Response of Soil Fungal Diversity and Community Composition to Varying Levels of Bamboo Biochar in Red Soils

Soil fungi play a vital role in soil nutrient dynamics, but knowledge of their diversity and community composition in response to biochar addition into red soil is either limited or inconsistent. Therefore, we determined the impact of bamboo biochar (BB) with increasing concentrations (0, 5, 20, and 80 g kg(−1) of soil, referred to as B0, BB5, BB20, and BB80, respectively) on soil physicochemical properties and fungal communities (Illumina high-throughput sequencing) in red soil under Fokenia hodginsii (Fujian cypress). We found that increasing BB levels effectively raised the soil pH and soil nutrients, particularly under BB80. BB addition significantly increased the relative abundance of important genera, i.e., Basidiomycota, Mucoromycota, and Chytridiomycota that could play a key role in ecological functioning, e.g., wood degradation and litter decomposition, improvement in plant nutrients uptake, and resistance to several abiotic stress factors. Soil amended with BB exhibited a substantial ability to increase the fungal richness and diversity; BB80 > BB20 > BB5 > B0. Basidiomycota, Mucoromycota, Glomeromycota, Rozellomycota, Aphelidiomycota, Kickxellomycota, and Planctomycetes were positively associated with soil pH, total nitrogen, phosphorous, and carbon, and available potassium and phosphorous. Besides, the correlation analysis between the soil fungal communities and soil properties also showed that soil pH was the most influential factor in shaping the soil fungal communities in the red soil. These findings have significant implications for a comprehensive understanding of how to ameliorate acidic soils with BB addition, as well as for future research on sustainable forest management, which might increase soil fungi richness, diversity, and functionality in acidic soils.