Collaborative Research: Biogeochemistry of Cyanobacterial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley glacial metlwater streams

合作研究：麦克默多干谷冰川融水流中蓝藻垫和潜流区微生物的生物地球化学

• 批准号: 0739640
• 负责人: Edward Carpenter
• 金额: $ 40万
• 依托单位: San Francisco State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0739640&HistoricalAwards=false
• 关键词: Collaborative; Research; Biogeochemistry; Cyanobacterial; Mats

The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein & DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs.

McMurdo干山谷的冰川流具有广泛的蓝细菌垫，是山谷中固定C和N的可能来源。该研究将检查短暂冰川流中的微生物垫与降低土壤（湿土壤区）的微生物群中的微生物垫之间的相互作用，并与这些垫子相邻。据推测，垫子是低孔区的土壤群落的有机碳和固定氮的重要来源，并释放了为整个干谷生态系统服务的溶解有机碳（DOC）和氮（DON）。现场努力将需要观察和实验组成部分。将进行直接比较自然再生和干燥的垫子区域的垫子和微生物种群，以及在米尔斯山谷的亚当斯和米尔斯冰川熔体流中的垫子区域之间。将检查土壤菌群的生理和系统发育指数。观察结果将包括通过土壤细菌，细菌密度及其分子生态学的估计MAT碳和氮固定率，土壤呼吸以及亮氨酸的摄取（分别为蛋白质和DNA合成的量度）。实验性操作将包括对土壤的实验重新润湿以及对微生物群落反应时间过程的观察。 这项研究将将现代分子遗传学方法（ARISA-DNA指纹和超深16S RDNA微生物系统发育分析）与地球化学相结合，以研究在这些极端环境中繁荣发展的微生物群落的多样性，生态和功能。 该项目的更广泛影响包括研究生和博士后同学的研究和教育机会。 P.I.S将涉及大学生和REU课程的本科生，并将参加教育和外展计划。