Liu Mengli, Wang Chong, Zhu Biao
Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China.
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Environ Sci Technol. 2023 Aug 1;57(30):11206-11217. doi: 10.1021/acs.est.3c01538. Epub 2023 Jul 20.
Soil ecosystems are under considerable pressure due to anthropogenic factors, including microplastics (MPs) pollution and drought. However, little is known about the interactive effects of MPs and drought on soil organisms, especially soil micro-food web. We conducted a microcosm experiment with MPs pollution (including two types and two sizes of MPs) and drought to investigate their interaction effects on soil microbial, protist, and nematode communities in soil micro-food web. We found that MPs significantly decreased the complexity and stability of soil micro-food web, with greater negative effects of biodegradable and smaller-sized MPs than conventional and larger-sized MPs. Drought had negative effects on soil micro-food web in the non-MPs pollution soils while increasing the complexity and stability of soil micro-food web in the MPs pollution soils. Drought increased the proportion of negative correlations between bacteria and fungi in the biodegradable MPs soils while decreasing the proportion of negative correlations between protists and nematodes in the smaller-sized MPs soils. Our study reveals that drought may alleviate the negative effects of MPs on soil micro-food web by reducing competition among lower trophic levels in the biodegradable MPs pollution soils while reducing competition among higher trophic levels in the smaller-sized MPs pollution soils.
由于包括微塑料（MPs）污染和干旱在内的人为因素，土壤生态系统面临着巨大压力。然而，关于微塑料和干旱对土壤生物，尤其是土壤微型食物网的交互作用，我们所知甚少。我们进行了一项微观实验，研究微塑料污染（包括两种类型和两种尺寸的微塑料）和干旱对土壤微型食物网中土壤微生物、原生生物和线虫群落的交互作用。我们发现，微塑料显著降低了土壤微型食物网的复杂性和稳定性，其中可生物降解的小尺寸微塑料比传统的大尺寸微塑料产生的负面影响更大。干旱对无微塑料污染土壤中的土壤微型食物网有负面影响，而在有微塑料污染的土壤中却增加了土壤微型食物网的复杂性和稳定性。干旱增加了可生物降解微塑料土壤中细菌和真菌之间负相关的比例，同时降低了小尺寸微塑料土壤中原生生物和线虫之间负相关的比例。我们的研究表明，干旱可能通过减少可生物降解微塑料污染土壤中较低营养级之间的竞争，以及减少小尺寸微塑料污染土壤中较高营养级之间的竞争，来减轻微塑料对土壤微型食物网的负面影响。
