Collaborative Research: Continuous Metabolism and Nutrient Uptake Across the River Continuum

河流是连接陆地和海洋的主要通道，输送水、沉积物和营养物质。当水流经河网时，它所携带的物质随着物理、化学和生物特性的变化而被运输、储存、加工和释放。该项目的目标是更好地了解河流系统如何处理碳，保留营养物质，影响全球生态系统健康，并最终支持河流及其排入水体的健康生态系统。河流生态系统科学建立的一个概念是，河流的特征和加工速度会随着下游的大小和/或距离而变化。这个想法被称为河流连续体概念（RCC），它帮助组织了几十年的河流研究和管理。然而，尽管RCC是一个有用的概念模型，但它仍然相对缺乏测试，这严重限制了科学家预测河流功能如何响应地球上正在发生的和未来的变化的能力。这项工作旨在填补关于河流如何发挥作用的重要知识空白，从而对人类如何管理土地和水资源产生影响。提供沿河流连续体的河流功能信息的一个限制是技术；我们只是没有工具来测量河流网络的这些功能。第二个限制是，碾压混凝土的简单概念模型忽略了河流的关键特征，特别是它们经常受到水坝和湖泊、支流汇合处和地质分界线等不连续的影响。该项目通过将最先进的水质传感器技术与精心选择的河流地点的新采样方法相结合，减轻了这两种限制。总之，这些进展有望提供关于河流连续体的新见解，不连续性在改变河流功能中的作用，并最终关于如何最好地管理和保护水生资源。

Rivers are the major pathways connecting the land to the sea, conveying water, sediments and nutrients. As water flows through river networks, the materials it carries are transported, stored, processed, and released in response to changing physical, chemical and biological characteristics. The goal of this project is to better understand how river systems process carbon, retain nutrients, influence ecosystem health globally, and ultimately support healthy ecosystems, both in the rivers and the water bodies into which they drain. One of the concepts upon which river ecosystem science is founded is that rivers change their characteristics and processing rates with size and/or distance downstream. This idea, called the River Continuum Concept (RCC), has helped organize decades of river research and management. However, while the RCC has been a useful conceptual model, it remains relatively poorly tested, which seriously limits the ability of scientists to predict how river functions will respond to ongoing and future changes on Earth. This work seeks to fill that important knowledge gap about how rivers function, and thus has implications for how humans manage land and water resources.One constraint to providing information about river function along the river continuum has been technological; we simply have not had the tools to measure these functions along river networks. A second constraint has been that the simple conceptual model of the RCC neglects key features of rivers, specifically that they are frequently impacted by discontinuities like dams and lakes, tributary confluences, and geologic divides. This project alleviates both constraints by coupling state-of-the-art water quality sensor technologies to new sampling methods in carefully selected river sites. Together, these advances are expected to provide new insights about the river continuum, the role of discontinuities in changing river functions, and ultimately about how to best manage and protect aquatic resources.