Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada.
Nature. 2011 Aug 10;477(7363):199-202. doi: 10.1038/nature10282.
Biodiversity is rapidly declining worldwide, and there is consensus that this can decrease ecosystem functioning and services. It remains unclear, though, whether few or many of the species in an ecosystem are needed to sustain the provisioning of ecosystem services. It has been hypothesized that most species would promote ecosystem services if many times, places, functions and environmental changes were considered; however, no previous study has considered all of these factors together. Here we show that 84% of the 147 grassland plant species studied in 17 biodiversity experiments promoted ecosystem functioning at least once. Different species promoted ecosystem functioning during different years, at different places, for different functions and under different environmental change scenarios. Furthermore, the species needed to provide one function during multiple years were not the same as those needed to provide multiple functions within one year. Our results indicate that even more species will be needed to maintain ecosystem functioning and services than previously suggested by studies that have either (1) considered only the number of species needed to promote one function under one set of environmental conditions, or (2) separately considered the importance of biodiversity for providing ecosystem functioning across multiple years, places, functions or environmental change scenarios. Therefore, although species may appear functionally redundant when one function is considered under one set of environmental conditions, many species are needed to maintain multiple functions at multiple times and places in a changing world.
生物多样性在全球范围内迅速减少，人们普遍认为这会降低生态系统的功能和服务。然而，目前还不清楚维持生态系统服务需要生态系统中少数还是多数物种。有人假设，如果考虑到多次、多个地点、多种功能和多种环境变化，大多数物种都会促进生态系统服务；但是，以前的研究没有综合考虑所有这些因素。在这里，我们发现，在 17 项生物多样性实验中研究的 147 种草原植物物种中，有 84%至少有一次促进了生态系统功能。不同的物种在不同的年份、不同的地点、不同的功能和不同的环境变化情景下促进了生态系统功能。此外，在多年内提供一种功能所需的物种与在一年内提供多种功能所需的物种并不相同。我们的研究结果表明，与那些只考虑在一组环境条件下促进一种功能所需的物种数量的研究相比（1），或（2）分别考虑生物多样性在多年、多个地点、多种功能或环境变化情景下对提供生态系统功能的重要性的研究相比，维持生态系统功能和服务所需的物种数量可能会更多。因此，尽管在考虑一种功能和一组环境条件时，物种可能在功能上显得冗余，但在不断变化的世界中，需要许多物种来维持多个功能在多个时间和地点的存在。
