Carbon Deposition and Fluxes by Attached Aquatic Microbiota

这项研究评估了附着的水生微生物区系如何调节(1)从旱地地区进口的或由这些地区的水生植物和藻类合成的有机碳的沉积速率，以及(2)有机碳的保留率或损失率。微生物群通过将溶解的有机碳密集分解成二氧化碳和甲烷，以及通过掩埋大量不分解的微生物生物量来完成这一调节。高新陈代谢和生长是群落内营养物质密集循环的结果。该研究计划将在重复的实验条件下检查自然群落：(1)新陈代谢和群落碳的保持，以及在基质响应下分解为二氧化碳和甲烷。(2)磷、氮对养分限制的抗性及其对碳流失的影响。(3)不同类型溶解有机化合物对代谢循环和碳损失的影响。(4)测定附生群落内营养盐的横向微尺度通量。湖泊和河流生态系统的湿地/滨海和泛滥平原陆水交界区被认为是有机碳的主要沉积区。有机碳储存与以二氧化碳和甲烷形式存在的代谢碳的演化相比非常重要，因为这些“温室”气体对全球气候变化评估至关重要。*//

This research evaluates how attached aquatic microflora (periphyton) regulate (1) the rates of deposition of organic carbon that is imported from upland areas or synthesized by aquatic plants and algae in these regions , and (2) the retention or loss rates of organic carbon. The microbiota accomplish this regulation by a combination of intensive decomposition of dissolved organic carbon to CO2 and methane and by burying a significant portion of microbial biomass that does not decompose. High metabolism and growth results from intensive recycling of nutrients within the communities. The research program will examine natural communities under replicated experimental conditions for: (1) Metabolic and community carbon retention and decomposition to CO2 and methane in response to substratum. (2) Resistance to nutrient limitations of phosphorus and nitrogen and the effects on carbon losses. (3) Effects of different types of dissolved organic compounds on metabolic recycling and carbon losses. (4) Determination of lateral microscale fluxes of nutrients within these attached communities. %%% Wetland/ littoral and floodplain land-water interface regions of lake and river ecosystems are being recognized as major depositional areas for organic carbon. Organic carbon storage versus evolution of metabolized carbon in the form of CO2 and methane is important because these 'greenhouse' gases are critical to global climate change evaluations. ***//