Landscape Assessment and Monitoring of Mountain Pine Beetle Mortality in Greater Yellowstone Ecosystem Whitebark Pine

Since 2000, USDA Forest Service Aerial Detection Surveys (ADS) and ground-based surveys indicate mountain pine beetle (MPB) outbreaks have caused catastrophic loss of whitebark pine (WBP) in the Greater Yellowstone Ecosystem (GYE). However, the full extent of the damage is unknown because of limitations to the traditional survey methods. We describe a new method aimed at quickly and cost-effectively documenting landscape conditions. The method utilizes low-flying airplane overflights, Global Positioning System (GPS), and Geographic Information System (GIS) technologies along with digital photography to categorize MPB outbreaks based on a new landscape classification scheme. We conducted a pilot study consisting of four overflights covering large portions of the Teton Wilderness, Wind River, Absaroka, Gallatin, and Beartooth mountain ranges. Results indicate our approach is a reliable and repeatable method to assess the extent and severity of MPB related WBP mortality. Significant MPB activity was documented throughout the area surveyed - only the center core of the Wind River Range, the Beartooth Plateau and Northern Gallatin Range remain in a healthy condition. A vast area of approximately 450,000 acre covering the northern Wind River Range, Southwestern Absoroka Range and the Teton Wilderness, was found to be the most heavily impacted. Here the overflights document an ecological collapse of the WBP ecosystem due to unprecedented MPB outbreaks. This pilot study provided an independent validation of previous computer simulations and corroborates the general trend indicated by US Forest Service ADS. Additionally, results extend previous information in several ways: (1) The outbreaks are outpacing computer simulations that were based on climate warming predictions. (2) Our approach identified greater mortality when compared to the ADS results. (3) Overflights were conducted in several regions of the GYE not recently or never surveyed by ADS, and therefore provide a more comprehensive documentation of MPB impact in WBP than previously available.