White spruce demography and herbivory by snowshoe hares measured along elevational gradients in Denali National Park II - Sub Plot Data

Treelines in Alaska are advancing in elevation and latitude because of climate warming, which is expanding the habitat available for boreal wildlife species, including snowshoe hares (Lepus americanus). Snowshoe hares are already present in tall shrub communities beyond treeline and are the main browser of white spruce (Picea glauca), the dominant tree species at treeline in Alaska. We investigated the processes involved in a 'snowshoe hare filter' to white spruce establishment near treeline in Denali National Park. We hypothesized that surrounding vegetation would influence the likelihood of spruce being browsed by hares. Therefore, at each plot we estimated ramet density for all associated woody vegetation using one square-meter subplots. Within these subplots we also counted the total number of hare fecal pellets found on the ground.