Dissertation Research: Microbial Responses to Variation in Dissolved Organic Carbon (DOC) Quality and Quantity in the Hyporheic Zone of Stream Ecosystems

论文研究：微生物对溪流生态系统潜流区溶解有机碳 (DOC) 质量和数量变化的反应

• 批准号: 9411844
• 负责人: Robert Howarth
• 金额: $ 1万
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9411844&HistoricalAwards=false
• 关键词: Dissertation; Research; Microbial; Responses; Variation

9411844 Howarth The dimensions of stream ecosystem studies have been greatly expanded within the last decade to include saturated sediments that lie beneath and adjacent to the streambed. Recent work indicates the hyporheic zone's importance in regulating stream metabolism, altering stream chemistry, and supporting stream food webs. Although the hyporheic zone contains diverse microbial and invertebrate communities, benthic bacteria are at the base of the hyporheic food web and thought to control much of its ecosystem function. The primary energy source for benthic bacteria is dissolved organic carbon (DOC). This dissertation research will determine the extent to which variation in DOC quality and quantity affects the microbial community in stream hyporheic zones. Research will address how DOC from contrasting sources within and among streams that are thought to vary in DOC quality and quantity affect the bacterial community in the hyporheic zone. Changes in bacterial abundance and productivity in response to changes in DOC, as well as subsequent changes in water chemistry will be studied. This research will also determine if hyporheic microbes serve as a carbon sink or an important link to higher trophic levels in stream food webs. %%% The objectives of this research will lead to a greater understanding of both stream ecosystem function and microbial loop dynamics. This study will provide an excellent forum to link ecosystem-level function with previously poorly understood microbial processes.

9411844 Howarth 河流生态系统研究的范围在过去十年中已大大扩展，包括位于河床下方和附近的饱和沉积物。最近的研究表明，潜流带在调节河流新陈代谢、改变河流化学和支持河流食物网方面具有重要意义。尽管潜流带包含多种微生物和无脊椎动物群落，但底栖细菌位于潜流食物网的基础，被认为控制着其大部分生态系统功能。底栖细菌的主要能源是溶解有机碳（DOC）。本论文研究将确定 DOC 质量和数量的变化对溪流潜流区微生物群落的影响程度。研究将解决来自溪流内部和溪流之间不同来源的 DOC 如何影响潜流区细菌群落的问题，这些溪流的 DOC 质量和数量各不相同。将研究细菌丰度和生产力随 DOC 变化而变化，以及水化学的后续变化。这项研究还将确定潜流微生物是否充当碳汇或与溪流食物网中更高营养水平的重要联系。 %%% 这项研究的目标是加深对河流生态系统功能和微生物循环动力学的了解。这项研究将提供一个很好的论坛，将生态系统层面的功能与以前知之甚少的微生物过程联系起来。