CAREER: From the forest to the stream: Exploring forest land cover controls on dissolved organic matter character and aquatic ecosystem respiration in headwater streams

虽然内陆沃茨仅占地球表面的1%，但它们在全球碳循环中发挥着核心作用。大量的碳被输送到内陆沃茨作为陆地溶解有机物（DOM）在源头河流。这些河流中DOM的类型和数量控制着碳是释放到大气中（即河流呼吸）还是从碳循环中去除（即向下游运输和掩埋）。该项目将确定森林采伐，特别是皆伐在控制源头河流的碳循环和河流呼吸方面的作用。该项目的结果将用于开发预测模型，指导未来的研究，并为森林水源系统的管理提供信息。该项目将为至少2名博士和9名本科生研究人员提供培训，他们将获得水文和地球化学科学的跨学科专业知识，解决社会关注的问题。在这个项目中获得的数据和理解将被用作大学课堂的例子，讨论土地管理，碳循环和森林生态系统的水文响应之间的联系。该项目将编制流域科学教育材料，供近6，000名K-12学生、48名科学教师和40名职前学生使用，以提高对土地覆盖-生态系统相互作用的理解和对当地流域的了解。内陆沃茨最近因其在全球碳库和相对于陆地和海洋系统的通量中的重要性而受到重视。溶解有机物（DOM）是通过河流网络运输的有机碳的最大部分，其中大部分DOM进入河流的源头森林位置。该项目响应了《碳循环第二阶段报告》中提出的“更好地确定人类活动对内陆沃茨碳的运输和生态地球化学循环的影响”的号召，通过：1）确定森林采伐在调节源头河流DOM特征中的作用; 2）量化DOM特征对河流生态系统呼吸的影响;和3）确定组件1和2如何相互作用，以调节空间和时间模式的生态系统呼吸森林源流网络。这些信息将用于创建预测，然后将与数据进行比较，以改进模型，并揭示理解方面的差距，以指导未来的现场和实验室实验。该项目将开发一个垂直整合的导师，教育计划，并为本科生和博士生提供培训，他们将接触研究，推广和专业发展活动。通过与自然科学教育和外展中心学院的合作，该项目将开发一个关于流域科学的STEM工具包，专门针对K-12学校，这些学校的学生比例偏低，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

Although inland waters comprise only ~1% of Earth’s surface, they play a central role in the global carbon cycle. Large amounts of carbon are delivered to inland waters as terrestrial dissolved organic matter (DOM) in headwater streams. The type and amount of DOM in these streams controls whether that carbon is released to the atmosphere (i.e. stream respiration) or removed from the carbon cycle (i.e. transported downstream and buried). This project will determine the role of forest harvesting, and specifically clear cutting, in controlling carbon cycling and stream respiration in headwater streams. The results from this project will be used to develop predictive models that guide future research and inform management of forested headwater systems. This project will provide training for at least 2 PhD and 9 undergraduate student researchers who will gain interdisciplinary expertise in the hydrologic and biogeochemical sciences, solving problems of societal concern. Data and understanding gained in this project will be used as university class examples to discuss the linkages between land management, carbon cycling, and hydrologic response of forested ecosystems. This project will develop educational materials on watershed science that will reach nearly 6,000 K-12 students, 48 science teachers, and 40 pre-service students to enhance understanding of land cover-ecosystem interactions and knowledge of their local watersheds.Inland waters have recently been highlighted for their importance in global carbon pools and fluxes relative to terrestrial and marine systems. Dissolved organic matter (DOM) represents the largest fraction of organic carbon transported through stream networks, and much of this DOM enters streams in headwater forest locations. This project answers the call to ‘focus on better identifying human impacts on the transport and biogeochemical cycling of carbon by inland waters’ as outlined in the Second State of the Carbon Cycle Report, by: 1) Determining the role of forest harvesting in regulating DOM character in headwater streams; 2) Quantifying the influence of DOM character on stream ecosystem respiration; and 3) Identifying how components 1 and 2 interact to regulate spatial and temporal patterns of ecosystem respiration across forested headwater stream networks. This information will be used to create predictions that will then be confronted with data to improve models, and expose gaps in understanding to guide future field and lab experimentation. This project will develop a vertically integrated program of mentorship, education, and provide training for undergraduate and PhD students who will gain exposure to research, outreach, and professional development activities. Through collaboration with the College of Natural Science Education and Outreach Center, this project will develop a STEM kit on watershed science specifically targeted at K-12 schools with a high percentage of underrepresented students, and encourage these groups to pursue STEM pathways.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.