Vanadium (V) and microplastics in soils draw increasing attention considering their significant threats to ecosystems. However, little is known about the vertical co-distribution of V and microplastics in soil profile and their combined effects on microbial community dynamics and assembly. This study investigated the spatial distribution of V and microplastics in the soils at a V smelting site and the associated microbial community characteristics along the vertical gradient. Both V and microplastics were found in the 50 cm soil profile with average concentrations of 203.5 ± 314.4 mg/kg and 165.1 ± 124.8 item/kg, respectively. Topsoil (0–20 cm) and subsoil (20–50 cm) displayed distinct microbial community compositions. Metal-tolerant (e.g., Spirochaeta, Rubellimicrobium) and organic-degrading (e.g., Bradyrhizobium, Pseudolabrys) taxa as biomarkers were more abundant in the topsoil layer. V and microplastics directly affected the microbial structure in the topsoil and had indirect influences in the subsoil, with direct impacts from organic matter. In topsoil, deterministic processes were more prevalent for community assembly, whereas stochastic processes governed the subsoil. The interspecific relationship was closer in topsoil with greater network complexity and higher modularity. These findings promote the understanding of distinct heterogeneity of microbial communities jointly driven by V and microplastics in soil environment.

考虑到它们对生态系统的重大威胁，土壤中的钒 (V) 和微塑料引起了越来越多的关注。然而，关于 V 和微塑料在土壤剖面中的垂直共分布及其对微生物群落动力学和组装的综合影响知之甚少。本研究调查了 V 冶炼厂土壤中 V 和微塑料的空间分布以及沿垂直梯度的相关微生物群落特征。在 50 cm 土壤剖面中发现了 V 和微塑料，平均浓度分别为 203.5 ± 314.4 mg/kg 和 165.1 ± 124.8 item/kg。表土（0-20 厘米）和底土（20-50 厘米）显示出不同的微生物群落组成。金属耐受性（如螺旋体、风疹菌属）和有机降解性（如慢生根瘤菌、Pseudolabrys) 分类群作为生物标志物在表土层中更为丰富。V 和微塑料直接影响表层土壤中的微生物结构，间接影响下层土壤中的有机质。在表土中，确定性过程在群落组装中更为普遍，而随机过程则支配着底土。表层土壤的种间关系更密切，网络复杂度更高，模块化程度更高。这些发现促进了对土壤环境中由 V 和微塑料共同驱动的微生物群落的不同异质性的理解。确定性过程在群落组装中更为普遍，而随机过程则支配着底土。表层土壤的种间关系更密切，网络复杂度更高，模块化程度更高。这些发现促进了对土壤环境中由 V 和微塑料共同驱动的微生物群落的不同异质性的理解。确定性过程在群落组装中更为普遍，而随机过程则支配着底土。表层土壤的种间关系更密切，网络复杂度更高，模块化程度更高。这些发现促进了对土壤环境中由 V 和微塑料共同驱动的微生物群落的不同异质性的理解。