生物多样性与生态系统功能的关系是当前生态学领域的重要科学问题。因为人类活动在不同的尺度上正改变地球表面的生物多样性格局，而这些变化在不同的时、空尺度上影响生态系统的功能。以往的研究更多集中探讨较单一的物种丰富度-生产力关系，缺少在不同组织层次上研究各种多样性(物种丰富度、物种多度、功能多样性、功能组成组成等)对多种生态系统功能影响的研究。在全球变化背景下，综合研究人类活动对生物多样性和多生态系统功能的影响尤为关键。本项目拟在内蒙古典型草地生态系统开展氮沉降、放牧和刈割的实验，研究其对不同组织层次的植物多样性的影响，以及对生态系统过程(生产力、分解、呼吸、氮矿化和碳固存等)的影响。本项目将对深入了解当前内蒙古高原草地植被群落组成变化及关键生态系统过程的影响，有重要的科学意义。

Humans are altering the Earth's biodiversity through a variety of activities that increase species diversity loss or species invasions from local to global scale. The changes of the Earth's biodiversity cause wide concern for they have a strong potential to ecological processes or ecosystem functions. Scientific community has come to a broad consensus on the relationship between biodiversity and ecosystem functioning. However, many ecological observations and experiments focus on simple species richness-productivity relationships, rather than other complex ecosystem processes and ecosystem functions which depend greatly on biodiversity at different organization levels, such as species richness, species abundance, species identity and functional diversity. Human activities can modify all of the above factors. Further progress will require knowledge about how human activities affect ecological communities and ecosystem processes. We will use experiments to examine potential impacts of two human activities (N deposition, grazing and mowing,) on biodiversity and ecosystems processes (i.e., productivity, litter decomposition, respiration, carbon and nitrogen cycles) in temperate Inner Mongolia grassland.