Responses of Chihuahuan Desert annual plant communities to desertification and exposure to varying grazing stress.

TitleResponses of Chihuahuan Desert annual plant communities to desertification and exposure to varying grazing stress.
Publication TypeConference Paper
Year of Publication1997
AuthorsVan Zee JW, de Soyza A.G., Whitford WG
Conference NameInternational Symposium and Workshop Combating Desertification: Connecting Science with Community Action
Date PublishedMay 12-16, 1997
Conference LocationTucson, AZ
Abstract

Ephemeral or annual plant communities respond to a variety of environmental factors, including rainfall, nutrients, temperature, competition, and disturbance. Stressors such as cattle grazing can alter perennial plant communities and soil properties sufficiently to change annual plant communities. We examined density and biomass of annual plant species at sites representing historically documented desertification (a degradation gradient), grazing intensity gradients, grazing exclosures and enclosures, rangeland rehabilitation efforts, and recent fires, as well as sites representing habitats unique to the Chihuahuan Desert. Traditional community vegetation parameters such as species richness and indices of species diversity do not always effectively explain patterns in annual plant communities.   We emphasize examination of key species and micro habitat patterns when analyzing the effects of disturbance of ephemeral plant communities and include examples of how ephemeral plants respond to patchy environments in a wide range of habitats and landscape positions in Chihuahuan Desert rangelands.