HYPORHEIC ZONE DEVELOPMENT AND WATER QUALITY IMPROVEMENT IN A RESTORED RIPARIAN AREA

摘要

Together with their associated riparian areas, healthy stream systems provide services such as, water supply and storage, aquatic and terrestrial wildlife habitat, and nutrient transport and retention. Research has identified the hyporheic zone as an important part of stream ecosystems. The hyporheic zone is the saturated subsurface sediment that lies directly beneath and beside streams where groundwater and surface water mix. Hyporheic linkages between riparian zones and stream channels greatly influence the translocation of dissolved nutrients and carbon that are fundamental to sustaining stream food webs. As such, hyporheic linkages are a key component to understanding the structure and function of riparian and stream systems in restoration projects. The degradation of stream systems has been widespread throughout the United States. In Kentucky, most of the large streams have been impounded or channelized. In 2003, Bernheim Arboretum and Research Forest (Clermont, KY) implemented a large-scale stream restoration project in a channelized section of Wilson Creek to return the meandering configuration of the stream to its watershed. Restoration activities aimed to reestablish a native riparian corridor using giant cane (Arundinaria gigantea), a historic feature of central Kentucky floodplain terraces, and bottomland forest species such as, American sycamore (Plantanus occidentalis), green ash (Fraxinus pennsylvanica var. Subintegerrima), and pin oak (Quercus palustris). The objectives of this study were to develop techniques for the successful restoration of riparian vegetation communities, and to evaluate the rate at which an active hyporheic zone develops.