Compensatory mitigation for wetland loss was established in the United States to help achieve a national goal of no-net-loss of wetlands (Marsh et al. 1996). The effectiveness of this policy has come under scrutiny because of significant failure rates of projects and the difficulty of assessing long-term success within the 3-5 year post-restoration window that is set by most regulatory agencies (Mitsch and Wilson 1996, Zedler 1996, Whigham 1999, Brown and Veneman 2001, National Resource Council 2001). Assessing the success of wetland restoration projects requires an evaluation of ecosystem structure and function. Researchers primarily have assessed restoration success using hydrology and vegetation, with the assumption that functional success will occur if structural components are successfully restored. Long-term success is rarely documented, and failure is common for a variety of reasons. Our overall goal is to continue to evaluate the ecological success of the Tulula Wetlands Mitigation Bank in response to restored hydrology, soils, and vegetation. Our data will provide NCDOT an ecological assessment that will be useful for evaluating other wetland restoration projects throughout the state.
The following objectives provide the framework for a comprehensive ecological assessment of the restored wetlands of Tulula: 1) determine the success of stream realignment by evaluating the geomorphology of the restored channel, 2) evaluate changes in ecosystem structure and function (including soil processes) associated with plant community succession in planted and unplanted portions of the floodplain in response to a higher water table and overbank flooding, and 3) evaluate wildlife use of the site in response to changing hydrologic conditions (amphibians) and plant community succession (birds).
Significant progress was made on restoration at Tulula in 2001 and 2002. Water is now flowing in the restored stream channel. The golf ponds built for the abandoned golf course were partially refilled, and the floodplain was re-contoured in the constructed channel/golf pond areas to enhance heterogeneity in topography (thereby increasing the heterogeneity of wetlands). Tree saplings were planted in the re-contoured floodplain. UNCA has established a variety of ecological studies in the restored portions of Tulula, and data from these studies will be combined with other studies to determine how the site responds to restoration.
UNCA has established long-term monitoring sites throughout the Tulula Wetlands Mitigation Bank. We have ecological data that spans almost ten years and which will provide an excellent framework for evaluating restoration efforts. The ecological research done by UNCA has significantly influenced restoration strategies for the site. Our continuing efforts will provide NCDOT with the most comprehensive database on wetlands restoration in North Carolina. Past CTE and NCDOT funding for this project have allowed UNCA to provide research opportunities for over 60 undergraduate students.
We have outlined projects in this proposal that continue past research efforts as well as initiate new efforts to expand our assessment of restored wetlands at Tulula. The proposed projects will contribute to the long-term analysis of site ecology, and provide information that will guide NCDOT and other government agencies involved with wetland mitigation projects throughout North Carolina.
