Environmental Studies Department, University of California, Santa Cruz, CA 95064, USA.
Proc Natl Acad Sci U S A. 2010 Jan 26;107(4):1443-6. doi: 10.1073/pnas.0906829107. Epub 2010 Jan 4.
Society places value on the multiple functions of ecosystems from soil fertility to erosion control to wildlife-carrying capacity, and these functions are potentially threatened by ongoing biodiversity losses. Recent empirically based models using individual species' traits suggest that higher species richness is required to provide multiple ecosystem functions. However, no study to date has analyzed the observed functionality of communities of interacting species over multiple temporal scales to assess the relationship between biodiversity and multifunctionality. We use data from the longest-running biodiversity-functioning field experiment to date to test how species diversity affects the ability of grassland ecosystems to provide threshold levels of up to eight ecosystem functions simultaneously. Across years and every combination of ecosystem functions, minimum-required species richness consistently increases with the number of functions considered. Moreover, tradeoffs between functions and variability among years prevent any one community type from providing high levels of multiple functions, regardless of its diversity. Sustained multifunctionality, therefore, likely requires both higher species richness than single ecosystem functionality and a diversity of species assemblages across the landscape.
社会重视生态系统的多种功能，从土壤肥力到侵蚀控制再到承载野生动物的能力，而这些功能正受到生物多样性持续丧失的潜在威胁。最近基于个体物种特征的经验模型表明，需要更高的物种丰富度来提供多种生态系统功能。然而，迄今为止，没有研究分析过多个时间尺度上相互作用物种群落的观测功能，以评估生物多样性和多功能性之间的关系。我们使用了迄今为止最长的生物多样性-功能实地实验的数据，以测试物种多样性如何影响草原生态系统提供多达八种生态系统功能的阈限水平的能力。跨年份和每个生态系统功能的组合，所需的最小物种丰富度随着所考虑的功能数量而持续增加。此外，功能之间的权衡和年份之间的可变性阻止了任何一种群落类型提供多种功能的高水平，无论其多样性如何。因此，持续的多功能性可能既需要比单一生态系统功能更高的物种丰富度，也需要在景观上具有多样性的物种组合。
