Responses of soil microbial communities to prescribed burning in two paired vegetation sites in southern China

Prescribed burning is a common site preparation practice for forest plantation in southern China. However, the effects of prescribed burning on soil microbial communities are poorly understood. This study examined changes in microbial community structure, measured by phospholipid fatty acids (PLFAs), after a single prescribed burning in two paired vegetation sites in southern China. The results showed that the total amount of PLFA (totPLFA) was similar under two vegetation types in the wet season but differed among vegetation type in the dry season, and was affected significantly by burning treatment only in the wet season. Bacterial PLFA (bactPLFA) and fungal PLFA (fungPLFA) in burned plots all decreased compared to the unburned plots in both seasons (P = 0.059). Fungi appeared more sensitive to prescribed burning than bacteria. Both G(+) bacterial PLFA and G(-) bacterial PLFA were decreased by the burning treatment in both dry and wet seasons. Principal component analysis of PLFAs showed that the burning treatment induced a shift in soil microbial community structure. The variation in soil microbial community structure was correlated significantly to soil organic carbon, total nitrogen, available phosphorus and exchangeable potassium. Our results suggest that prescribed burning results in short-term changes in soil microbial communities but the long-term effects of prescribed burning on soil microbial community remain unknown and merit further investigation.