Microbial Mediation of Organic Carbon Transformations in An Emergent Macrophyte-Dominated Habitat of the Okefenokee Swamp Ecosystem

将在一个新兴的大型植物中研究分解。主要栖息于乔治亚州东南部的奥克弗诺基沼泽生态系统。在这碎屑中。基于生态系统，新兴大型植物>Carex> >walteriana>的木质纤维素是最丰富的碳源。由于木质纤维素在很大程度上对动物来说是难以消化的，它们在被微生物降解之前无法利用其中的碳（能量）。因此，了解木质纤维素物质的微生物转化和控制其分解速率的因素是了解奥克弗诺基和其他湿地生态系统如何工作的关键。本研究将分为三个部分；详细的工艺研究，完整的系统。水平测量和建模综合。详细的过程研究将侧重于分解在现场和实验室的努力，旨在阐明转化，命运和控制分解的时间和空间方面，不仅是木质纤维素，而且是非木质纤维素。木质纤维素的碳。在这些研究中使用的技术包括：用。1.4 c对底物进行放射性标记，以确定分解物质的命运；以及给细菌贴上ı.3H！胸苷测定颗粒掺入效率。这个系统。水平测量的目的是将分解研究置于场地整体碳预算的背景下。标准方法包括流程。通过代谢室和1.4 c“尖刺”光。暗瓶将用于系统级研究。在本研究中，建模将起到综合工具的作用。现有的微生物降解木质纤维素的模型将扩展到：1)考虑与碎屑输入有关的腐烂的空间和时间方面；2)对包括氮、磷和硫的影响在内的衰变速率进行更明确和详细的控制。最后，将对修改后的模型进行详细的流动和敏感性分析。这项研究的意义在于，它将帮助我们了解湿地这一全球主要生态系统类型的功能。该研究为合理管理这一重要地貌提供了科学依据。Drs。霍德森、维格特和霍普金森都是非常有能力的科学家，有着丰富的研究记录。向他们提供的体制支持是极好的。

>> Decomposition will be studied in an emergent macrophyte.dominated habitat of the Okefenokee Swamp ecosystem in southeastern Georgia. In this detritus.based ecosystem, lignocellulose from the emergent Macrophyte >Carex> >walteriana> is the most abundant source of carbon. Since lignocellulose is largely indigestible to animals they cannot use its carbon (energy) until it is degraded by microorganisms. Thus, having an understanding of microbial transformations of lignocellulosic material and the factors controlling rates of its breakdown are key to understanding how the Okefenokee and other wetland ecosystems work. The research will be divided into three parts; detailed process studies, integrative system.level measurements, and modeling syntheses. The detailed process studies will focus on decomposition in field and laboratory efforts designed to clarify the temporal and spatial aspects of transformations, fate, and controls on decomposition not only of lignocellulosic, but also of non.lignocellulosic carbon. Techniques to be used in these studies include: the radiolabeling of substrates with .1.4C to determine the fate of the decomposed material; and the labeling of bacteria with ı.3H! thymidine to determine the efficiency of particle incorporation. The system.level measurements are designed to put the decomposition studies in context of the site's overall carbon budget. Standard methods including flow.through metabolic chambers and .1.4C "spiked" light.dark bottles will be used in the system level studies. Modeling will function as a synthesis tool in this research. Extant models of microbial degradation of lignocellulose will be expanded to: 1) consider spatial and temporal aspects of decay related to detrital inputs; and 2) incorporate more explicit and detailed controls on rates of decay including the influence of N, P and S. Finally, detailed flow and sensitivity analyses will be made of the modified models. The significance of this research is that it will help us to understand how wetlands, a major ecosystem type, worldwide, function. This research should provide a scientific basis for wise management of this important landform. Drs. Hodson, Wiegert and Hopkinson are very capable scientists with strong research records. The institutional support available to them is excellent.