CAREER: Transformation and Transport of Organic Carbon in the Colorado River-Reservoir System

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 河流是陆地生态系统和水生生态系统之间的动态联系。河流中有机碳的产生、消耗和转化的生态地球化学过程对于理解区域碳收支、河流水质控制以及最终将陆地有机碳输出到沿海地区至关重要。我们对河流碳循环的基本理解主要基于原始河流的数据;然而，今天几乎所有的河流都被管理以优化供水，防洪和水力发电。在科罗拉多河上，水坝和水库系统极大地改变了水动力学和地貌、水停留时间、颗粒负荷、光照条件和沉积物-水相互作用。关于这些储层对碳地球化学的影响，我们所知相对较少。该项目将评估单一流域内一系列特征良好的水库沿线陆地和河流碳沿着的分布、组成和反应性。 这个CAREER项目整合了假设驱动的地球化学研究问题，最先进的分析方法和创新的教学策略，以解决三个基本的研究要素：1。结合实地测量和实验室操作实验，为科罗拉多河系统制定区域碳预算。研究科罗拉多河系统中溶解和颗粒有机碳的组成、反应性和命运。通过实地教学提高地球科学专业学生的学习成果，纵向水取样、碳特征和生物地球化学过程研究，最终得出每个水库的碳预算，将评估河流系统的营养状态，并揭示转化陆地和河流碳的生物和物理化学机制之间相互作用的新见解。研究和教学将通过基于探究的学生实地项目进行整合，这些项目解决了与更广泛的科学目标互补的离散问题;学生的结果将被整合到课堂活动中，增强了数百名其他学生的科学教育。该项目将为本科生地球科学家提供技能，以解决复杂的环境问题，使他们在学术生涯的早期阶段进行实地研究。科罗拉多河流系统提供了一个独特的机会，研究一个大型的管理河流，这项工作的结果将提供洞察支持当代河流系统中的碳循环的地球化学机制。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Rivers are the dynamic link between terrestrial and aquatic ecosystems. The biogeochemical processes that produce, consume, and transform organic carbon in rivers are critical to understanding regional carbon budgets, the controls on river water quality, and ultimately the export of terrestrial organic carbon to coastal regions. Our basic understanding of river carbon cycling is based largely on data from pristine rivers; yet today virtually all rivers are managed to optimize water supply, flood control and hydropower. On the Colorado River a system of dams and reservoirs has dramatically altered hydrodynamics and geomorphology, water residence time, particle load, light conditions, and sediment-water interactions. Comparatively little is known about the effects of these reservoirs on carbon biogeochemistry. This project will assess the distribution, composition and reactivity of terrestrial and riverine carbon along a sequence of well-characterized reservoirs in a single watershed. This CAREER project integrates hypothesis-driven biogeochemical research questions, state-of-the-art analytical approaches, and innovative teaching strategies to address three fundamental research elements: 1. Developing a regional carbon budget for the Colorado River System using a combination of field measurements and laboratory manipulation experiments.2. Examining the composition, reactivity, and fate of dissolved and particulate organic carbon in the Colorado River System.3. Enhancing learning outcomes for geoscience students through field-based teaching.Longitudinal water sampling, carbon characterization, and biogeochemical process studies, culminating in a carbon budget for each reservoir, will assess the trophic state of the river system and reveal new insights into the interactions among the biological and physico-chemical mechanisms that transform terrestrial and riverine carbon. The research and teaching will be integrated through inquiry-based student field-projects that address discrete questions complementary to the broader scientific objective; the students results will be integrated into classroom activities, enhancing science education for hundreds of other students. This project will provide undergraduate geoscientists the skills to address complex environmental problems by exposing them to field-based research at an early stage in their academic career. The Colorado river system provides a unique opportunity to study a large managed river, and the results of this work will provide insight for the biogeochemical mechanisms that support carbon cycling in contemporary river systems.