MODELING THE POTENTIAL SPATIAL-DISTRIBUTION OF BEEF-CATTLE GRAZING USING A GEOGRAPHIC INFORMATION-SYSTEM

Data regarding grazing utilization in the western United States are ty pically compiled within administrative boundaries (e.g. allotment, pas ture). For large areas, an assumption of uniform distribution is seldo m valid. Previous studies show that vegetation type, degree of slope, and distance from water largely determine the distribution of livestoc k. We demonstrate how range managers can use Boolean logic and a Geogr aphic Information System (GIS) to develop models that predict which ar eas beef cattle are most and least likely to graze. The models show th at approximately 60% of the state of Oregon has potential for rangelan d grazing. The results compare favorably with the 1992 census of beef cattle. (C) 1998 Academic Press Limited.