Xi Nianxun, Chen Dongxia, Bahn Michael, Wu Hangyu, Chu Chengjin, Cadotte Marc W, Bloor Juliette M G
State Key Laboratory of Biocontrol, School of Life Sciences/School of Ecology, Sun Yat-sen University, Guangzhou 510275, China.
Department of Ecology, University of Innsbruck, 6020 Innsbruck, Austria.
Sci Adv. 2022 May 6;8(18):eabn3368. doi: 10.1126/sciadv.abn3368. Epub 2022 May 4.
Ecosystem functions are threatened by both recurrent droughts and declines in biodiversity at a global scale, but the drought dependency of diversity-productivity relationships remains poorly understood. Here, we use a two-phase mesocosm experiment with simulated drought and model oldfield communities (360 experimental mesocosms/plant communities) to examine drought-induced changes in soil microbial communities along a plant species richness gradient and to assess interactions between past drought (soil legacies) and subsequent drought on plant diversity-productivity relationships. We show that (i) drought decreases bacterial and fungal richness and modifies relationships between plant species richness and microbial groups; (ii) drought soil legacy increases net biodiversity effects, but responses of net biodiversity effects to plant species richness are unaffected; and (iii) linkages between plant species richness and complementarity/selection effects vary depending on past and subsequent drought. These results provide mechanistic insight into biodiversity-productivity relationships in a changing environment, with implications for the stability of ecosystem function under climate change.
在全球范围内，生态系统功能受到周期性干旱和生物多样性下降的双重威胁，但多样性与生产力关系对干旱的依赖性仍知之甚少。在此，我们采用两阶段的中宇宙实验，设置模拟干旱条件并构建模拟弃耕地群落（360个实验中宇宙/植物群落），以研究沿植物物种丰富度梯度土壤微生物群落的干旱诱导变化，并评估过去干旱（土壤遗留效应）与后续干旱对植物多样性-生产力关系的相互作用。我们发现：（i）干旱会降低细菌和真菌的丰富度，并改变植物物种丰富度与微生物类群之间的关系；（ii）干旱土壤遗留效应会增加净生物多样性效应，但净生物多样性效应对植物物种丰富度的响应不受影响；（iii）植物物种丰富度与互补/选择效应之间的联系因过去和后续干旱而异。这些结果为变化环境中生物多样性与生产力关系提供了机制性见解，对气候变化下生态系统功能的稳定性具有启示意义。
