Wang Shengnan, Barry Kathryn E, Kowalchuk George A, Eisenhauer Nico, Pan Xiaobin, Verschoor Mink R, Soons Merel B, Hautier Yann
Ecology and Biodiversity Group, Department of Biology, Utrecht University, Utrecht, the Netherlands.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
Glob Chang Biol. 2025 Aug;31(8):e70377. doi: 10.1111/gcb.70377.
Biodiversity loss and increasing drought events due to climate change threaten ecosystem stability by disrupting soil organic matter decomposition. Soil detritivores play a crucial role in mitigating this impact through the fragmentation of organic residues, enhancement of microbial activity, and modification of soil structure, ultimately regulating soil organic carbon cycling and nutrient availability. However, the interactive effects of plant diversity and extreme drought on their activity remain unknown. To investigate this, we measured soil detritivore feeding activity and its differences between soil layers in a long-term grassland experiment (2018-2023) that manipulated both plant diversity and projected precipitation patterns. The results presented here focus on two distinct periods: (1) the establishment of the experiment (2018-2022), during which all plots experienced ambient rainfall, and (2) the first year of precipitation manipulation (2023), when plots were split into drought and control treatments. During the establishment phase, we found that plant diversity increased soil detritivore feeding activity, an effect that strengthened and stabilized over time. During the first year of precipitation manipulation, we found that plant diversity increased feeding activity under both control and drought conditions, with higher activity during drought. Under control, both feeding activity and its positive relationship with plant diversity declined with soil depth. In contrast, during drought, feeding activity remained stable, and the positive effects of plant diversity increased with depth. These results suggest vertical shifts in feeding activity maintain the benefits of plant diversity for decomposition under drought. Preserving plant diversity could mitigate drought impacts on detritivore activity and soil organic matter decomposition, enhancing ecosystem resilience to climate extremes.
生物多样性丧失以及气候变化导致的干旱事件增加，通过扰乱土壤有机质分解，威胁着生态系统的稳定性。土壤食腐动物通过分解有机残体、增强微生物活性和改变土壤结构，在减轻这种影响方面发挥着关键作用，最终调节土壤有机碳循环和养分有效性。然而，植物多样性和极端干旱对其活动的交互作用仍不清楚。为了研究这一点，我们在一个长期草地实验（2018 - 2023年）中测量了土壤食腐动物的取食活动及其在不同土层间的差异，该实验同时控制了植物多样性和预计降水模式。这里展示的结果聚焦于两个不同时期：（1）实验建立期（2018 - 2022年），在此期间所有地块都经历了正常降雨；（2）降水控制的第一年（2023年），此时地块被分为干旱和对照处理。在实验建立阶段，我们发现植物多样性增加了土壤食腐动物的取食活动，且这种效应随着时间推移而增强并稳定下来。在降水控制的第一年，我们发现植物多样性在对照和干旱条件下均增加了取食活动，干旱期间的活动更高。在对照条件下，取食活动及其与植物多样性的正相关关系均随土壤深度下降。相比之下，在干旱期间，取食活动保持稳定，且植物多样性的积极影响随深度增加。这些结果表明取食活动的垂直变化维持了干旱条件下植物多样性对分解的益处。保护植物多样性可以减轻干旱对食腐动物活动和土壤有机质分解的影响，增强生态系统对极端气候的恢复力。
