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.

小溪和河流的流动不仅仅是水和溶解在其中的物质，它们还携带着一种复杂的小颗粒混合物，统称为沉积物。塞斯顿通常包括淤泥、粘土、有机物质和微生物，它们来自周围的土地或溪流本身产生的。暴雨过后，在浑浊的河流中，我们可以看到由溪流输送的松子的重要性，但对这些颗粒在溪流中的作用仍然知之甚少。然而，随着松林向下游移动，它可以发挥许多至关重要的作用，包括为溪流动物提供食物和能量，以及为沿海生态系统提供生命所需元素碳、氮和磷的来源。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，该项目将增加我们对细颗粒在溪流中传播时所起作用的理解。该项目的结果将有助于精确估计由河流颗粒从陆地带到海岸的碳、氮和磷。这些数据可以用来为全球地球系统模型提供信息。本科生和研究生将参与本研究。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几个本科课程，该团队开发的教育模块将公开提供。由于其组成的多样性，以及与能够捕捉时空动态的可靠采样相关的挑战，在流动水域中seston的作用和重要性未得到充分认识。该项目将增加对河流植被组成的了解，以及植被如何耦合河流中碳、氮和磷的运输。该团队将测试三个互补的假设，这些假设将扩大对海积层在河流通量中的作用的理解：1)海积层的组成取决于地质和气候的大陆尺度模式；2)林积是陆地和河流生物地球化学过程的综合信号，随季节或水文环境的变化而变化；3)集林的数量和质量将揭示河网尺度的过程，这些过程将源头与更大的河流连接起来。该项目将利用新的和正在进行的数据收集工作，在22个可涉水溪流和河流NEON站点测量集的质量和数量。这些数据将用于开发季节组成和跨季节运输、水文条件和NEON域的预测模型。通过揭示林集在河流碳和营养物质生物地球化学中的作用，在局部、区域和大陆尺度上，本文提出的工作将为参数化模型提供关键数据，进一步定义河流在全球生物地球化学循环中的作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。