Collaborative Research: Modeling the Impacts of Post-Settlement Sediment Deposition on Floodplain Vegetation

0128321皮特温带河流系统及其相关的洪泛区已大大改变了人类活动。 虽然水坝对河流水文和下游生态系统的影响已经得到了广泛的研究，但关于历史沉积状况和地貌变化如何影响洪泛区生态系统的数据几乎不存在。 本研究将展示一个完整的模型河流系统（北卡罗来纳州的罗阿诺克河）的程度后殖民时代的规模生态系统的改变，由于沉积物的沉积，以及未来的变化可能会影响植被动态，因为这些沉积物被重新分配和运输出系统。 我们将检验一系列具体的假设，这些假设主要集中在以下几个方面：（1）在过去的250年里，罗阿诺克河漫滩上的人为沉积物沉积导致地貌系统内地貌的范围和分布发生了巨大的变化;（2）由于环境变化，下罗阿诺克洪泛区的植被发生了实质性变化，这是由于自2000年以来的地貌变化造成的。群体沉积;（3）根据地貌和古生态数据建立的泥沙影响河岸区模型可用于预测未来的地貌和植被组成。 为了解决这些假设，我们将集成dendrogeomorphic，孢粉学和建模技术（1）开发一个空间上明确的模型后殖民沉积物积累较低的罗阿诺克河洪泛区，（2）模拟前殖民地貌景观和模拟未来的洪泛区地貌，（3）预测植被分布的表面使用植被环境关系。

0128321 PeetTemperate river systems and their associated floodplains have been substantially altered by human activity. Although the effects of dams on river hydrology and downstream ecosystems have been studied extensively, data on how changes in historic sedimentation regimes and geomorphology affect floodplain ecosystems is practically nonexistent. This research will demonstrate for an entire model river system (the Roanoke River of North Carolina) the degree of post-colonial landscape-scale ecosystem alteration due to sediment deposition, and the future changes likely to affect vegetation dynamics as those sediments are redistributed and transported out of the system. We will test a series of specific hypotheses centered on the following: (1) Anthropogenic sediment deposition on the Roanoke River floodplain over the last 250 years has led to a dramatic alteration of the extent and distribution of landforms within the geomorphologic system; (2) The vegetation of the lower Roanoke floodplain has been substantially altered as a consequence of environmental changes due to geomorphic alterations from post-colonial sedimentation; (3) Models of sediment-impacted riparian areas developed from geomorphologic and paleoecological data can be used to predict future landforms and vegetation composition. To address these hypotheses we will integrate dendrogeomorphic, palynological and modeling techniques to (1) develop a spatially explicit model of post-colonial sediment accumulation for the lower Roanoke River floodplain, (2) model the pre-colonial geomorphic landscape and simulate future floodplain geomorphology, and (3) predict vegetation distributions for those surfaces using vegetation-environment relationships.