Effects of varying CO2 flows on bacterial communities in mesocosms created from two soils

Abstract Although leakages from carbon capture and storage sites are not expected, it is necessary to be prepared for that possibility and evaluate its risk on soil bacterial communities. Since most studies regarding CO 2 effects have been performed in natural sites, the current study was conducted in an experimental site (PISCO2, Spain) in an attempt to consider the short term instead of the long-term effects on bacterial communities, together with the effects of low CO 2 below-ground emissions. High-throughput sequencing of 16S RNA genes was used to evaluate the composition and structure of two soils bacterial communities. Overall, communities presented different compositions and structures between soils. The analysis of communities sampled in each soil showed partial shifts in bacterial community composition, but no consistent effects on the richness and diversity. CO 2 flux effects on community composition were mainly observed in one soil type, in which the CO 2 flux could be considered as one of the factors that contributes to shape bacterial communities, even at low CO 2 fluxes and short term emissions.