How do rainfall patterns change microbial induced carbon dynamics in soil?

English. Climate change is changing the precipitation patterns around the globe, leading to more extreme weather events like severe drought and heavy rainfalls. These events are intrinsically related to soil moisture fluctuations, which strongly modulates carbon fluxes in terrestrial ecosystems. Studying the behavior of microbial communities present in agriculture soils during drying and rewetting events can help understand soil dynamics under climate change scenarios and help the knowledge gap of how perennial crops can be useful in reducing climate change consequences. In this project, I compared perennial and annual crop systems in depth, down to 90 cm, by characterizing the soils and measuring their microbial responses to a drying and rewetting event. From this study, it was possible to conclude that both soils present a sensitive response to such event, with both lag and recovery times increasing with depth. Moreover, soils exposed to perennial crops generally showed shorter lag and recovery times than those from annual crops, which suggests that perennial crops might have a higher capacity to withstand the negative effects of droughts. Based on the results obtained and the intrinsic limitations of the experiment, it is clear that further investigation is needed, namely in the form of respiration studies, more replicates and statistical analysis.

English. Climate change is causing extreme weather events worldwide, like severe droughts and heavy rainfall, by changing precipitation patterns. These events affect water levels and have a major impact on carbon movement in soils. To understand how soil behaves under changing climate conditions, I studied how microbes in agricultural soils behave after drying and rewetting events, by comparing perennial and annual crops soils to explore their potential in mitigating climate change effects. I characterized soils from perennial and annual croplands from Skåne, Sweden and conducted drying and rewetting experiments to evaluate the microbial responses. The results showed that both soil types were sensitive to drought, with microbes taking longer to recover in deeper soils. Surprisingly, soils from perennial crops showed to be better adapted to drought conditions, with the potential to help fight climate change. Future studies should include more replicates, analyze respiration and the microbial communities by sequencing DNA, and apply statistical techniques to support the validity of the conclusions.