Microplastics (MPs) as emerging contaminants have a global occurrence, including both terrestrial and marine ecosystems. Soil enzymes contribute to maintaining ecosystem multifunctionality, for example, nutrient cycling, organic material decomposition, and carbon and climate regulation. Our present review highlights the impacts of MPs on soil enzyme activities, influencing factors, and the underlying mechanisms. Increasing findings confirm that MPs can change the activities of a range of soil enzymes involved in the biogeochemical cycling of C and N. However, current results are highly controversial. The effects of MPs highly vary from significant to nonsignificant and are dependent on polymer type, biodegradability, dosage, size, shape, and aging degree of MPs, and exposure conditions. Compared to traditional MPs, biodegradable MPs generally show more pronounced effects. MPs can change soil enzyme activities via different pathways. On one hand, MPs can directly change soil enzyme structure, leading to alterations in enzyme activity. On the other hand, MPs can create unique habitats, provide carbon sources for specific functional microbes producing enzymes, and release plastic additives and pollutants disturbing the production of these enzymes. Furthermore, MPs can alter soil physicochemical and biological properties, the availability of substrates, plants and soil fauna, regulating soil enzymes and their functions. In conclusion, MPs can regulate soil enzyme activities and pose a profound impact on ecosystem multifunctionality.

中文翻译：

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微塑料影响生态系统的多功能性：来自土壤酶活性的越来越多的证据


微塑料（MP）作为新兴污染物在全球范围内普遍存在，包括陆地和海洋生态系统。土壤酶有助于维持生态系统的多功能性，例如养分循环、有机物质分解以及碳和气候调节。我们目前的综述重点介绍了 MP 对土壤酶活性的影响、影响因素和潜在机制。越来越多的研究结果证实，MP 可以改变一系列参与碳和氮生物地球化学循环的土壤酶的活性。然而，目前的结果存在很大争议。 MP 的影响从显着到不显着都有很大差异，并且取决于聚合物类型、生物降解性、剂量、MP 的大小、形状和老化程度以及暴露条件。与传统MP相比，可生物降解MP通常表现出更明显的效果。 MP 可以通过不同的途径改变土壤酶的活性。一方面，MPs可以直接改变土壤酶的结构，导致酶活性的改变。另一方面，MP可以创造独特的栖息地，为产生酶的特定功能微生物提供碳源，并释放干扰这些酶产生的塑料添加剂和污染物。此外，MP 可以改变土壤理化和生物特性、基质、植物和土壤动物的可用性，调节土壤酶及其功能。总之，MPs可以调节土壤酶活性并对生态系统多功能性产生深远影响。