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

城镇温度河流系统及其相关的泛滥平原因人类活动而发生了重大变化。尽管大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，但关于历史沉积制度和地貌的变化如何影响泛滥平原生态系统的数据几乎不存在。这项研究将为一个完整的模型河流系统(北卡罗来纳州的罗阿诺克河)演示由于沉积物沉积而导致的后殖民景观规模生态系统变化的程度，以及随着这些沉积物被重新分配和输送到系统之外，未来可能影响植被动态的变化。我们将检验一系列围绕以下内容的具体假设：(1)过去250年来，罗阿诺克河泛滥平原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戏剧性的变化；(2)由于殖民后沉积引起的地貌变化，罗阿诺克下游泛滥平原的植被发生了实质性变化；(3)根据地貌和古生态数据发展起来的受泥沙影响的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，我们将结合树状地貌学、孢粉学和建模技术来(1)建立罗阿诺克河下游泛滥平原殖民后泥沙堆积的空间显式模型，(2)模拟殖民前地貌景观并模拟未来的泛滥平原地貌，以及(3)利用植被-环境关系预测这些表面的植被分布。

0105929TownsendTemperate 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.