Dynamics of Carbon Export to the Atmosphere and Oceans from Fluvial Systems of the Humid Tropics: Southeast Asia

湿润热带河流系统向大气和海洋的碳输出动态：东南亚

• 批准号: 0223521
• 负责人: Jeffrey Richey
• 金额: --
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0223521&HistoricalAwards=false
• 关键词: Dynamics; Carbon; Export; Atmosphere; Oceans

AbstractThe overall question we are addressing in this proposal is, "What role does the evasion (outgassing) of CO2 from the river system to the atmosphere play relative to fluvial carbon export to the ocean in the carbon cycle of the humid tropics?" We have recently demonstrated that outgassing of CO2 from rivers and wetlands of the central Amazonian basin is 1.2 0.3 Mg C ha -1 y -1 , or, when extrapolated across the entire basin, an order of magnitude greater than fluvial export of organic carbon to the oceans. Such a flux would be an important loss, as it is approximately equal to lower estimates of carbon sequestration in the Amazon. These conclusions lead to the working hypothesis for this proposal, that Surface water CO2 evasion is the dominant source of carbon loss (exceeding export to the oceans by a factor of 10) in fluvial systems of the humid tropics, and in the aggregate reconciles the tropics in the global carbon budget. Evasion is driven primarily by in-stream respiration of organic carbon translocated in space and time from its terrestrial and riparian origins. While estimates are becoming better constrained in the Amazon, they are not elsewhere in the tropics, particularly in regions of much greater anthropogenic impact.With this proposal we intend to extend and test our Amazon-based working hypothesis to another significant region, Southeast Asia. We propose to (1) enhance an existing model with improved water routing and inundation, sediments, and carbon modules as a function of landscape condition, (2) conduct a field sampling campaign to determine region-specific processes and provide data for model validation, and (3) use the resulting improved model to analyze questions concerning the dynamics of carbon in the fluvial environments of Southeast Asia which will test our working hypothesis.The most significant intellectual merit of our proposal is (1) that a significant anomaly in the global carbon cycle is being addressed, and (2) the work represents a convergence of historically separate lines of earth science into a significant "new" view of the global importance of the processes and magnitudes of land-water-atmosphere coupling. The most important broader impact of the work will most likely come via improved tools and information networks for "sustainability" in a region of multiple transboundary environmental pressures.

AbstractThe总体问题，我们正在解决这个建议是，“什么样的角色？逃逸（释气）的CO2从河流系统到大气中发挥相对于河流的碳输出到海洋中的碳循环的潮湿热带地区？“我们最近已经证明，从亚马逊河流域中部的河流和湿地中释放的CO2为1.2 - 0.3 Mg C ha-1 y-1，或者，当外推到整个流域时，比河流向海洋输出的有机碳大一个数量级。这样的通量将是一个重大损失，因为它大约等于亚马逊地区较低的固碳估计数。这些结论导致了这项建议的工作假设，即地表水CO2逃逸是潮湿热带河流系统碳损失的主要来源（超过出口到海洋的10倍），并在总体上调和了热带地区的全球碳预算。逃逸主要是驱动流呼吸的有机碳在空间和时间从陆地和河岸起源。虽然估计是越来越好地限制在亚马逊，他们不是在热带地区的其他地方，特别是在更大的人为影响的地区。通过这个建议，我们打算扩展和测试我们的亚马逊为基础的工作假设到另一个重要的地区，东南亚。我们建议（1）通过改进水路由和洪水，沉积物和碳模块来增强现有模型，作为景观条件的函数，（2）进行实地采样活动以确定区域特定过程并为模型验证提供数据，以及（3）使用由此产生的改进模型来分析东南亚河流环境中碳动态的问题，这将测试我们的我们的建议最重要的智力价值是：（1）正在解决全球碳循环中的一个重大异常现象;（2）这项工作代表了地球科学历史上不同学科的融合，形成了陆地-水-大气耦合过程和程度的全球重要性的重要“新”观点。这项工作最重要的更广泛的影响很可能是通过改进工具和信息网络，在一个面临多重跨界环境压力的区域实现“可持续性”。