MOOSE, Wyo. — Grand Teton National Park (GTNP) is ramping up its activity to protect whitebark pines, a keystone and foundation species in the Greater Yellowstone Area (GYA) facing continued threats.
On Dec. 15, 2022, the U.S. Fish and Wildlife Service (USFWS) listed the whitebark pine as a threatened species under the Endangered Species Act due to blister rust, native mountain pine beetle predation, impacts from altered fire regimes and climate change.
According to Laura Jones, GTNP branch chief for Vegetation Ecology Management, whitebark pines have “an ecological role disproportionately large relative to its abundance.” Whitebark pines are often seen as the initial colonizer in areas with difficult growing conditions, improving those conditions by soil development regulation, carbon storage and capture and retention of snow. They also increase quantity and duration of summer runoff and enable other plant species to colonize.
Jones points out that whitebark pine seeds are also an important food and protein source for birds, squirrels, black and grizzly bears and other mammals.
For over two decades, GTNP has been collaborating with Yellowstone National Park (YNP), the U.S. Forest Service and Bureau of Land Management in the GYA to conserve whitebark pine trees.
“Ongoing actions include extensive protection of rust-resistant and cone-bearing trees through verbenone placement, cone and pollen collection, testing for rust-resistance and establishment of a seed orchard and plantings,” Jones says.
GTNP partners with the Northern Rockies Conservation Cooperative and GTNP Foundation to treat select whitebark pines with verbenone in an attempt to reduce beetle infestation of the trees. Verbenone is a pheromone that informs beetles a tree is already occupied and discourages them from invading it; GTNP places verbenone pouches on trees with demonstrated resistance to blister rust. Jones confirms that monitoring of those trees with pouches show that less than 5 percent have been invaded and killed by beetles, while surrounding trees have been infested.
“However, when beetle pressure becomes very high, the pheromone may not be enough to discourage beetles from selecting that tree,” Jones says. “Unfortunately, the beetle ‘outbreak’ has become persistent and the beetle pressure is high.”
Jones says the Park is working towards placing beetle traps at key locations, stripping bark from dead trees before new adult beetles fly and working with YNP and Glacier National Park to partner with American Forests on direct seeding trials for restoration. The trials are anticipated to begin this fall, and GTNP is planning multiple years of direct seeding and planting of whitebark pines.
“While these actions represent a ‘ramp up’ in activity and shift to restoration from ground-laying work that coincide with the listing decision, the Park has been working toward this end regardless,” Jones says. “Nonetheless, the formal listing may have contributed to the success of recent project proposals to new funds available under the Bipartisan Infrastructure Law and Inflation Reduction Act.”
Burning is not a feasible approach in GTNP, where whitebark pine trees are located in remote, high mountain areas.
