HBCU-UP Research Initiation Award Grant: Response of Microbial Communities to Short-Timescale In-situ Soil Moisture Dynamics

这项名为“微生物群落对短时间尺度原位土壤水分动态的响应”的研究启动奖旨在了解微生物群落在全球碳循环中的作用，鉴于目前对大气碳输入的量化、建模和管理需求，这是一个非常感兴趣的主题。土壤含水量是微生物异养活动的关键决定因素，因此是连接陆地栖息地水循环和碳循环的最重要参数。有必要将基于物理的土壤水分过程的理解与深入研究它们在多个营养水平上对微生物群落的影响结合起来。本研究的研究假设是，微生物对干湿循环的反应在不同的微生物分类群中存在差异，主要是由于两个因素：1)对干燥的生理反应的差异；2)土壤基质中不同的位置导致对干燥胁迫的不同暴露。本项目考虑的两个营养水平是细菌和双食性原生动物。研究将土壤微生物群落结构的动态量化为土壤湿度的时间依赖函数，然后针对特定的类群表现出明显的变化。后续工作将研究哪个因素在确定特定微生物分类群的干燥反应中最具影响力。该项目包括本科生，为他们提供获得微生物生态学和土壤水文学研究技能的机会，使他们成为环境领域或工业领域研究生水平研究的有吸引力的候选人。

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.