CNH: Collaborative Research: Determinants of Grassland Dynamics in Tibetan Highlands: Livestock, Wildlife, and the Culture and Political Economy of Pastoralism

草地退化是一个全球性问题，不仅影响到依赖健康草地生存的野生物种和牧民，而且影响到非当地人，他们遭受由此产生的水文扰动、沙尘暴、商品短缺和背井离乡的人造成的社会后果。 畜牧业是中亚地区土地利用的主要形式，西藏高原的牧场位于世界人口约40%的上游和上风。 青藏高原的草原通常被描述为日益退化。 造成草原退化的原因多种多样，包括牲畜放养过多、牲畜管理不善、历史文化因素、土地使用权安排的改变、社会经济制度的迅速变化、气候变化以及野生动物过度食草和土壤扰动。 然而，先前的研究尚未为任何假定的致病因子提供明确的支持，并且先前的研究尚未研究这些因素之间的相互作用和复杂性。 因此，减少或扭转草原退化的政策选择往往没有明确的理由，更多地是基于偏见或便利，而不是有效性的证据。 这个跨学科的项目将同时研究草原状况和趋势的多种相关性，在多层次设计中使用永久地块的重复测量，测量各种竞争假设的证据强度。 研究人员将把生态测量直接与牧民当前和最近的历史行动联系起来，而这些行动又受到文化规范、经济激励措施以及中央和省级政府政策的影响。 除了每个地点的生物物理属性外，还将量化牲畜密度和牧场使用模式。 每一个地点还将按照管理该地点的牧民所采用的特定放牧战略来描述，而这种战略又将与牧民所面临的复杂的经济和政策激励措施以及历史决定因素有关。 这些数据将用于开发模型，将广泛的历史，政策，经济和文化因素与当地草原条件联系起来，由个人牧民代理。 该项目将加深对影响草地状况的地球物理、生物、社会和政策因素以及反馈系统之间复杂相互作用的基本理解。 由于多种因素同时影响草地，相互作用是至关重要的，因此该项目采用的跨学科、系统方法是至关重要的。 加强对这一社会生态系统的了解将为全球干旱生态系统的草原恢复、生物多样性和经济发展政策提供重要投入。 除了对学生进行教育和培训外，该项目还将培训一批西藏野外助理，研究人员将与当地和省级草原和林业官员密切协调工作。 与中国科学家和官员的直接合作以及促进研讨会将使政策制定者能够了解研究成果。 与当地牧民的直接互动将使项目成果能够立即得到实际应用。 该项目由NSF耦合自然和人类系统动力学（CNH）计划支持。

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.