Liu Yan, Wang Wenfeng, He Jianzhou
College of Geographic Sciences, Changchun Normal University, Changchun 130032, China.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China.
Sci Total Environ. 2024 Dec 1;954:176658. doi: 10.1016/j.scitotenv.2024.176658. Epub 2024 Oct 4.
Soil is the largest environmental reservoir of microplastics (MPs) on the earth. Incremental accumulation of MPs in the soil can cause significant changes in soil physicochemical and microbial traits, which may in turn interfere with soil biogeochemical processes such as carbon cycling. With published research regarding MPs impacts on soil carbon cycling growing rapidly, a systematic review summarizing the current knowledge and highlighting future research needs is warranted. As carbon-rich polymers, MPs can contribute to soil organic carbon (SOC) storage via degradation and leaching. MPs can also affect the humification of dissolved organic matters (DOM), consequently influencing the stability of SOC. Exposure to MPs can cause substantial impacts on the growth performance, litter decomposition, and root secretion of terrestrial plants as well as soil microbial carbon turnover, inducing changes in the formation of SOC. The presence of MPs has contrasting effects on the emissions of both CO and CH from the soil. The diverse effects of MPs on soil carbon metabolism could be partly attributed to the varying changes in soil microbial community structure, functional gene expression, and enzyme activity under MPs exposure. Further research is still highly needed to clarify the pathways of MPs impacts on soil carbon cycling and the driving biological and physicochemical factors behind these processes.
土壤是地球上最大的微塑料环境储存库。微塑料在土壤中的累积会导致土壤物理化学和微生物特性发生显著变化，进而可能干扰土壤生物地球化学过程，如碳循环。随着关于微塑料对土壤碳循环影响的已发表研究迅速增加，有必要进行一项系统综述，总结当前知识并突出未来研究需求。作为富含碳的聚合物，微塑料可通过降解和淋溶促进土壤有机碳（SOC）储存。微塑料还会影响溶解有机物（DOM）的腐殖化，从而影响土壤有机碳的稳定性。接触微塑料会对陆生植物的生长性能、凋落物分解和根系分泌以及土壤微生物碳周转产生重大影响，进而导致土壤有机碳形成的变化。微塑料的存在对土壤中一氧化碳和甲烷的排放有相反的影响。微塑料对土壤碳代谢的多种影响可能部分归因于微塑料暴露下土壤微生物群落结构、功能基因表达和酶活性的不同变化。仍迫切需要进一步研究来阐明微塑料影响土壤碳循环的途径以及这些过程背后驱动的生物和物理化学因素。
