Biogeochemical Cycling in the Organic-Rich Coastal Environment

该项目关注的是一个对理解全球海洋碳循环至关重要的问题：什么因素和过程控制着沉积在海洋沉积物中的有机物是否会被再矿化或被掩埋。有机质沉积、再矿化和埋藏将在北卡罗来纳州一个浅层、高产的沿海泻湖和哈特拉斯角外的大陆上斜坡的样带进行研究。具体目标包括：(1)确定沿这两个海岸样带沉积的有机碳的再矿化部分是如何变化的；(2)确定活性部分的来源和年龄；(3)确定沿这些样带各地点的有机物质的活性和非活性部分的化学组成；(4)测定呼吸方式对埋地有机质再矿化速率和化学成分的影响。目标(1)、(2)和(3)涉及广泛的实地工作，而目标(4)涉及控制良好的实验室微观研究。结合现场数据和实验室实验提供了一个强大的工具，可以直接测试关于环境参数影响有机物反应性机制的假设。

The project focuses on a question of fundamental importance for understanding the global oceanic carbon cycle: What factors and processes control whether organic matter deposited in marine sediments will be remineralized or buried. Organic matter deposition, remineralization, and burial will be studied at sites along transects in a shallow, highly productive North Carolina coastal lagoon and on the upper continental slope off Cape Hatteras, NC. Specific objectives include: (1) determination of how the fraction of organic carbon deposition that is remineralized varies along these two coastal transects, (2) determination of sources and ages of the reactive fraction, (3) determination of the chemical composition of reactive and unreactive fractions of the organic matter at sites along these transects, and (4) determination of the effect of respiratory mode on organic matter remineralization rates and chemical composition of buried material. Objectives (1), (2), and (3) involve extensive field work while objective (4) involves as well-controlled laboratory microcosm study. Combining field data and laboratory experiments provides a powerful tool for directly testing hypotheses regarding the mechanisms by which environmental parameters influence organic matter reactivity.