Data from: Interactive effects of climate change and biodiversity loss on ecosystem functioning

Climate change and biodiversity loss are expected to simultaneously affect ecosystems, however research on how each driver mediates the effect of the other has been limited in scope. The multiple stressor framework emphasizes non-additive effects, but biodiversity may also buffer the effects of climate change, and climate change may alter which mechanisms underlie biodiversity-function relationships. Here, we performed an experiment using tank bromeliad ecosystems to test the various ways that rainfall changes and litter diversity may jointly determine ecological processes. Litter diversity and rainfall changes interactively affected multiple functions, but how depended on the process measured. High litter diversity buffered the effects of altered rainfall on detritivore communities, evidence of insurance against impacts of climate change. Altered rainfall affected the mechanisms by which litter diversity influenced decomposition, reducing the importance of complementary attributes of species (“complementarity effects”), and resulting in an increasing dependence on the maintenance of specific species (“dominance effects”). Finally, altered rainfall conditions prevented litter diversity from fuelling methanogenesis, because such changes in rainfall reduced microbial activity by 58%. Together, these results demonstrate that the effects of climate change and biodiversity loss on ecosystems cannot be understood in isolation and interactions between these stressors can be multifaceted.气候变化与生物多样性丧失预计将同时影响生态系统，但针对二者如何相互介导对方影响的研究，其研究范围仍较为有限。多重胁迫框架（multiple stressor framework）强调非加和效应（non-additive effects）的存在，但生物多样性亦可缓冲气候变化的影响，而气候变化则可能改变支撑生物多样性-生态系统功能关系（biodiversity-function relationships）的核心机制。本研究利用储水凤梨微生态系统（tank bromeliad ecosystems）开展实验，旨在探究降雨变化与凋落物多样性如何共同调控生态过程。凋落物多样性与降雨变化对多项生态功能存在交互影响，但其作用模式因所测生态过程的不同而存在差异。高多样性凋落物可缓解降雨变化对腐食性动物群落（detritivore communities）的影响，这为抵御气候变化冲击的生态保险效应提供了实验证据。降雨变化改变了凋落物多样性调控分解过程的作用机制：其降低了物种种间互补属性的重要性（即“互补效应（complementarity effects）”），并使得生态过程愈发依赖特定物种的维持（即“优势种效应（dominance effects）”）。此外，降雨变化条件抑制了凋落物多样性驱动产甲烷作用（methanogenesis）的过程，原因在于此类降雨变化将微生物活性（microbial activity）降低了58%。综合来看，本研究结果表明，气候变化与生物多样性丧失对生态系统的影响无法孤立解读，二者作为胁迫因子的交互作用模式具有多面性。