Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
INRA, UMR 1391 ISPA, Bordeaux Sciences Agro, Villenave-d'Ornon, France.
Nature. 2018 May;557(7707):710-713. doi: 10.1038/s41586-018-0138-7. Epub 2018 May 23.
Biodiversity loss can heavily affect the functioning of ecosystems, and improving our understanding of how ecosystems respond to biodiversity decline is one of the main challenges in ecology. Several important aspects of the longer-term effects of biodiversity loss on ecosystems remain unresolved, including how these effects depend on environmental context. Here we analyse data from an across-ecosystem biodiversity manipulation experiment that, to our knowledge, represents the world's longest-running experiment of this type. This experiment has been set up on 30 lake islands in Sweden that vary considerably in productivity and soil fertility owing to differences in fire history. We tested the effects of environmental context on how plant species loss affected two fundamental community attributes-plant community biomass and temporal variability-over 20 years. In contrast to findings from artificially assembled communities, we found that the effects of species loss on community biomass decreased over time; this decrease was strongest on the least productive and least fertile islands. Species loss generally also increased temporal variability, and these effects were greatest on the most productive and most fertile islands. Our findings highlight that the ecosystem-level consequences of biodiversity loss are not constant across ecosystems and that understanding and forecasting these consequences necessitates taking into account the overarching role of environmental context.
生物多样性的丧失会严重影响生态系统的功能，而提高我们对生态系统如何应对生物多样性下降的理解是生态学的主要挑战之一。生物多样性丧失对生态系统的长期影响的几个重要方面仍未得到解决，包括这些影响如何依赖于环境背景。在这里，我们分析了来自一个跨生态系统生物多样性操纵实验的数据，据我们所知，这是此类实验中持续时间最长的一次。该实验在瑞典的 30 个湖泊岛屿上进行，这些岛屿由于火灾历史的不同，在生产力和土壤肥力方面存在很大差异。我们测试了环境背景对植物物种丧失如何影响两个基本群落属性——植物群落生物量和时间变异性——的影响，时间跨度为 20 年。与人工组装群落的研究结果相反，我们发现，随着时间的推移，物种丧失对群落生物量的影响会减弱；这种减弱在生产力和肥力最低的岛屿上最为明显。物种丧失通常也会增加时间变异性，而且这些影响在生产力和肥力最高的岛屿上最为显著。我们的研究结果表明，生物多样性丧失对生态系统的影响在不同的生态系统中并非是一成不变的，理解和预测这些后果需要考虑环境背景的主导作用。
