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

将研究水文状况和温度对低坡度黑水河漫滩生态系统生产和分解过程的影响。这项研究的主要目标是开发一个模型来预测这些生态系统中绿色植物产量的大小，以及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。之前NSF资助的研究结果将提供建立该模型所需的大部分数据。将进行新的实地和实验室研究，以提供对建立模型工作至关重要的数据，但这些数据无论是在Meyer和Benke开发的现有数据集中还是在文献中都无法获得。在过去的六年里，迈耶和本克研究了奥格切奇河及其位于佐治亚州低海岸平原的泛滥平原的有机碳动态和营养途径。在这项新的研究中，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，“水动力状态”和温度来预测系统的一系列生物特征，包括：系统的初级生产和呼吸、次级生产和细菌的动态。如果仔细设计这个模型，它将是一个有用的工具，可以清楚地勾勒出筑坝和疏浚等扰动对美国东南部黑水河流生物的可能影响，以及与发电厂冷却相关的热状况变化。新的实地和实验室研究将涉及以下问题：河流水体中细菌对溶解有机碳的有效性；原生动物通过消费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；以及洪泛平原次生生产的重要性。这项新的研究对我们理解黑水河的结构和功能至关重要。将进行这些研究的研究团队很强大。迈耶斯博士和本克博士是经验丰富的河流生态学家，魏格特博士是建模任务的顾问，是世界公认的生态建模专家。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。生态系统研究计划建议授予这笔赠款。

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.