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

题为《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进行量化、建模和管理的需要，这是人们非常感兴趣的主题。土壤水分是微生物异养活性的关键决定因素，因此是连接陆地生境中水循环和碳循环的最重要的参数。有必要将对土壤水分过程的物理理解与深入研究其在多个营养水平对微生物群落的影响结合起来。本工作的研究假设是，微生物对干湿循环的响应在不同的微生物类群中是不同的，主要是由于两个因素：1)对干燥的生理反应不同，2)土壤基质中不同的位置导致不同的干燥压力暴露。这个项目考虑的两个营养级别是细菌和活泼的原生动物。这项研究将把土壤微生物群落结构的动态量化为土壤水分的时间依赖函数，然后针对特定的类群显示出明显的变化。后续工作将研究哪种因素在决定特定微生物分类群的干燥反应方面影响最大。该项目包括本科生，为他们提供了获得微生物生态学和土壤水文学方面的研究技能的机会，使他们成为环境领域或工业领域研究生水平学习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.