State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin 130117, China.
School of Environmental and Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK.
Sci Total Environ. 2024 Oct 20;948:174945. doi: 10.1016/j.scitotenv.2024.174945. Epub 2024 Jul 21.
Microplastic (MP) pollution can exert significant pressure on soil ecosystems, however, the interactive effects of MPs on soil bacterial, fungal and protist communities remains poorly understood. Soil macrofauna, such as earthworms, can be directly affected by MPs, potentially leading to a range of feedbacks on the soil microbial community. To address this, we conducted a microcosm experiment to examine the effects of conventional (i.e., polyethylene, polystyrene) and biodegradable MPs (i.e. PBAT, polylactic acid) on the structure of the soil bacterial, fungal, and protist communities in the presence or absence of earthworms. We found that MP contamination negatively affected the diversity and composition of soil microbial and protist communities, with smaller-sized conventional MPs having the most pronounced effects. For example, compared with the unamended control, small-sized polyethylene MPs both significantly reduced the Shannon diversity of soil bacteria, fungi, and protist by 4.3 %, 37.0 %, and 9.1 %, respectively. Biodegradable MPs increased negative correlations among bacteria, fungi, and protists. However, earthworms mitigated these effects, enhancing the diversity and altering the composition of these communities. They also increased the niche width and stability of the soil microbial food web network. Our study indicated that earthworms help attenuate the response of soil microorganisms to MPs stress by influencing the diversity and composition of soil microorganisms and soil physicochemical properties and underscores the importance of considering macrofauna in MPs research.
微塑料 (MP) 污染会对土壤生态系统造成巨大压力，然而，MP 对土壤细菌、真菌和原生动物群落的相互作用影响仍知之甚少。土壤大型动物，如蚯蚓，可以直接受到 MPs 的影响，可能会对土壤微生物群落产生一系列反馈。为了解决这个问题，我们进行了一个微宇宙实验，研究了在有或没有蚯蚓的情况下，常规 MPs（即聚乙烯、聚苯乙烯）和可生物降解 MPs（即 PBAT、聚乳酸）对土壤细菌、真菌和原生动物群落结构的影响。我们发现，MP 污染会对土壤微生物和原生动物群落的多样性和组成产生负面影响，较小尺寸的常规 MPs 影响最为显著。例如，与未添加对照相比，小尺寸的聚乙烯 MPs 分别显著降低了土壤细菌、真菌和原生动物的香农多样性 4.3%、37.0%和 9.1%。可生物降解的 MPs 增加了细菌、真菌和原生动物之间的负相关性。然而，蚯蚓减轻了这些影响，提高了这些群落的多样性并改变了它们的组成。它们还增加了土壤微生物食物网网络的生态位宽度和稳定性。我们的研究表明，蚯蚓通过影响土壤微生物的多样性和组成以及土壤理化性质，有助于减轻土壤微生物对 MPs 胁迫的反应，强调了在 MPs 研究中考虑大型动物的重要性。
