Freie Universität Berlin, Institute of Biology, Plant Ecology, Berlin, Germany.
Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany.
Environ Microbiol. 2024 Feb;26(2):e16549. doi: 10.1111/1462-2920.16549. Epub 2024 Jan 10.
Microplastics affect soil functions depending on drought conditions. However, how their combined effect influences soil fungi and their linkages with ecosystem functions is still unknown. To address this, we used rhizosphere soil from a previous experiment in which we employed microplastic fibres addition and drought in a factorial design, and evaluated their effects on soil fungal communities. Microplastics decreased soil fungal richness under well-watered conditions, likely linked to microplastics leaching toxic substances into the soil, and microplastic effects on root fineness. Under drought, by contrast, microplastics increased pathogen and total fungal richness, likely related to microplastic positive effects on soil properties, such as water holding capacity, porosity or aggregation. Soil fungal richness was the attribute most affected by microplastics and drought. Microplastics altered the relationships between soil fungi and ecosystem functions to the point that many of them flipped from positive to negative or disappeared. The combined effect of microplastics and drought on fungal richness mitigated their individual negative effect (antagonism), suggesting that changes in soil water conditions may alter the action mode of microplastics in soil. Microplastic leaching of harmful substances can be mitigated under drought, while the improvement of soil properties by microplastics may alleviate such drought conditions.
微塑料会根据干旱条件影响土壤功能。然而，它们的综合影响如何影响土壤真菌及其与生态系统功能的联系仍然未知。为了解决这个问题，我们使用了先前实验中的根际土壤，在该实验中，我们采用了微塑料纤维添加和干旱的因子设计，并评估了它们对土壤真菌群落的影响。在水分充足的条件下，微塑料减少了土壤真菌的丰富度，这可能与微塑料将有毒物质浸出到土壤中以及微塑料对根细度的影响有关。相比之下，在干旱条件下，微塑料增加了病原菌和总真菌的丰富度，这可能与微塑料对土壤性质（如持水能力、孔隙度或团聚体）的积极影响有关。土壤真菌丰富度是受微塑料和干旱影响最大的属性。微塑料改变了土壤真菌与生态系统功能之间的关系，以至于许多关系从正相关变为负相关或消失。微塑料和干旱对真菌丰富度的综合影响减轻了它们各自的负面影响（拮抗作用），这表明土壤水分条件的变化可能改变了微塑料在土壤中的作用模式。微塑料浸出有害物质的情况在干旱条件下可能会得到缓解，而微塑料改善土壤性质的情况可能会缓解干旱条件。
