Historic and Current Conditions of Southwestern Grasslands

Abstract

Southwestern grasslands today share general differences from their pre-Euro-American settlement conditions. With few exceptions, grasslands--whether in the desert, prairie, or mountains--were, prior to non-Indian settlement, more diverse in plant and animal species composition, more productive, more resilient, and better able to absorb the impact of disturbances. Southwestern grasslands today are missing the elements of disturbance regimes that kept them functioning in the prelivestock period. Such interruptions include human activities leading to loss of palatable plant species and keystone grazers such as the buffalo and prairie dog. The loss of most fire events resulted in the accelerated loss of soil from wind and water erosion, including loss of the highest productivity sites from gully formation. Soil changes also include loss of soil pore space through compaction, decrease of soil organic matter, retention of surface water, and nutrient cycling processes whether permanent or temporary. The result is a loss of large-scale connectivity by isolating grasslands through urbanization and other anthropogenic influences.Individual papers from this publication

Parent Publication

• Assessment of grassland ecosystem conditions in the Southwestern United States. Vol. 1

Citation

Fletcher, Reggie; Robbie, Wayne A. 2004. Historic and Current Conditions of Southwestern Grasslands. In: Finch, Deborah M., Editor. 2004. Assessment of grassland ecosystem conditions in the Southwestern United States. Volume 1. Gen. Tech. Rep. RMRS-GTR-135-vol. 1. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 120-129