College of Forestry, Shandong Agricultural University, Taian 271018, China.
College of Resources and Environment, Shandong Agricultural University, Key Laboratory of Agricultural Environment in Universities of Shandong, Taian 271018, China.
Sci Total Environ. 2024 Mar 10;915:170094. doi: 10.1016/j.scitotenv.2024.170094. Epub 2024 Jan 13.
Microplastics derived from polyethylene (PE) mulch films are widely found in farmland soils and present considerable potential threats to agricultural soil ecosystems. However, the influence of microplastics derived from PE mulch films, especially those derived from farmland residual PE mulch films, on soil ecosystems remains unclear. In this study, we analyzed the bacterial communities attached to farmland residual transparent PE mulch film (FRMF) collected from peanut fields and the different ecological effects of unused PE mulch film-derived microplastics (MPs) and FRMF-derived microplastics (MPs-aged) on the soil and earthworm Metaphire guillelmi gut microbiota, functional traits, and co-occurrence patterns. The results showed that the assembly and functional patterns of the bacterial communities attached to the FRMF were clearly distinct from those in the surrounding farmland soil, and the FRMF enriched some potential plastic-degrading and pathogenic bacteria, such as Nocardioidaceae, Clostridiaceae, Micrococcaceae, and Mycobacteriaceae. MPs substantially influenced the assembly and functional traits of soil bacterial communities; however, they only significantly changed the functional traits of earthworm gut bacterial communities. MPs-aged considerably affected the assembly and functional traits of both soil and earthworm gut bacterial communities. Notably, MPs had a more remarkable effect on nitrogen-related functions than the MPs-aged in numbers for both soil and earthworm gut samples. Co-occurrence network analysis revealed that both MPs and MPs-aged enhanced the synergistic interactions among operational taxonomic units (OTUs) of the composition networks for all samples. For community functional networks, MPs and MPs-aged enhanced the antagonistic interactions for soil samples; however, they exhibited contrasting effects for earthworm gut samples, as MPs enhanced the synergistic interactions among the functional contents. These findings broaden and deepen our understanding of the effects of FRMF-derived microplastics on soil ecosystems, suggesting that the harmful effects of aged plastics on the ecological environment should be considered.
农田土壤中广泛存在源于聚乙烯（PE）地膜的微塑料，对农业土壤生态系统存在较大的潜在威胁。然而，源于 PE 地膜的微塑料，尤其是源于农田残留 PE 地膜的微塑料，对土壤生态系统的影响尚不清楚。本研究分析了从花生地采集的农田残留透明 PE 地膜（FRMF）上附着的细菌群落，以及未使用的 PE 地膜衍生微塑料（MPs）和 FRMF 衍生微塑料（MPs-aged）对土壤和赤子爱胜蚓肠道微生物群落、功能特征和共生模式的不同生态影响。结果表明，FRMF 上附着细菌群落的组装和功能模式明显不同于周围农田土壤，FRMF 富集了一些潜在的塑料降解和致病细菌，如诺卡氏菌科、梭菌科、微球菌科和分枝杆菌科。MPs 显著影响土壤细菌群落的组装和功能特征；然而，它们仅显著改变了赤子爱胜蚓肠道细菌群落的功能特征。MPs-aged 对土壤和赤子爱胜蚓肠道细菌群落的组装和功能特征都有较大影响。值得注意的是，MPs 在数量上对土壤和赤子爱胜蚓肠道样本的氮相关功能的影响大于 MPs-aged。共生网络分析表明，MPs 和 MPs-aged 均增强了所有样本组成网络中分类单元（OTUs）的协同相互作用。对于群落功能网络，MPs 和 MPs-aged 增强了土壤样本的拮抗相互作用；然而，它们对赤子爱胜蚓肠道样本表现出相反的影响，因为 MPs 增强了功能含量之间的协同相互作用。这些发现拓宽并深化了我们对 FRMF 衍生微塑料对土壤生态系统影响的认识，表明老化塑料对生态环境的有害影响应该得到考虑。
