College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
Sci Total Environ. 2022 Mar 15;812:151487. doi: 10.1016/j.scitotenv.2021.151487. Epub 2021 Nov 4.
The effect of microplastics on soil ecosystem is a hot topic in recent years. It is increasingly recognized that soil is also an important sink for microplastics in addition to the aquatic environment. This review aims to discuss the direct and indirect effects of microplastics on the soil-plant system, focusing on the effects of microplastics on soil aggregates and soil nutrient cycling as well as the combined effects of microplastics and other pollutants on soil-plant systems. Microplastics have been shown to affect the rooting ability of plants by altering soil bulk density and water-holding capacity, as well as reducing photosynthetic rate by directly interfering with the balance of plant chlorophyll a/chlorophyll b ratios. In addition, microplastics affect the stability of aggregates by interfering with abiotic factors (e.g., sesquioxide and exchangeable cations) or biotic factors (e.g., soil organic matter and organism activities in the soil). Moreover, microplastics may affect soil nutrient cycling by altering the dominant bacteria phyla in the soil or genes and enzymes associated with the carbon, nitrogen, and phosphorus cycle. When microplastics and other pollutants have combined effects on plants, microplastics attached onto the root surface physically hamper the contact of the pollutants with the roots but are more likely to exacerbate the damage of pollutants to plants. Different types, sizes and concentrations of microplastics have different effects on the soil-plant system. Microplastics with similar shape and size to soil particles have less significant effects, while microfibers, small-sized microplastics and biodegradable plastic particles have more significant effects. Finally, this review also provides an outlook for future research.
微塑料对土壤生态系统的影响是近年来的一个热点话题。人们越来越认识到，土壤除了是水生环境中微塑料的重要汇，也是微塑料的重要汇。本综述旨在讨论微塑料对土壤-植物系统的直接和间接影响，重点讨论微塑料对土壤团聚体和土壤养分循环的影响，以及微塑料和其他污染物对土壤-植物系统的联合影响。研究表明，微塑料通过改变土壤容重和持水能力，以及通过直接干扰植物叶绿素 a/叶绿素 b 比值的平衡来降低光合速率，从而影响植物的生根能力。此外，微塑料通过干扰非生物因素（如二氧化硅和可交换阳离子）或生物因素（如土壤有机质和土壤中的生物活动）来影响团聚体的稳定性。此外，微塑料可能通过改变土壤中优势细菌门或与碳、氮和磷循环相关的基因和酶来影响土壤养分循环。当微塑料和其他污染物对植物产生联合效应时，附着在根表面的微塑料会物理上阻碍污染物与根的接触，但更有可能加剧污染物对植物的损害。不同类型、大小和浓度的微塑料对土壤-植物系统的影响不同。与土壤颗粒形状和大小相似的微塑料的影响较小，而微纤维、小尺寸微塑料和可生物降解塑料颗粒的影响较大。最后，本综述还展望了未来的研究方向。
