BIODIVERSITY''''S ECOSYSTEM FUNCTIONING: A UNITY OF BOTH QUANTITY AND QUALITY
生物多样性的生态系统功能:质与量的综合评价

The value of biodiversity is well-known, but how diversity performs its ecosystem function and provides services is less clear （Ehrlich, 1994; Grime, 1997; Wall, 2004, Xie et al., 2006 ）. In the last two decades, tremendous efforts have been devoted to investigating the biodiversity effects on ecosystem functioning （Hooper et al., 2005 ）. In most cases, particularly in grassland seeding experiments, productivity （i. e., rate of biomass production） has been used as the sole measure of ecosystem functioning, while what is being produced （i. e., the quality or product diversity） is frequently ignored. However, ecosystem functioning, like many other things in our life （e. g., the impacts of scientific papers）, is a multifaceted concept and is far more than simply productivity and should be assessed by beth quantity and quality1）. Here we call for a reevaluation of the current measures used to evaluate biodiversity＇ s ecosystem function. Although the quantitative （e. g., productivity） and qualitative （product quality） aspects may be assessed separately but their combination should be used for overall evaluation of ecosystem functioning. This is because beth quantity and quality measures are important to beth basic ecological research and land management, as we outline below.