Metagenomic Insights into the Impact of Prescribed Fire on the Soil Microbiome of Satpura Tiger Reserve, Central India

Abstract Fires can irreversibly alter soil structure and chemistry thereby disrupting nutrient cycles. Soil microbial indicators are thus crucial for assessing the ecological impact of such disturbances. This study investigates the short-term effects of prescribed vegetation burning on soil bacterial and fungal communities in a tropical forest. Clay-rich vertisolic soil samples from fire-treated and untreated sites were collected and subjected to next-generation DNA sequencing, to estimate the soil microbial diversity and composition. We targeted bacterial 16S rRNA genes and fungal ITS regions to identify the microbial taxa. Alpha diversity metrics (Chao1, Shannon, and Simpson indices) revealed slight variations between treatments, with untreated sites displaying marginally higher bacterial and fungal diversity. PERMANOVA analysis indicated a higher pseudo-F value for bacterial communities (32.429) versus fungi (0.741) suggesting that bacterial communities may be more responsive to fire than fungal communities. However, the effects of prescribed fire on both bacterial and fungal composition and diversity were found to be statistically non-significant (P > 0.05). While fungal communities demonstrated resilience, possibly due to mycorrhizal associations, bacterial communities showed relatively greater compositional shifts, aligning with prior studies on microbial sensitivity to environmental changes. These findings suggest that controlled vegetation burning does not significantly disrupt microbial diversity or composition in tropical forest soils. The findings contribute to refining prescribed fire practices aimed at sustaining soil microbial integrity and maintaining soil health in tropical forest ecosystems.