DISSERTATION RESEARCH: Energy Flow and Carbon Sources in a Montane Floodplain Aquifer

论文研究：山地洪泛区含水层中的能量流和碳源

• 批准号: 0508903
• 负责人: Richard Hauer
• 金额: $ 1万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0508903&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Energy; Flow; Carbon

At our study site on the Nyack floodplain of the Flathead River, Montana, large numbers of aquatic invertebrates, from microscopic copepods to large stoneflies and crustaceans, are found in groundwater pumped from wells distributed across the floodplain. Compared to the nearby river channel, which receives solar energy and food from algal production and terrestrial sources such as leaves, the groundwater must import food and nutrients from the river or through the floodplain soil. Our research has shown that food resources in the groundwater are very low. So, how can so many invertebrates live in an area with so little food? To address this question, we are developing a carbon budget for the groundwater system investigating the various organic matter sources; from river water, from overlying soils, or as buried plant matter as the river shifts its channel over time. This organic matter is consumed by microbes, which in turn feed the invertebrates. With funding from this proposal, we shall refine our understanding of the organic budget in two ways: through (1) respiration experiments, (consumption of oxygen to produce carbon dioxide by invertebrates and bacteria & fungi), and; (2) use of stable isotopes of carbon and nitrogen (that are unique to river vs. soil sources). The respiration experiments will let us calculate the energy used by various organisms and compare these to measurements from water samples taken from across the whole aquifer. In another experiment, using a constructed groundwater chamber, we will use respiration to tell us how strongly the organisms respond to carbon additions from soil or river water sources. Intellectual Merit: this proposal will significantly increase our understanding of the basic biology of organisms that live in river-connected river floodplain aquifers.Broader Impacts: In the west, mountain valleys and floodplains are where human population, agriculture, and drinking water overlap. By looking at a pristine aquifer, the research will tell us how groundwater systems work in ways important to understanding human impacts

在蒙大拿州平头河奈亚克洪泛区的研究现场，从微观桡足类动物到大型石蝇和甲壳类动物，大量水生无脊椎动物被发现存在于从分布在洪泛区的威尔斯井抽取的地下水中。与附近的河道相比，地下水必须从河流或河漫滩土壤中输入食物和营养物质，而河道从藻类生产和树叶等陆地来源获得太阳能和食物。我们的研究表明，地下水中的食物资源非常少。 那么，这么多的无脊椎动物怎么能生活在一个食物如此少的地区呢？为了解决这个问题，我们正在为地下水系统开发一个碳预算，调查各种有机物质的来源;从河水，从覆盖的土壤，或作为埋藏的植物物质，随着时间的推移，河流改变其通道。这些有机物被微生物消耗，而微生物又反过来喂养无脊椎动物。有了这项提案的资助，我们将通过两种方式来完善我们对有机预算的理解：（1）呼吸实验，（无脊椎动物和细菌真菌消耗氧气产生二氧化碳），以及;（2）使用碳和氮的稳定同位素（河流与土壤来源所特有的）。呼吸实验将让我们计算出各种生物使用的能量，并将其与整个含水层的水样测量结果进行比较。在另一个实验中，我们使用一个建造的地下水室，我们将使用呼吸来告诉我们生物体对土壤或河水来源的碳增加的反应有多强烈。智力优势：这一建议将大大增加我们对生活在河流相连的河流洪泛区含水层中的生物的基本生物学的理解。2更广泛的影响：在西部，山谷和洪泛区是人口、农业和饮用水重叠的地方。通过观察原始含水层，这项研究将告诉我们地下水系统是如何工作的，这对理解人类的影响很重要。