Short-Term Pesticide Exposure Reshapes Soil Fungal Communities in a Soil-Dependent Manner

Soil fungi play key roles in decomposition, nutrient cycling, plant–soil interactions, and soil structure, yet their immediate responses to pesticides remain insufficiently understood. Most studies have focused on long-term, cumulative, or plant-mediated effects, limiting insight into direct impacts. We assessed the short-term direct effects of eight commercial pesticides on fungal abundance, alpha diversity, community composition, trophic structure, and total arbuscular mycorrhizal fungal (AMF) abundance across three contrasting agricultural soils in a plant-free pot experiment. Responses varied strongly among soils and pesticides, with no consistent fungal suppression. Alpha-diversity changed little and inconsistently, whereas community composition shifted markedly, indicating rapid community reorganization before detectable changes in richness or evenness. Soil 1 showed the strongest responses, while Soil 2 was resistant. Although most trophic groups’ relative abundance remained stable, their internal composition was often substantially restructured, suggesting taxonomic turnover without major functional-group shifts. Total AMF abundance increased under several treatments in Soil 1 but decreased under selected treatments in Soil 3. Soil pH was associated with fungal diversity, community composition, and total AMF abundance; however, pesticide-induced pH changes did not consistently explain microbial responses. Overall, short-term pesticide exposure drove selective, soil-dependent community restructuring rather than uniform diversity loss, supporting soil-specific risk assessment.