Sierra Nevada Aquatic Research Laboratory

13 Aug, 10 AM - 27 Aug, 10 AM

The purpose of this project is to examine the influence of grazing on community composition in California sagebrush vegetation. Previous surveys in other states have revealed strong differences between sites in response to livestock exclusion, yet the literature on these patterns in California is poor. Surveys of cold desert rangelands in the Great Basin frequently depict current sagebrush communities as stable and dominant over long periods of time, as observed following removal of grazing. There is considerable variation in responses to grazing release between different regions and grazing regimes, however, from no response to substantial changes in density or cover of shrubs and/or perennial grasses. A test of ecological indictors used to gauge rangeland health also varied in their effectiveness at different locations, emphasizing the importance of location-specific evaluation of grazing effects. Despite this inherent variability, relatively few studies have investigated Great Basin desert rangelands along the eastern Sierra Nevada in California, leading to considerable uncertainty about their responses to grazing and successional trajectories following grazing removal. In this project, I propose to investigate the question: How has the removal of livestock grazing affected the species richness, diversity and composition in sagebrush communities in the eastern Sierra? This project will add necessary information to the literature about sagebrush communities along the eastern Sierra Nevada and their responses to grazing. Given the high degree of variation between other sagebrush sites, specific knowledge may be necessary to understand responses to disturbance and to predict future changes in composition. The results of this study will also allow local land managers to assess the trajectory of vegetation patterns with cattle removal, including management of SNARL. The set-up of the NRS reserve within the larger landscape context provides a unique opportunity to examine these changes and make predictions following changes in management. Additionally, since many researchers have documented a strong relationship between cheatgrass invasion and fire frequency, it will be important to understand the value of cattle grazing for both directly controlling the non-native grass and ultimately buffering the landscape from fires by reducing fuel. Despite the fact that higher elevations are typically more resistant to cheatgrass invasion, current warming trends may expand the range of B. tectorum. Therefore, understanding the influence of current management on its distribution at high elevations may be critical. Overall, I hope that this project will inform knowledge of plant communities and distributions on the reserve and enable predictions about future composition in ungrazed and grazed California sagebrush steppe.

Visit #28289 @Sierra Nevada Aquatic Research Laboratory

Approved

Under Project # 25133 | Research

Grazing impacts on Great Basin sagebrush communities in eastern California

faculty - University of California, Santa Barbara

Reservation Members(s)

Karen Stahlheber Aug 13 - 27, 2012 (15 days)
Karen Stahlheber Aug 13 - 27, 2012 (15 days)

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