BLM Idaho works to conserve Whitebark Pine trees

BLM Idaho specialists use all the tools in their toolboxes to manage, protect, and restore the Whitebark Pine (Pinus albicaulis)—an iconic, high elevation keystone tree species that provides many ecological services in its habitat. BLM Idaho manages a small, but ecologically important portion of Whitebark Pine’s range (less than 1% of the species’ total range) within the Challis, Salmon, Cottonwood and Coeur d’Alene Field Offices.

Since the early 2000s, BLM specialists have worked closely with specialists from the U.S. Forest Service and the Whitebark Pine Ecosystem Foundation to plan and implement Whitebark Pine restoration projects. BLM Whitebark Pine restoration projects are all the more important now, since in December 2020, the U.S. Fish and Wildlife Service published a Proposed Rule to list Whitebark Pine as a Threatened species under the Endangered Species Act, due to population declines from white pine blister rust (an invasive fungal pathogen), mountain pine beetle outbreaks, altered fire regimes, and climate change.

In recent years, all four BLM Idaho Field Offices have surveyed their high elevation forests to evaluate Whitebark Pine stand composition and health. The BLM specialists surveying the forests have discovered that there are more whitebark pine stands than they had thought. One of the first projects the BLM implemented was a study in the Challis Field Office involving verbenone, an anti-aggregating pheromone. This pheromone helps protect whitebark pine trees by inhibiting mountain pine beetles’ ability to mass-attack and overwhelm a specific tree. By stapling verbenone pouches to Whitebark Pine trees, the beetles think that the trees have already been attacked and they should move on to a different tree. The verbenone project was implemented in 2005 and concluded in 2012.

BLM Idaho specialists have also identified whitebark pine “plus trees” in the Challis, Cottonwood, and Salmon Field Offices. “Plus trees” are mature, cone-producing trees that have not been affected by white pine blister rust—even though trees around them have been. “Plus trees” appear to have some genetic resistance to white pine blister rust. BLM Idaho utilizes trained contract crews to climb “plus trees” in the early summer and put mesh cages around cones to prevent Clark’s nutcracker and other animals from eating the cones. At the end of the summer, the tree climbers return to remove the mesh cages and collect the mature cones.

The BLM works with the Forest Service’s Coeur d’Alene nursery to plant the seeds and test the seedlings for genetic resistance to white pine blister rust. Blister rust resistant seedlings are available for planting in areas where there is little natural whitebark pine regeneration, due to fire or excessive mortality from mountain pine beetle or blister rust.

Thinning treatments to reduce competition for whitebark pine have been completed in the Challis Field Office. BLM specialists are planning thinning projects in the Coeur d’Alene, Cottonwood, and Salmon Field Offices. Whitebark Pine is a relatively slow-growing, shade intolerant tree species compared to other high elevation trees, such as lodgepole pine and sub-alpine fir. By removing non-Whitebark Pine tree species, more resources are available for Whitebark Pine trees to grow and thrive.

Whitebark Pine is an amazing tree. Two ecological services provided by Whitebark Pine include that its large root system stabilizes soil and prevents erosion, and its seeds are large, nutritious, and provide food to many bird and mammal species, including grizzly bears. Whitebark Pine trees grow between 6,000-12,000 feet in elevation or above sea level. It is a very long-lived species with some trees documented at over 1,000 years old.

BLM Idaho is excited to have the opportunity to help this species meet the challenges it’s facing.