Institute of Biology , Freie Universität Berlin . 14195 Berlin , Germany.
Leibniz-Institute of Freshwater Ecology and Inland Fisheries . 12587 Berlin , Germany.
Environ Sci Technol. 2019 May 21;53(10):6044-6052. doi: 10.1021/acs.est.9b01339. Epub 2019 May 7.
Microplastics can affect biophysical properties of the soil. However, little is known about the cascade of events in fundamental levels of terrestrial ecosystems, i.e., starting with the changes in soil abiotic properties and propagating across the various components of soil-plant interactions, including soil microbial communities and plant traits. We investigated here the effects of six different microplastics (polyester fibers, polyamide beads, and four fragment types: polyethylene, polyester terephthalate, polypropylene, and polystyrene) on a broad suite of proxies for soil health and performance of spring onion ( Allium fistulosum). Significant changes were observed in plant biomass, tissue elemental composition, root traits, and soil microbial activities. These plant and soil responses to microplastic exposure were used to propose a causal model for the mechanism of the effects. Impacts were dependent on particle type, i.e., microplastics with a shape similar to other natural soil particles elicited smaller differences from control. Changes in soil structure and water dynamics may explain the observed results in which polyester fibers and polyamide beads triggered the most pronounced impacts on plant traits and function. The findings reported here imply that the pervasive microplastic contamination in soil may have consequences for plant performance and thus for agroecosystems and terrestrial biodiversity.
微塑料会影响土壤的生物物理特性。然而，我们对于陆地生态系统基本层面上的事件级联过程（即从土壤非生物特性的变化开始，一直传播到包括土壤微生物群落和植物特性在内的土壤-植物相互作用的各个组成部分）知之甚少。在这里，我们研究了六种不同的微塑料（聚酯纤维、聚酰胺珠和四种碎片类型：聚乙烯、聚对苯二甲酸乙二醇酯、聚丙烯和聚苯乙烯）对大葱（ Allium fistulosum）土壤健康和性能的广泛指标的影响。观察到植物生物量、组织元素组成、根系特性和土壤微生物活性的显著变化。这些植物和土壤对微塑料暴露的反应被用来提出一种用于解释作用机制的因果模型。影响取决于颗粒类型，即与其他天然土壤颗粒形状相似的微塑料引起的与对照相比的差异较小。土壤结构和水动力的变化可以解释观察到的结果，其中聚酯纤维和聚酰胺珠对植物特性和功能产生了最显著的影响。这里报道的发现表明，土壤中普遍存在的微塑料污染可能会对植物的性能产生影响，从而影响农业生态系统和陆地生物多样性。
