Collaborative Research: Organic Carbon Dynamics and Trophic Pathways in a Low-Gradient River-Floodplain Ecosystem

研究了水文条件和温度对低梯度黑水河流-漫滩生态系统生产和分解过程的影响。本研究的主要目标是建立一个模型来预测绿色植物生产的规模，以及这些生态系统中与消费者和分解者活动相关的碳（能量）动态作为非生物条件的函数。以前nsf资助的研究结果将提供构建模型所需的大部分数据。将进行新的实地和实验室研究，以提供对模型构建工作至关重要的数据，但在Meyer和Benke开发的现有数据集或文献中都无法获得。在过去的六年里，Meyer和Benke研究了乔治亚州下游沿海平原的Ogeechchee河及其泛滥平原的有机碳动态和营养途径。在这项新研究中，他们将在一个模型中综合他们之前的工作，该模型使用两个非生物“驱动”变量，“流体动力制度”和温度来预测系统的一系列生物特征，包括；系统初级生产和呼吸，次级生产，和细菌的动态。如果这个模型是精心设计的，它将是一个有用的工具，可以清楚地勾勒出美国东南部黑水河流的生物可能受到的影响，比如筑坝和疏浚，以及与发电厂冷却有关的热状态变化。新的实地和实验室研究将解决以下问题：河流水柱中溶解有机碳对细菌的可利用性；原生动物通过食用控制细菌数量的作用；原生动物作为大型无脊椎动物食物来源的重要性在洪泛区是重要的次生产物。这项新的研究是我们了解黑水河流结构和功能的关键。进行这些研究的研究团队很强大。Drs。迈耶斯和本克是经验丰富的河流生态学家，韦格特博士是建模任务的顾问，也是世界公认的生态建模师。该项目的机构设置将为同事和相关研究提供良好的科学互动和协同环境。生态系统研究项目建议授予该资助。

The influence of both hydrologic regime and temperature on production and decomposition processes in low-gradient blackwater river-floodplain ecosystems will be investigated. The major goal of this research is to develop a model to predict the magnitude of green plant production, and the carbon (energy) dynamics associated with consumer and decomposer activities in these ecosystems as a function of abiotic conditions. Results from previous NSF-funded research will provide most of the data neededto build the model. New field and laboratory research will be conducted to supply data that is essential to the model- building effort, but is unavailable either in extant data sets developed by Meyer and Benke or in the literature. For the past six years Meyer and Benke have studied the organic carbon dynamics and trophic pathways in the Ogeechchee River and its floodplain in the lower coastal plain of Georgia. In this new research they will synthesize their previous work in a model that uses two abiotic "driving" variables, "hydrodynamic regime" and temperature to predict a series of biotic characteristics of the system including; system primary production and respiration, secondary production, and the dynamics of bacteria. If the model is carefully crafted it will be a useful tool for clearly outlining the possible affects on the biology of black water rivers of the southeastern United States of disturbances such as damming and dredging, and changes in thermal-regime like those associated with power-plant cooling. New field and laboratory research will address the following issues: availability of dissolved organic carbon to bacteria in ariver's water column; the role of protozoa in controlling bacterial populations through consumption; the importance of protozoa as food sources for macroinvertebrates; and the importance secondary production in the floodplain. This new research is key to our understanding of the structure and function of blackwater rivers. The research team that will conduct these studies is strong. Drs. Meyers and Benke are experienced stream ecologists, and Dr. Weigert, a consultant on the modeling task, is a world- recognized ecological modeler. The institutional settings for the project will provide excellent scientific interaction and a synergistic environment of colleagues and related research. The Ecosystem Studies Program recommends award of this grant.