Effect drying cycles on bacterial growth in soil

Drying and rewetting is a frequent physiological stress for soil microbial communities. The strong influence of drying-rewetting events on microbially mediated processes in soil, including C and N mineralization, are well known. Thus far, we have been largely limited to a black-box understanding of these processes, and the ecological mechanisms underlying them have remained elusive. Studies on drying-rewetting effects on the soil microbial community to date have almost exclusively used biomass-based approaches. We investigated the effect of repeated drying-rewetting cycles on biomass concentration and respiration. We found that repeated drying-rewetting cycles severely decreased bacterial growth. Additionally, a clear difference in the effect on growth rates from both respiration-based and biomass-based assessments of the bacterial community in the same study underscores that bacterial responses to perturbations might previously have been underrated. In light of this, many aspects of environmental microbial ecology may need to be revisited with a close attention to what measure of the microbial community is relevant to study.

کلیدواژه ها:

drying-rewetting ، bacterial growth ، respiration ، biomass