Dendroecological techniques and analyses will be used to provide high-quality, temporally precise information on the ecological status of endangered whitebark pine ecosystems. This dissertation research investigates the ecology of whitebark pine communities using methods of stand dynamics and dendroecology to provide a long-term record of disturbance and stand history in diminishing whitebark pine communities in western Montana and central Idaho. Whitebark pine is a long-lived tree species found in many high elevation and subalpine forest communities of western North America. Whitebark pine is considered a keystone species in mutualistic relationships that involve Clark's nutcrackers, black bears, and grizzly bears. Twentieth century fire suppression, periodic mountain pine beetle outbreaks, and infection by white pine blister rust have led to dramatic declines in whitebark pine communities throughout the species' native range, with critical ramifications for dependent wildlife species. To better understand the dynamics of these declining communities, this project will investigate current and past stand dynamics and the synergistic effects of blister rust, fire exclusion, mountain pine beetle, and climate on changing the structure, composition, and vigor of whitebark pine communities. This project is unique for its combined emphasis on stand dynamics, disturbance regimes, and climate-forest health interactions in the northern Rocky Mountains. The researchers will (1) collect tree cores from all living and dead standing trees to obtain precise information on the disturbance regime and successional status of whitebark pine over the past five centuries, (2) quantify the age structure and assess the successional status of subalpine fir, and (3) evaluate the effects of blister rust, mountain pine beetle, and fire suppression in whitebark pine ecosystems on a landscape scale. Knowledge of the complex stand dynamics and stand history of whitebark pine ecosystems is essential to the long-term management and restoration of this declining critical species.
Whitebark pine restoration efforts must succeed in the next 15-20 years for this species to avoid extinction, which would dramatically impact wildlife species and likely destabilize fragile ecosystems in the higher elevations. The results from this research will be shared with land management agencies (such as the USDA Forest Service and the National Park Service) and conservation organizations (such as the Whitebark Pine Ecosystem Foundation). Whitebark pine tree-ring data (which will be contributed to the World Data Center for Paleoclimatology) will add needed data points to the paleoclimatic record in North America. Information gathered from this research will be integrated into programs run by the Tennessee Geographic Alliance and will be presented to a variety of audiences, including kindergarten-12th grade students, senior citizen groups, and local summer camps (YMCA).
