Dissertation Research: Influence of River Geomorphology on Pathways of Primary Forest Succession

这项研究将检验一个新的概念模型，解释高能河流的河弯迁移如何影响物种丰富度高的河岸森林的初级演替。传统的河岸森林演替模型描述了单一的演替路径，而该模型预测了与河道形状相关的可预测的地貌过程促进的多条演替路径。这项研究的具体目标包括(1)实地试验，以测试海拔、土壤质地、光照、淹没和/或物理洪水破坏在确定树种在新地貌上形成的相对重要性；(2)实地试验，以确定地下水位对几种常见泛滥平原树种的出苗和存活的重要性；以及(3)确定所提出的东南沿海平原河流之间演替模型的普遍性。通过揭示可预测的地貌过程和初级演替途径之间的重要联系，验证所提出的初级演替概念模型将加深我们对森林结构异质性的理解。这一认识将有助于明智地管理东南部河流，以保持自然栖息地的多样性。这项拟议的研究在对影响河岸植被景观规模格局的小规模物理过程的实验调查方面是独一无二的，并将作为未来景观生态学研究的模型。

9902065AugspurgerThis dissertation research will test a new conceptual model explaining how river bend migration of high-energy rivers influences primary succession of riparian forests with high species richness. Whereas the traditional model of riparian forest succession describes a single pathway of succession, the proposed model predicts multiple pathways of succession promoted by predictable geomorphic processes related to the shape of the river channel. Specific objectives of this research include (1) a field experiment to test the relative importance of elevation, soil texture, light, inundation, and/or physical flood damage in determining where tree species become established on new land forms, (2) a field experiment to determine the importance of depth to water table on emergence and survival of several common floodplain tree species, and (3) determining the generality of the proposed model of succession among rivers in the southeastern Coastal Plain. Confirmation of the proposed conceptual model of primary succession will refine our understanding of heterogeneity of forest structure by revealing important links between predictable geomorphic processes and pathways of primary succession. This understanding will contribute to the wise management of southeastern rivers with the purpose of maintaining natural habitat diversity. The proposed research is unique in its experimental investigation of small-scale physical processes that influence landscape-scale patterns of riparian vegetation and will serve as a model for future studies in landscape ecology.