State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049,China.
J Hazard Mater. 2023 Oct 5;459:132164. doi: 10.1016/j.jhazmat.2023.132164. Epub 2023 Aug 9.
Heavy metals pose significant threats to soil biota, ultimately disrupting soil micro-food web. However, no studies have yet elucidated the impact of heavy metals on soil micro-food web. In this study, we explored the response of bacteria, fungi, nematodes, and soil micro-food web along a gradient of heavy metals in an abandoned smelting-mining area. We found that bacteria responded strongly to heavy metals, whereas fungi showed greater resistance and tolerance. Nematodes responses were less apparent. With the increasing levels of heavy metal pollution, the importance of heavy metal-tolerant organisms in micro-food webs increased significantly. For instance, the keystone bacteria in soil micro-food web shifted from copiotrophic to oligotrophic types, while the keystone nematodes shifted from to bacterial-feeding (e.g., Eucephalobus) to fungal-feeding species (e.g., Ditylenchus). Additionally, elevated heavy metal concentrations increased the proportion of fungi (e.g., Mortierellomycota), intensifying their interactions with bacteria and nematodes and causing a shift from bacteria-based to fungi-based soil micro-food web. Furthermore, heavy metal contamination induced a more complex and stable soil micro-food web. Overall, we highlight the changes in soil micro-food web as a mechanism for coping with heavy metal stress. Our study provides valuable insights into how heavy metal pollution can cause shifts in soil micro-food webs and has critical implications for enhancing our understanding of the ecological consequences of environmental pollution at the ecosystem level.
重金属对土壤生物群构成重大威胁，最终扰乱土壤微型食物网。然而，目前尚无研究阐明重金属对土壤微型食物网的影响。本研究中，我们探讨了在废弃的冶炼矿区重金属梯度中，细菌、真菌、线虫和土壤微型食物网的响应。结果发现，细菌对重金属的响应较强，而真菌表现出更强的抗性和耐受性。线虫的响应不太明显。随着重金属污染水平的升高，重金属耐受生物在微型食物网中的重要性显著增加。例如，土壤微型食物网中的关键细菌从富养型转变为寡养型，而关键线虫从细菌食性（如 Eucephalobus）转变为真菌食性（如 Ditylenchus）。此外，较高的重金属浓度增加了真菌（如 Mortierellomycota）的比例，加强了它们与细菌和线虫的相互作用，并导致从以细菌为基础的土壤微型食物网向以真菌为基础的土壤微型食物网转变。此外，重金属污染诱导了更复杂和稳定的土壤微型食物网。总体而言，我们强调了土壤微型食物网的变化作为应对重金属胁迫的机制。本研究为重金属污染如何导致土壤微型食物网的变化提供了有价值的见解，并对提高我们在生态系统层面上对环境污染的生态后果的理解具有重要意义。
