高寒草地生态系统生产力维持和提高的关键过程及其机理研究

Degradation of alpine grassland ecosystems and climate change are the most serious issues on the Tibetan plateau now. Four alpine grasslands with different land uses and degradation conditions (i.e. no grazing, moderate grazing, heavy and extreme degratations) will be used as our enperimental platforms under different treatments of moderate grazing, nutrient and water additions, and grazing with warming. The project will detemine the effects of temperature, water or rainfall, nutrients and species composition or diversity on maintance and improvement of plant productivity using some related techniques of field survey, isotope, Li-cor6400 and Li-cor8100.In particular, it will reveal the relationships between plant diversity especially root diversity and its niche complementary and plant productivity and the relationships how to vary with resource availbility. The responses and adapatations of plant species and functinoal groups to grazing and warming will be researched. The fundamental data and theorical-applications will be provided about how to balance the function of plant production and environmental conservation for the alpine grasslands in the region based on the project.

青藏高原目前面临的最大环境问题就是高寒草地生态系统的退化和气候变化。因此，如何维持和提高高寒草地植物生产力水平是我们急需解决的科学和实践问题。该项目针对利用方式和退化程度不同的4种高寒草地（自然状态、适度放牧、严重退化和极度退化草地），利用野外样带调查和控制试验平台（资源添加、物种变化、放牧和增温试验平台），应用常规群落学调查、同位素标记、光合和土壤呼吸测定以及室内分析等技术，研究4种主要驱动因子（温度、水分、养分、植物组成等）独立及其交互作用对植物生产力和生态系统固碳潜力的影响，系统探讨高寒草地生产力维持和提高的措施及其机理；阐明植物多样性特别是根系多样性和生态位分化与生产力之间的关系、及其响应和反馈不同资源有效性变化的规律；揭示高寒草甸主要植物和植物类群对适度放牧和气候变化（温度或水分）的适应性策略和机理；为提高高寒草地生态系统的生产－生态功能提供基础数据和理论基础。