Collaborative Research: LTREB Renewal - River ecosystem responses to floodplain restoration

泛滥平原是指河流沿岸受水流影响的地区。洪泛区为人们提供了许多重要的好处，但它们也容易受到洪水、污染和其他干扰等变化的影响。了解受金属污染影响的河流生态系统长期变化的影响极其重要。该项目研究了蒙大拿州上克拉克福克河十年来的变化，在此之前，一个大型项目恢复了植被，并在河流源头广泛开采造成破坏后清除了受污染的土壤。土地利用和废水处理的变化也改变了河流沿线的氮和磷浓度。自2013年以来，修复了近17公里的河流，收集了三个核心数据集，这些数据集是在修复之前几十年启动的。这项研究的长期测量和空间尺度为观察恢复实践中涉及的生态过程提供了机会。作为该项目的一部分，几名本科生和研究生接受了教育，数据向公众开放，并通过克拉克福克科学论坛与该河流系统的许多利益相关者分享结果。蒙大拿州克拉克福克河上游的研究系统具有几个独特的品质，使该项目能够取得重大的科学进步。首先，该系统收到了大量金属投入，但自那以来这些投入已经停止。这使得能够随着时间的推移对生态系统动态进行调查，以响应这种停止。其次，研究人员密切观察了十年时间尺度上的生态和生物地球化学反应，这是研究河流生态系统恢复所涉及的缓慢过程类型的合适时间框架。该项目产生的核心数据集包括：1)对有机质和沉积物金属的影响，2)沉积物金属上下游梯度的变化，3)春季洪水脉冲与夏季基流期间恢复河段洪泛区重新连接的代谢响应，4)与溶解有机质相互作用引起的金属生物有效性的变化，以及5)河流恢复和未恢复部分的氮、磷和溶解有机碳的测量。最终，该项目调查了大空间(200公里)和时间(十年)尺度上的河流生态系统响应。该奖项反映了NSF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。

Floodplains are the areas alongside rivers that are affected by water movement. Floodplains provide many important benefits to people, yet they are also susceptible to changes such as flooding, pollution, and other disturbances. Understanding the effects of long-term changes in river ecosystems affected by metal pollution is extremely important. This project studies changes over ten years in the Upper Clark Fork River in Montana following a large project that restored vegetation and removed contaminated soil after damage from extensive mining in the river’s headwaters. Changes in land use and wastewater treatment are also altering nitrogen and phosphorus concentrations along the river. Since 2013, nearly 17 km of river has been restored and three core data sets have been collected, which were initiated decades before the restoration. The long-term measurements and the spatial scale of the study provides an opportunity to observe the ecological processes involved in restoration practices. Several undergraduate and graduate students are educated as part of this project, data are made available to the public, and results are shared with many stakeholders in this river system through the Clark Fork Science Forum.The study system of the Upper Clark Fork River in Montana, has several unique qualities that enable this project to make significant scientific advances. First, the system has received high inputs of metals that have since ceased. This enables investigation of the ecosystem dynamics over time in response to this cessation. Second, the investigators have closely observed ecological and biogeochemical responses over decadal timescales, which is the appropriate timeframe to study the types of slow processes involved in river ecosystem recovery. The project generates core data sets including: 1) influences on organic matter and sediment metals, 2) changes in upstream-downstream gradients in sediment metals, 3) metabolic responses to floodplain reconnection in restored reaches during the spring flood pulse vs. summer baseflow, 4) changes in metal bioavailability caused by interaction with dissolved organic matter, and 5) measurements of nitrogen, phosphorus, and dissolved organic carbon in restored and unrestored parts of the river. Ultimately, this project investigates river ecosystem responses over large spatial (200 km) and temporal ( decadal) scales.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.