Whitebark pines (Pinus albicaulis) are picturesque, long-lived, and hardy trees that thrive at sites with harsh climates, where few or no other trees survive. Whitebark pine is the dominant timberline tree in subalpine habitats at Lassen Volcanic National Park. Their large and nutritious seeds are prized by wildlife including Clark's Nutcrackers, black bears, and ground squirrels. Other wildlife use trees for shelter. Whitebark pine canopies support lichens and other plants. These trees also stabilize soil and regulate snowmelt.
Clark's Nutcracker and Whitebark Pine
Gnarled whitebark pine survive on the barren subalpine slopes of Lassen Volcanic with the help of their partner, the Clark's nutcracker. These curious birds flock to the trees' twisted branches for their rich, fatty seeds (that contain more calories per pound than chocolate). Fortunately for the whitebark pine, this is a necessary relationship (obligate mutualism) because its seedlings sprout almost exclusively from seed caches the Clark's nutcracker stores to survive harsh winters at high elevation. This partnership has become increasingly important as whitebark pine numbers decrease under attack of natural diseases such as white pine blister rust.
White Pine Blister Rust
More than 300 acres of whitebark pine are potentially susceptible to infection of an exotic pathogen known as white pine blister rust. Monitoring efforts are helping to evaluate the impact of blister rust on this keystone species in Lassen Volcanic National Park. In the nearby North Cascades and Mt. Rainier National Parks, whitebark pine is rapidly disappearing range-wide, and as of 2015 51% and 64% of the remaining live whitebark pines were infected by blister rust in each location, respectively. This high mortality may seriously reduce biodiversity and disrupt many species interactions.
Whitebark Pine Monitoring
Scientists have been monitoring whitebark pine in the Lassen Volcanic since 2012. Park ecologists are working with researchers from the Klamath Inventory & Monitoring Network to determine the current status of the species and long-term trends. Student scientists from programs such as Mosaics in Science and Geoscientists-in-the-Parks assist in monitoring efforts by mapping the distribution and rate of infection in these ancient, alpine trees.
Last updated: November 4, 2020