Abstract
Grazing by domestic livestock is authorized in Glen Canyon National Recreation Area and continues on about 80 percent of the park. Concern over competing land uses has generated considerable interest in the direct and indirect effects of grazing on vegetation, small mammal, and avian community structure and function. The primary objectives of this study are: 1. to identify and evaluate the abiotic and biotic factors influencing the structure and species composition of relict and grazed pinyon-juniper and blackbrush/lndian ricegrass communities, and 2. to select, refine and validate a system that can be used to field monitor condition and trend of relict and grazed communities. It is the goal of this project to develop a method of qualitatively assessing and monitoring community condition and trend using a combination of quantitative community attributes which are sensitive to grazing by domestic livestock; and which can be easily implemented and interpreted within the management objectives of GCNRA.