds contain estrogenic compounds, which may increase grizzly reproduction.