Collaborative Research: Quantifying feedbacks between fluvial morphodynamics and pioneer riparian vegetation in sand-bed rivers

合作研究：量化沙床河流中河流形态动力学与先锋河岸植被之间的反馈

• 批准号: 1024820
• 负责人: John Stella
• 金额: $ 20.57万
• 依托单位: SUNY College of Environmental Science and Forestry
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1024820&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; feedbacks; between

In dynamic river ecosystems, riparian vegetation interacts with flow, sediment transport, and deposition, resulting in the coevolution of channel forms and vegetation communities. This project will develop a mechanistic and predictive understanding of interactions and feedbacks between vegetation and stream-channel processes in sand-bed rivers. The project addresses two broad questions: (1) how do woody plants affect flow and sediment transport individually and collectively, and (2) how do flow and sediment transport processes influence the mortality of riparian plants with different morphological traits? Integrated laboratory, field, and computational approaches will be employed to represent varying scales of space, time, and ecosystem complexity. Flume and mesocosm experiments will test the effect of vegetation on flow and sediment transport around individual plants and within vegetation patches, and the reciprocal effect of flow on plant removal via scour and burial. In addition, a field-scale experimental facility, the Outdoor Stream Lab at the University of Minnesota, will be used to test feedbacks between vegetation patches and bathymetry, flow, and sediment transport in a meandering sand-bed channel. Field investigations in a regulated, sand-bed reach of the Bill Williams River in western Arizona with a mixed native and invasive riparian community will combine high-resolution measurements of topography and vegetation before and after dam-controlled flood events with high-flow measurements of hydraulics and sediment flux. Finally, computational modeling will be used to synthesize and generalize field efforts. Two-dimensional flow and sediment modeling, in which vegetation effects are parameterized based on laboratory and field observations, will evaluate feedbacks while simulating flow and vegetation management scenarios. In addition, a riparian vegetation patch-dynamics model will be adapted to analyze community-level implications of species' differences in scour and burial mortality over multiple generations. This investigation will advance our knowledge of the co-evolution of physical processes and vegetation communities along rivers and will also inform river restoration and management efforts. This study will specifically address questions related to designing water releases from dams to benefit ecosystems. It will explore how reductions in sediment supply downstream of dams affect riparian vegetation and it will examine the mortality mechanisms of cottonwood and willow, which are dominant and ecologically important species along rivers in many semi-arid regions. It will also aid in the management of tamarisk, an invasive shrub that is prevalent along rivers in the western United States. By integrating novel experimental facilities, field study areas, and modeling methods, the project will advance our ability to understand and manage fluvial ecosystems.

在动态河流生态系统中，河岸植被与流量，沉积物传输和沉积相互作用，从而导致渠道形式和植被群落的同步。该项目将对沙床河中的植被和河道过程之间的相互作用和反馈进行机械和预测的理解。该项目解决了两个广泛的问题：（1）木本植物如何单独和集体影响流动和沉积物运输，以及（2）流动和沉积物传输过程如何影响具有不同形态特征的河岸植物的死亡率？将采用集成实验室，现场和计算方法来表示空间，时间和生态系统复杂性的不同尺度。 Flume和Mesocosm实验将测试植被对单个植物周围和植被斑块周围流量和沉积物的影响，以及流动对通过冲洗和埋葬进行植物清除的相互影响。此外，明尼苏达大学的户外溪流实验室将使用现场规模的实验设施来测试植被斑块和测深，流量，流量和沉积物在蜿蜒的砂床通道中的反馈。在亚利桑那州西部的比尔·威廉姆斯河（Bill Williams River）的一场受监管的，侵入性河岸社区的野外调查中，将在大坝控制的洪水事件之前和之后结合高分辨率的地形和植被的高分辨率测量以及对高流量的测量液压和沉积物通量。最后，计算建模将用于合成和概括现场工作。二维流量和沉积物建模，其中植被效应是根据实验室和现场观测来参数化的，将评估反馈，同时模拟流量和植被管理方案。此外，将适应河岸植被斑块模型模型，以分析社区级别对物种在多代的冲刷和埋葬死亡率差异的影响。这项调查将促进我们对河流物理过程和植被群落的共同发展的了解，还将为河流的恢复和管理工作提供信息。这项研究将专门解决与设计水坝的水释放有关的问题，以使生态系统受益。它将探讨大坝下游的沉积物供应减少如何影响河岸植被，并将检查杨木和柳树的死亡率机制，这些木材和柳树的死亡率机制在许多半干旱地区沿河流沿河流占主导地位且在生态上重要的物种。它还将有助于管理Tamarisk，这是一种侵入性灌木，在美国西部河流沿岸很普遍。通过整合新的实验设施，现场研究领域和建模方法，该项目将提高我们理解和管理河流生态系统的能力。