Collaborative Research: MRA: ConFines: Continental-scale study of the role of fine particles in riverine material fluxes

合作研究：MRA：ConFines：大陆尺度研究细颗粒在河流物质通量中的作用

• 批准号: 2106075
• 负责人: David Manning
• 金额: $ 24.42万
• 依托单位: University of Nebraska at Omaha
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106075&HistoricalAwards=false
• 关键词: Collaborative; Research; MRA; ConFines; Continental

Streams and rivers move more than water and the material dissolved in it—they also carry a complex blend of small particles, collectively called seston. Seston typically includes silt, clay, organic material, and microbes that originate from the surrounding land or that are produced within the stream itself. While the significance of seston transported by streams can be seen in a muddy river after a rainstorm, the function of these particles in streams remains poorly understood. However, as seston moves downstream it can serve many crucial roles, including as food and energy for stream animals and as a source of the life-building elements carbon, nitrogen, and phosphorus for coastal ecosystems. Using field samples and high-frequency water quality data from environmental sensors at National Ecological Observatory Network (NEON) sites, this project will increase our understanding of the role of fine particles as they travel in streams. Results from the project will help to refine estimates of carbon, nitrogen, and phosphorus carried from the land to the coast by riverine particles. These data can be used to inform global earth-system models. Undergraduate and graduate students will participate in this research. NEON data will be used to introduce data-science techniques, computer modeling, and graphical analysis into several undergraduate courses and educational modules developed by the team will be made publicly available. The role and importance of seston in flowing waters is underappreciated, both because of its diverse composition and because of challenges associated with robust sampling capable of capturing spatial and temporal dynamics. This project will increase understanding of riverine seston composition as well as how seston couples carbon, nitrogen, and phosphorus transport in rivers. The team will test three complementary hypotheses that will expand understanding of the role of seston in riverine fluxes: 1) seston composition depends on continental-scale patterns in geology and climate; 2) seston is an integrated signal of terrestrial and in-stream biogeochemical processes that varies according to seasonal or hydrologic context; and 3) seston quantity and quality will reveal river network-scale processes that connect headwaters to larger rivers. This project will leverage new and ongoing data collection efforts at 22 wadeable-stream and river NEON sites to measure seston quality and quantity. These data will be used to develop predictive models for seston composition and transport across seasons, hydrologic conditions, and NEON domains. By shedding light on the role of seston in riverine carbon and nutrient biogeochemistry at the local, regional, and continental scale, the work proposed here will provide key data needed to parameterize models that further define the role of rivers in global biogeochemical cycles.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.

溪流和河流移动的不仅仅是水和溶解在其中的物质，它们还携带着复杂的小颗粒混合物，统称为塞斯顿。塞斯顿通常包括淤泥、粘土、有机物质和微生物，这些物质源自周围的土地或溪流本身产生的。虽然在暴雨后的泥泞河流中可以看到溪流输送的塞斯顿的重要性，但这些颗粒在溪流中的功能仍然知之甚少。然而，当塞斯顿向下游移动时，它可以发挥许多关键作用，包括作为溪流动物的食物和能量，以及作为沿海生态系统生命构建元素碳、氮和磷的来源。该项目利用国家生态观测网络 (NEON) 站点环境传感器的现场样本和高频水质数据，将加深我们对细颗粒在溪流中移动时所起作用的了解。该项目的结果将有助于完善对河流颗粒从陆地携带到海岸的碳、氮和磷的估计。这些数据可用于为全球地球系统模型提供信息。本科生和研究生将参与这项研究。 NEON 数据将用于将数据科学技术、计算机建模和图形分析引入到多个本科课程中，并且该团队开发的教育模块将公开发布。塞斯顿在流动水中的作用和重要性未被充分认识，这既是因为其成分多样，也是因为能够捕获空间和时间动态的稳健采样所面临的挑战。该项目将增进对河流塞斯顿成分以及塞斯顿如何耦合河流中碳、氮和磷运输的了解。该团队将测试三个互补的假设，这些假设将扩大对塞斯顿在河流通量中的作用的理解：1）塞斯顿的组成取决于地质和气候的大陆尺度模式； 2) seston 是陆地和河流内生物地球化学过程的综合信号，根据季节或水文背景而变化； 3）水量和质量将揭示连接源头与较大河流的河网规模过程。该项目将利用 22 个可涉水溪流和河流 NEON 站点的新的和正在进行的数据收集工作来测量水流的质量和数量。这些数据将用于开发跨季节、水文条件和 NEON 领域的水滴组成和传输的预测模型。通过阐明塞斯顿在地方、区域和大陆尺度河流碳和养分生物地球化学中的作用，这里提出的工作将提供参数化模型所需的关键数据，进一步定义河流在全球生物地球化学循环中的作用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持 标准。