APPLICATION AND PARTIAL VALIDATION OF A HABITAT MODEL FOR MOOSE IN THE LAKE SUPERIOR REGION

Abstract

A modified version of the dormant-season portion of a Habitat Suitability Index (HIS) model developed for assessing moose (Alces alces) habitat in the Lake Superior Region was incorporated in a Geographic Information System (GIS) for 490 km² of Minnesota’s Superior National Forest. Moose locations (n = 235) were plotted during aerial surveys conducted in December 1988 and January 1990-1991. Dormant-season forage and cover quality for 1,000-m, 500-m, and 200-m radii plots around random points and moose locations were compared using U.S. Forest Service stand examination data. Cover quality indices were lower than forage quality indices within all plots. The median value for the average cover quality index was greater (P = 0.003) within 200-m plots around cow moose then for plots around random points for the most severe winter of this study. The proportion of highest-quality winter cover, such as mixed stands dominated by mid-age class white spruce (Picea glauca) and balsam fir (Abies lasiocarpa), was greater within 500-m and 200-m plots around calf moose than within similar plots around random points during the two most severe winters. These results indicate that suboptimum ratings of winter habitat quality used in the GIS dormant-season forage > 100 m from cover, as suggested in the original HSI model, are reasonable. Integrating the habitat model with forest stand data using a GIS permitted analysis of moose habitat within a relatively large geographic area. Simulation of habitat quality indicated a potential shortage of late-winter cover in the study area. The effects of forest management actions on moose habitat quality can be simulated without collecting additional data.