Impact of Coexistence of Microplastics and Biochar on the Abundance and Structure of Soil Fungal Communities

In this pursuit, we analyzed the effects of microplastics (PP, PE, PVC) and microplastics and biochar coexistence (PPR, PER, PVCR) on soil fungal community structure and diversity, and functional prediction analysis. Results showed that microplastics and their coexistence with biochar had a significant impact on the soil physicochemical, with PVCR treatment exhibiting the highest soil pH, organic carbon, phosphorus, potassium, and ammonium nitrogen content. Microplastics and their coexistence with biochar significantly increased fungal abundance, with PPR treatment having the highest fungal abundance. Microplastics and their coexistence with biochar (except for PP) significantly reduced the soil fungal diversity indices. The dominant fungal communities were Ascomycota, Basidiomycota, and Zygomycota, while at the genus level, Mortierella, Aspergillus, and Fusarium were found to be dominant taxa. Microplastics and their coexistence with biochar promoted the Basidiomycota and Mortierella and inhibited the Ascomycota and Fusarium. Effect of microplastics and biochar coexistence was significantly higher than that of microplastics alone. Soil pH, ammonium nitrogen, organic carbon, nitrate nitrogen, and potassium were main factors affecting the soil fungal community structure changes. FUNGuild functional prediction results showed that microplastics and their coexistence with biochar had a significant influence on the functional group. The relative abundance of pathogenic-saprotrophic-symbiotic nutritional fungi was the highest in the PPR while the PVCR showed the highest relative abundance of saprotrophic nutritional fungi. In summary, the coexistence of microplastics and biochar had a significant affect the soil fungal community, while its impact exhibited variations depending on the type of microplastics.