The status of whitebark pine (Pinus albicaulis), a foundation and keystone species and a pioneer establisher at alpine treeline, is threatened by the invasive and exotic fungal pathogen (Cronartium ribicola) that causes white pine blister rust in five-needled pines. Originally thought to be limited to moderate environments, the disease is now found extensively throughout colder and dryer regions east of the Continental Divide, including alpine treeline. My research objective was to determine how blister rust infection of treeline whitebark pine varies across Glacier National Park. I present findings from field sampling conducted in July 2008 in Glacier National Park, Montana. Thirty plots were randomly placed at 6 different treeline study sites on the eastern slopes of the Continental Divide. Vegetative and geomorphic characteristics, along with presence/absence and level of blister rust intensity, were detailed within each plot. Vegetation measurements included conifer composition, tree island dimensions and windward growth patterns, evidence and intensity of blister rust, as well as shelter type. Field-measured topographic characteristics included elevation, aspect, and slope. In addition, high resolution GPS-derived DEMs were created at each plot in order to model the land surface and calculate detailed environmental variables in a GIS. Environmental and blister rust intensity variables were used to determine spatial correlates of blister rust infection at treeline. The resulting blister rust prediction model (P < 0.001, F(4,25) = 6.79, R2 = 0.52, Adjusted R2 = 0.44) suggests that areas exhibiting increased wind speed, northwest facing slopes, high flow accumulation rates, and close proximity to perennial streams have a higher likelihood of blister rust intensity, specifically total canker density. Results of this research may contribute to the understanding of the dynamics of this disease, and prove useful in whitebark ecosystem management and conservation. / Master of Science

Whitebark pine (Pinus albicaulis) is a foundation and keystone species at alpine treelines of the northern Rocky Mountains and is threatened by the fungus white pine blister rust (Cronartium ribicola). This disease affects all five-needled white pines, but has caused particularly widespread mortality in whitebark pine. Objectives of this research were: 1) to characterize the landscape structure of the treeline study sites at Divide Mountain in Glacier National Park and at Wyoming Creek in the Beartooth Mountains of Montana using landscape metrics and fieldwork; 2) to determine the frequency of blister rust infection of whitebark pine trees and determine if landscape pattern is correlated with higher infection rates; and 3) to characterize the climate at alpine treeline. I used both field surveys and subsequent statistical analysis to meet these objectives. Field data collection included detailed surveys of blister rust infection of treeline whitebark pine and characterization of landscape cover type in a combined total of 60 quadrats, positioned at the study sites using a random sampling scheme stratified by aspect. Landscape analysis of metrics such as patch area, proximity and contagion were generated in FRAGSTATS software and ArcGIS. Spearman's rank correlation analysis found significant correlations between tree island patch size, patch perimeter, and percent of landscape and blister rust infection intensity at both study sites. These findings support previous research involving the relationship between patch area and blister rust infection rates and contribute to the field of landscape ecology by understanding what other landscape metrics are significant in invasive disease infection patterns. / Master of Science