WILD UNGULATE USE OF AREAS IN SOUTHWESTERN MONTANA AFTER FOURTEEN YEARS OF NATURAL RECOVERY FROM SMELTER IMPACTS

摘要

During 1994, fourteen years alter the closure of the Anaconda smelters in southwestern Montana, two seasonal wild ungulate focal pellet group surveys were conducted along stratified random belt transects within three areas in close proximity to the smelters and at a more distant reference area. Vegetation patterns on the proximal sites had been altered by emissions during the 96 years of continuous smelter operation. The densities of mule deer (Odocoileus hemionus hemionus) and Shiras moose (Alces alces shiras) droppings on all of the affected areas were either greater, or no different than on the reference area. Seasonal dropping densities of Rocky Mountain elk (Cervus elaphus nelsoni) on the affected area farthest removed from human activities, were either significantly greater or no different than on the reference area. On the two affected areas closest to human activities, elk dropping densities were significantly lower than on the reference area in three of the four comparisons. Thirty-three percent of the ANOVA comparisons of seasonal dropping densities on the affected areas were significantly greater than on the reference area, 50 percent were not significantly different, and 17 percent were significantly less. The median horizontal diversity index of land cover types was greater (95 percent CI) on the affected areas than on the reference site. The mosaic of seral communities that has developed on the affected areas since closure of the smelter appears to have produced levels of big game use which are comparable to those on the reference area, except where elk are influenced by human activities.