Aquatic metabolism and carbon dioxide flux: Linking physical and biological processes in Amazon floodplains

大气中二氧化碳的变化受到湿地植物和微生物活动的影响。湿地是温室气体的主要自然来源。亚马逊盆地拥有地球上面积最大的热带湿地。该地区的湿地由漂浮的草、被洪水淹没的森林和被高地雨林包围的湖泊组成。人类活动和环境变化正在改变亚马逊地区的景观。这些变化如何影响湿地，对于理解全球碳循环至关重要。亚马逊大部分地区的辽阔和偏远限制了人们对这一点的理解。该项目将利用新的卫星技术绘制洪水地图，并测量亚马逊湿地的范围。这项研究还将应用新技术来测量偏远地区的温室气体排放。这些新方法将产生关于造成湿地温室气体排放的生物活动的关键知识。结果将导致更好的资源管理战略，并改进对全球二氧化碳排放的核算。此外，该项目将为博士后科学家和研究生提供研究全球碳循环的前沿技术方面的培训。内陆水生生态系统，包括湿地，对碳循环和温室气体排放有很大和不成比例的影响。预测人类活动和环境变化将如何改变热带湿地(如亚马逊盆地的湿地)的碳循环，需要将密集的现场测量与遥感和数学模型相结合。湿地和大气之间二氧化碳等温室气体的交换取决于水动力、化学和生物过程。这项研究旨在检验这样一种假设，即亚马逊湿地释放到大气中的大部分二氧化碳代表着循环的水生生产力，而不是来自旱地的有机物质的横向运输。为了验证这一假设，该项目应用了最先进的湍流测量、温室气体通量测量，以及对洪泛区和水生植物的遥感。水生和陆地有机物质来源的区别对于预测土地利用和气候变化对湿地温室气体通量的影响至关重要。这一奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Changes in carbon dioxide in the atmosphere are influenced by the activities of wetland plants and microbes. Wetlands are a major natural source of greenhouse gases. The Amazon basin contains the largest area of tropical wetlands on Earth. Wetlands in this region consist of floating grasses, flooded forests and lakes surrounded by upland rainforests. Human activities and environmental changes are changing the landscape in the Amazon. How these changes affect wetlands is critical for understanding the global carbon cycle. The immense size and remoteness of much of the Amazon has limited this understanding. This project will take advantage of new satellite technology to map flooding and measure the extent of wetlands in the Amazon. This research will also apply new techniques to measure greenhouse gas emissions in remote locations. These new approaches will produce critical knowledge on biological activities responsible for wetland greenhouse gas emissions. The results will lead to better resource management strategies, and improved accounting of global carbon dioxide emissions. In addition, this project will provide training for postdoctoral scientists and graduate students in cutting-edge technologies for studying global carbon cycling. Inland aquatic ecosystems, including wetlands, have a large and disproportionate impact on carbon cycling and greenhouse gas emissions. Predicting how human activities and environmental changes will alter carbon cycling in tropical wetlands, such as those in the Amazon basin, requires combining intensive field measurements with remote sensing and mathematical models. The exchange of greenhouse gases, such as carbon dioxide, between wetlands and the atmosphere depends on hydrodynamic, chemical and biological processes. This research is designed to test the hypothesis that most of the carbon dioxide released to the atmosphere from Amazonian wetlands represents recycled aquatic productivity rather than lateral transport of organic matter from uplands. To test this hypothesis, the project applies state-of-the-art measurements of turbulence, fluxes of greenhouse gases, and remote sensing of flooded areas and aquatic plants. The distinction between aquatic and terrestrial sources of organic matter is critical to predicting the impacts of changes in land-use and climate on wetland greenhouse gas fluxes.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.