Biochar alters the resistance and resilience to drought in a tropical soil

Soil microbes play a key role in nutrient cycling and carbon sequestration. Global change can alter soil microbial population composition and behavior. Biochar addition has been explored in the last years as a way to mitigate global warming. However, responses of microbial communities to biochar addition in particular in relation to abiotic disturbances are seldom documented. An example of these disturbances, which is predicted to be exacerbated with global warming, is regional drought. It has been known that fungal-based food webs are more resistant to drought than their bacterial counterparts. Our study found that biochar addition can increase the resistance of both the bacterial and fungal networks to drought. Contrary to expected, this result was not related to a change in the dominance of fungal or bacteria. In general, soil amended with biochar was characterized by a faster recovery of soil microbial properties to its basal values. Biochar addition to the soil also suppressed the Birch effect, a result that has not been previously reported.