Spatial Modeling of Change in Rocky Mountain Grasslands

University Of Wyoming, Laramie WY

Investigators

Abstract

Grasslands are declining throughout the United States due to cultivation, development, and other land uses. Mountain grasslands in the arid West cover hundreds of thousands of hectares, and provide key forage for livestock and wildlife as well as recreational opportunities and homesites for people. Recent national assessments suggest that mountain grasslands may be endangered due to non-sustainable land uses, but little information is available. Some evidence suggests that mountain grasslands are declining in extent due to tree invasion and development, and are being degraded by invasion of non-native species. Yet, this evidence of change is not based on landscape-scale, systematic spatial analysis and causes of changes to mountain grasslands remain poorly understood. This research project focuses on mountain grasslands in the San Juan Mountains in southwestern Colorado. The researchers will use original land survey records, repeat aerial photography, repeat ground photography, field sampling, and GIS to document and map changes to grasslands in this mountain range. Key questions that will be addressed include the following: Has mountain grassland area declined or increased since EuroAmerican settlement? If grassland area has changed, are changes concentrated in particular geographic settings? If grassland area has changed, are the changes related to particular land uses or climatic change? Using GIS-based spatial modeling, which grassland areas are predicted to be most vulnerable to further change? The goal of the project is to identify how land uses are affecting mountain grasslands with the aim of maintaining grassland productivity and biological diversity while sustaining human uses. The project will provide data, maps, and spatial models that will aid policy formulation by agencies and community groups. Data will be incorporated into online planning databases and vegetation data archives. The use of these data will be encouraged through news releases, interviews, and public presentations.