Impacts of caribou on alpine vegetation communities in the north Kenai Mountains: The interaction between grazing and topography (Alaska)

The relationship between topography and snow accumulation restricts mountain caribou to areas where forage is available. High concentrations of caribou can create changes in vegetation communities. Locations of radio-collared Kenai Mountains Caribou were mapped in GIS in order to determine how topography affected caribou distribution. Vegetation along ridgelines located within and outside this herd's winter range was compared in order to determine how grazing and topography affect vegetation communities. Caribou demonstrated a strong preference for high elevations, southern exposures and close proximities to ridgelines. Cover of caribou forage lichens was significantly lower and cover of non-forage lichens was significantly higher on caribou winter range than outside it. Aspect impacted lichen cover on caribou winter range but not outside it. Proximity to ridgeline had a greater impact on lichens in caribou winter range. Management of alpine caribou herds must be based on the interactions of topography, forage availability and grazing history.