Application of biomarkers to examine transformations of dissolved carbon and nitrogen reservoirs in Arctic rivers

职务名称：应用生物标志物研究北极河流中溶解碳和氮库的转化技术北极流域中储存的有机碳的绝对数量决定了了解其动态对于描述和模拟当前和未来变暖将如何影响北极生态系统的碳释放至关重要。北极河流携带着大量的溶解有机物（DOM），是连接陆地和海洋碳库的重要通道，对北冰洋生态地球化学循环具有重要影响。该提案利用地球化学方法研究北极河流中溶解有机碳（DOC）和氮（DON）库的命运和转化。其目标是1）提供一个详细的分析，北极河流DOM的生物利用度在不同阶段的水文，2）调查的起源和转换的DON在北极河流。我们将结合联合收割机分子水平分析的碳水化合物，氨基酸，包括D-氨基酸，酚生物标志物与实验室培养实验收集的样品。在北极流域收集的新鲜沥滤垃圾的孵育实验将用于内部校准生物标志物。在这个项目中产生的数据将与大量已经测量的参数（50）相结合，以研究DOM源、分解、气候、水文和河流化学之间的联系。更广泛的意义和重要性在过去的12,000年里，北极地区的土壤和生物量积累了巨大的碳库。由于当前和预期的气候变化，这一巨大的碳库的转移对北极生态系统和全球气候的健康产生了重大影响。碳水化合物，氨基酸和酚类生物标志物的拟议应用将改善我们非常有限的了解北极河流中的有机成分的来源和转化过程，因为它们从土壤中运输到北冰洋。该提案还将调查有机化合物如何在不同的北极河流流域分解，这些流域具有不同的植被，地形，年平均气温以及不同流动条件和季节的永久冻土范围。了解来源（植被、土壤、泥炭等）如果我们想预测气候变暖对有机成分从这些流域转移到北冰洋的影响，那么有机成分的变化以及主要的转化过程（溶解、吸收、分解）至关重要。该项目将提供高影响力的学习经验，本科生从得克萨斯州A M在加尔维斯顿，并有助于一个开始调查的发展。这项研究的结果将广泛提供给科学界，以便数据集可用于构建从北极地区到北冰洋的有机碳转移的详细模型。

Title: Application of biomarkers to examine transformations of dissolved carbon and nitrogen reservoirs in Arctic riversTechnical.The sheer magnitude of organic carbon stored in Arctic watersheds dictates that understanding its dynamics is vital to describing and modeling how current and future warming will impact the release of carbon from Arctic ecosystems. Arctic rivers carry large quantities of dissolved organic matter (DOM) and represent an important conduit connecting terrestrial and oceanic carbon pools with a major impact on biogeochemical cycles in the Arctic Ocean. This proposal utilizes a geochemical approach to investigate the fate and transformations of dissolved organic carbon (DOC) and nitrogen (DON) reservoirs in Arctic rivers. The goal is 1) to provide a detailed analysis of the bioavailability of Arctic river DOM at the different stages of the hydrograph, and 2) to investigate the origins and transformations of DON in Arctic rivers. We will combine molecular level analysis of carbohydrates, amino acids including D-amino acids, and phenol biomarkers on collected samples with laboratory incubation experiments. The incubation experiments with fresh-leached litter collected in Arctic watersheds will be used to internally calibrate biomarkers. Data generated during this project will be integrated with a vast array of already measured parameters (50) to examine linkages among DOM sources, decomposition, climate, hydrology, and river chemistry.Broader significance and importance.The Arctic regions have accumulated an immense reservoir of carbon in soils and biomass over the last 12,000 years. A transfer of this enormous pool of carbon due to current and anticipated climate change has a major effect on the health of the Arctic ecosystem and global climate. The proposed application of carbohydrate, amino acids and phenolic biomarkers will improve our very limited understanding of sources and transformation processes of organic constituents in Arctic rivers as they are transported from soils to the Arctic Ocean. The proposal will also investigate how organic compounds decompose in different Arctic river watersheds with varying vegetation, topography, mean annual air temperature, and extent of permafrost at different flow conditions and seasons. Knowing the sources (vegetation, soil, peat etc.) of organic constituents as well as the dominant transformation processes (solution, absorption, decomposition) is crucial if we want to predict the effect that a warmer climate will have on the transfer of organic constituents from these watersheds to the Arctic Ocean. The project will provide high-impact learning experiences for undergraduate students from Texas A&M at Galveston and contribute to the development of one beginning investigator. Results from this research will be made widely available to the scientific community such that the data set may be used to construct detailed models of organic carbon transfer from Arctic regions to the Arctic Ocean.