The Climatic Implications of Lake Level Expansion in the Mackenzie Bison Sanctuary, Fort Providence, Northwest Territories

Remotely sensed data indicates that lake expansion north of Fort Providence, Northwest Territories, is statistically significant, potentially contributing to wood bison (Bison bison athabascae) migrating beyond the Mackenzie Bison Sanctuary. The Mackenzie herd is one of the few remaining populations not infected by bovine brucellosis (Brucella abortus) and tuberculosis (Mycobacterium bovis). Interaction with nearby infected herds could introduce widespread infection. Lake expansion is often driven by changes in climate, however climate records for this region are lacking. Dendrochronology can be used to examine longer-term climate. Climate was reconstructed using nine white spruce (Picea glauca) chronologies. Correlations were highest between the chronologies and the Palmer Drought Severity Index, which show climate variability has increased within the study area since 1915. Remote sensing results correlate with positive phases of the July-October Pacific North American pattern, however the freezing date of the active layer may provide a better understanding of water level fluctuations.