Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 UU3, UK.
BMC Ecol. 2012 Jul 30;12:14. doi: 10.1186/1472-6785-12-14.
Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse.
Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species.
Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.
理论表明，生物多样性可以通过两种主要机制来缓冲干扰和环境变异性：首先，通过补偿过程减少生态系统功能的时间方差，从而产生稳定作用；其次，通过选择表现更好的物种来提高群落响应水平，从而产生增强作用。生物多样性稳定作用的经验证据比比皆是，而生物多样性增强作用的实验证实却很少。
在这里，我们测试了不同环境条件（恒定温度与波动温度）对细菌生物多样性-生态系统功能关系的影响。我们表明，由于个别物种性能的提高，物种丰富度对生态系统功能的积极影响会因温度波动的增强而增强。
我们的结果为增强作用提供了证据，并表明，朝着功能主导物种的选择可能有利于在更具变异性的条件下维持生态系统功能。
