Experimental Plant Ecology, Ernst-Moritz-Arndt University Greifswald, D-17487, Greifswald, Germany.
Plant Ecology, BayCEER, University of Bayreuth, 95440, Bayreuth, Germany.
Ecol Lett. 2017 Nov;20(11):1405-1413. doi: 10.1111/ele.12848. Epub 2017 Sep 20.
Biodiversity can buffer ecosystem functioning against extreme climatic events, but few experiments have explicitly tested this. Here, we present the first multisite biodiversity × drought manipulation experiment to examine drought resistance and recovery at five temperate and Mediterranean grassland sites. Aboveground biomass production declined by 30% due to experimental drought (standardised local extremity by rainfall exclusion for 72-98 consecutive days). Species richness did not affect resistance but promoted recovery. Recovery was only positively affected by species richness in low-productive communities, with most diverse communities even showing overcompensation. This positive diversity effect could be linked to asynchrony of species responses. Our results suggest that a more context-dependent view considering the nature of the climatic disturbance as well as the productivity of the studied system will help identify under which circumstances biodiversity promotes drought resistance or recovery. Stability of biomass production can generally be expected to decrease with biodiversity loss and climate change.
生物多样性可以缓冲生态系统功能对极端气候事件的影响，但很少有实验明确对此进行测试。在这里，我们首次进行了多地点生物多样性与干旱处理的实验，在五个温带和地中海草原地点检验干旱抵抗能力和恢复能力。由于实验性干旱（通过降雨排除使标准局部极端情况持续 72-98 天），地上生物量产量下降了 30%。物种丰富度不影响抵抗能力，但促进了恢复。在低生产力群落中，物种丰富度仅对恢复产生积极影响，最多样化的群落甚至出现了超补偿。这种积极的多样性效应可能与物种响应的非同步性有关。我们的结果表明，一种更加依赖情境的观点，同时考虑气候干扰的性质和研究系统的生产力，将有助于确定在何种情况下生物多样性可以促进干旱抵抗能力或恢复能力。随着生物多样性的丧失和气候变化，生物量生产的稳定性通常预计会降低。
