The Research Initiation Award entitled - Response of Microbial Communities to Short-Timescale In-situ Soil Moisture Dynamics - seeks to understand the role of microbial communities in the global carbon cycle, which is the subject of much interest in light of current needs to quantify, model and manage carbon inputs to the atmosphere. Soil water content is a critical determinant of microbial heterotrophic activity and is therefore the single most important parameter linking the water cycle and the carbon cycle in terrestrial habitats. There is a need to integrate a physically-based understanding of soil water processes with an in-depth study of their effects on the microbial community at multiple trophic levels.
The research hypothesis of this work is that microbial responses to wetting/drying cycles vary among microbial taxa primarily as a result of two factors: 1) differences in physiological responses to desiccation, and 2) varying locations within the soil matrix resulting in differential exposure to desiccation stresses. The two trophic levels under consideration in this project are bacteria and bactivorous protozoa. The study will quantify the dynamics of soil microbial community structure as a time-dependent function of soil moisture, then target specific taxa showing appreciable changes. Follow-on work will examine which factor is most influential in determining the desiccation response for specific microbial taxa. The project includes undergraduate students by providing them with an opportunity to gain research skills in both microbial ecology and soil hydrology, making them attractive candidates for graduate-level study in the environmental field or in industry.
