Grassland degradation is a global concern, affecting not only wild species and pastoralists who rely on healthy grasslands for their survival, but also non-local people who suffer from resultant hydrological disturbances, dust storms, commodity scarcity, and social consequences of uprooted people. Livestock grazing is the dominant form of land use in Central Asia, and pastures of the Tibetan highlands are located upstream and upwind of roughly 40 percent of the world's human population. Grasslands on the Tibetan plateau usually are described as increasingly degraded. Causes for this grassland degradation are variously attributed to over-stocking of livestock, poor livestock management, historical-cultural factors, alteration of land-tenure arrangements, rapid changes in socioeconomic systems, climate change, and excessive herbivory and soil disturbance from wildlife. Prior research has yet to provide clear support for any putative causative agents, however, and previous studies have not examined interactions and complexity among these factors. As a result, policy choices to reduce or reverse grassland degradation often are made without a clear rationale and are based more on prejudice or convenience than evidence of their effectiveness. This interdisciplinary project will examine multiple correlates of grassland status and trends simultaneously, using replicated measurements at permanent plots in a multi-strata design, measuring the strength of evidence for various competing hypotheses. The investigators will link ecological measurements directly to current and recent historical actions by pastoralists, which in turn are affected by cultural norms, economic incentives, and policies of central and provincial governments. In addition to biophysical attributes of each site, livestock density and pasture usage patterns will be quantified. Each site also will be described by the particular grazing strategy employed by the pastoralist managing it, and that strategy, in turn, will be related to the complex of economic and policy incentives and historical determinants that pastoralists face. These data will be used to develop models that link broad historical, policy, economic, and cultural factors to local grassland conditions as mediated by the agency of individual pastoralists. The models can also be used to evaluate the implications of different policy interventions.
This project will deepen basic understanding of the complex interactions involving geophysical, biological, social, and policy factors and feedback systems that affect grassland status. Because multiple factors affect grasslands simultaneously and interactions are critical, the interdisciplinary, the systems-approach adopted by this project is fundamental. Enhanced understanding of this socioecological system will provide important input for policies on grassland restoration, biodiversity, and economic development in arid ecosystems worldwide. In addition to the education and training of students, the project will train a number of Tibetan field assistants, and the researchers will coordinate their work closely with local and provincial grassland and forestry officials. Direct collaboration with Chinese scientists and officials as well as facilitated workshops will enable research results to be understood by policy makers. Direct interactions with local pastoralists will allow immediate, practical applications of project results. This project is supported by the NSF Dynamics of Coupled Natural and Human Systems (CNH) Program.
