The U.S. Fish and Wildlife Service said this week it has determined the whitebark pine warrants protection under the Endangered Species Act, but that adding the species to the federal List of Endangered and Threatened Wildlife and Plants is precluded by the need to address other listing actions of a higher priority.
Roughly 44 percent of the species' range occurs in the United States in Wyoming, Montana, Idaho, Nevada, California, Oregon, and Washington. The remaining 56 percent of the species range occurs in British Columbia and Alberta, Canada.
Whitebark pine typically occurs on cold and windy high-elevation or high-latitude sites in western North America. It is considered a keystone species because it increases biodiversity and contributes to critical ecosystem functions.
The Service will add the whitebark pine to the list of candidate species eligible for ESA protection and review its status annually.
When a warranted but precluded finding is made for a species, the Service classifies it as a candidate for listing.
The Service determined that threats to the whitebark pine include habitat loss and mortality from white pine blister rust, mountain pine beetle, catastrophic fire and fire suppression, environmental effects resulting from climate change, and the inadequacy of existing regulatory mechanisms.
Whitebark pine is experiencing an overall long-term pattern of decline, even in areas originally thought to be mostly immune from the above threats. Recent predictions indicate a continuing downward trend within the majority of its range.
While individual trees may persist, given current trends the Service anticipates whitebark pine forests will likely become extirpated and their ecosystem functions will be lost in the foreseeable future.
On a landscape scale, the species appears to be in danger of extinction, potentially within as few as two to three generations. The generation time of whitebark pine is approximately 60 years.
Service officials said they were aware this finding may raise some concern about the status of grizzly bears, which are known to use whitebark pine as a food source.
The Service says it has 25 years of data that indicate grizzly bears are not dependent on whitebark pine seeds for their survival. Because whitebark seeds are not a naturally reliable food source, grizzlies have been coping for millennia by switching to other foods when whitebark pine seeds are unavailable by consuming other readily available foods such as ungulates, ground squirrels, i9nsects, roots, mushrooms, and other vegetative matter. Therefore, the Service says it does not believe this finding will impact grizzly bear recovery.
Currently, there is no known way to stop whitebark pine mortality caused by white pine blister rust and mountain pine beetle.
The majority of whitebark pine occurs on Forest Service managed lands, and the Forest Service has implemented conservation actions, including developing and planting white pine blister rust-resistant seedlings. Research on the propagation of rust-resistant whitebark pine seeds and seedlings is underway and strategic conservation plans are being developed.
Whitebark pine is frequently the first conifer to become established after disturbances like wildfires and subsequently stabilizes soils and regulates runoff. Snow will drift around whitebark pine trees, thereby increasing soil moisture, modifying soil temperatures, and holding soil moisture later into the season. Whitebark pine frequently shade, protect, and slow the progression of snowmelt, essentially reducing spring flooding at lower elevations. Whitebark pine also provides important, highly nutritious seeds for numerous birds and mammals.
Whitebark pine is a slow-growing, long lived tree with a life span of upwards of 500 years and sometimes over 1,000 years. Because whitebark pine seeds cannot be wind-disseminated, primary seed dispersal occurs almost exclusively by Clark's nutcrackers. Consequently, Clark's nutcrackers facilitate whitebark pine regeneration and influence its distribution and population structure through their seed caching activities.
The Service made the determination in response to a petition filed on December 9, 2008, by the Natural Resources Defense Council. The Service completed an initial review in July 20, 2010, and concluded that the petition contained substantial information supporting a full study of the whitebark pine status.
The Service has completed a comprehensive review -- known as a 12 month finding -- and determined that there is sufficient scientific and commercial data to propose listing the species throughout its range. However, the Service is precluded from beginning work immediately on a listing proposal because its limited resources must be devoted to other, higher priority actions. The Service has assigned the whitebark pine a listing priority number of 2, which means that the threats are imminent and of high magnitude.
A copy of the finding and other information about whitebark pine is available at http://www.fws.gov/mountain-prairie/species/plants/whitebarkpine