Development of an eco-geomorphic modeling framework to evaluate riparian ecosystem response to flow-regime changes
Development of an eco-geomorphic modeling framework to evaluate riparian ecosystem response to flow-regime changes
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DOI：
10.1016/j.ecoleng.2018.08.024
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发表时间：
2018-11-01
影响因子：
3.8
通讯作者：
Scott, Julian A.
中科院分区：
文献类型：
--
作者：
Diehl, Rebecca M.;Wilcox, Andrew C.;Scott, Julian A.
为决策者提供了解生态系统对径流属性变化的反应的工具是平衡人类和生态系统水需求所必需的。流量响应曲线提供了一种基于环境控制（例如，洪水量级）和响应（例如，植物补充）变量，虽然单向关系可能无法捕捉河岸生态系统中的生态和物理过程之间的复杂相互作用。我们利用植物功能性状之间的联系，重要的是（a）确定植物的环境条件的反应和（B）预测其对水流和泥沙输运的影响，建立一个预测模型的河岸生态系统动态。通过使用植物官能团（即，行会），我们的模型占径流属性，物理过程，植物群落响应之间的过程联系。该模型依赖于一系列的流量响应曲线，建立和测试的数据收集沿着半干旱，峡谷的河流在科罗拉多。我们建立了二维水动力学模型，并更新了一个灵活的植被模块，以代表三个研究河段的植物-水力相互作用。该模型较好地描述了植物的功能团分布，而对地形变化的发生和方向的预测则不太确定。我们的工作是第一批在同一框架内为物理和生态过程开发响应曲线的工作之一。由此产生的曲线的形状表明，河岸生态系统的功能是由非线性关系，明确的，可识别的阈值存在。因此，水流状态的变化将对物理和生态过程产生不同的影响，这取决于转变的性质。我们讨论了我们模型的优点和局限性，并就其对河流管理的适用性提出了建议。
Tools that provide decision makers with an understanding of ecosystem response to changes in streamflow attributes are necessary to balance human and ecosystem water needs. Flow response curves provide one such approach for informing management based on modeled relationships between environmental control (e.g., flood magnitude) and response (e.g., plant recruitment) variables, although unidirectional relationships may fail to capture the complex interactions between ecological and physical processes in riparian ecosystems. We take advantage of the linkage between plant functional traits important for (a) determining a plant's response to environmental conditions and (b) for predicting its impact on the flow of water and transport of sediment, to build a predictive model of riparian ecosystem dynamics. By using plant functional groups (i.e., guilds), our model accounts for process linkages among streamflow properties, physical processes, and plant community response. The model relies on a series of flow response curves built and tested with data collected along semiarid, canyon-bound rivers in Colorado. We built 2D hydrodynamic models and updated them with a flexible vegetation module to represent plant-hydraulic interactions for three study reaches. Plant guild distributions are well described by the model while predictions of the occurrence and direction of topographic change are less deterministic. Our work is among the first to develop response curves for both physical and ecological processes in the same framework. The shape of the resulting curves indicate that the functioning of riparian ecosystems is driven by nonlinear relationships and that clear, identifiable thresholds exist. As such, changes to the flow regime will have a differential impact on physical and ecological processes, depending on the nature of the shift. We discuss the strength and limitations of our model and make suggestions about its applicability to river management.