Comparative Study of a Mitigation Project to Both an Impacted Wetland and a Natural, Untouched Wetland. Kalle Pladl Department of Biological Sciences, York College of Pennsylvania, York, PA Introduction: -The definition of a wetland, adopted by the U.S. Fish and Wildlife Service is “lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water” (Federal Interagency… 1989). -Wetlands are considered one of the most essential ecosystems, functioning in flood prevention, water quality preservation, trapping nutrients and sediments, and providing for the growth and development of organisms that require wetland habitat (Balcombe et al. 2005). -Recognition of their values in the past few decades has translated into protection laws and management plans to preserve these fragile systems. If wetlands are destroyed or impacted for any reason, such as construction, the wetland replacement criterion of the PA Dept. of Environmental Protection states that a minimum area replacement of 1:1 is necessary (Federal Interagency… 1989). -The “no-net-loss” policy made mitigations one of the most important tools to combat wetland loss, but monitoring is sporadic, not enforced, or shows low success rates (Balcombe et al. 2005) Objective/Hypothesis: I conducted this study to re-investigate the success or failure of a local mitigation project at the New Brittany Phase I Residential Subdivision in York, PA. Since the mitigated wetland failed to meet the 1:1 replacement criteria for vegetation coverage, I commented on overall function rather than size, comparing the mitigated wetland to the impacted wetland it replaced (which still functions as such), as well as to a natural, untouched wetland on the same site. Based on visual observation, my hypothesis is that mitigated wetland is more functional than the impacted wetland. Methods: The following methodology was taken from the routine wetland guide in the 1987 COE Manual, adopted by the state of PA (Wetland Training…1991). For each wetland, an initial analysis of common vegetation and typical wetland characteristics was conducted. Sample points were separated at 20ft intervals within transects set up every 50-55ft perpendicular to the water flow. At each sample point, the following measurements were taken: Vegetation: Using a square meter, both the vascular plant vegetation within it was identified and the percent area coverage for each species was estimated. Hydrology: Water coverage was noted, either as no signs of hydrology, saturated to surface or a depth of water in inches was measured with a meter stick. Soil: Using a shovel, a 12-13” hole was dug at each wetland and the color of a moist soil sample taken from each horizon was determined using the Munsell Soil Color Book (2000). Literature Cited Balcombe, C.K., Anderson, J.T., Fortney, R.H., Rentch, J.S., Grafton, W.N., and Kordek, W.S A comparison of plant communities in mitigation and reference wetlands in the mid- Appalachians. Wetlands 25(1): Federal Interagency Committee for Wetland Delineation Federal Manual for Identifying and Delineating Jurisdictional Wetlands. U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, and U.S.D.A. Soil Conservation Service, Washington, D.C. Cooperative technical publication. 76 pp. plus appendices. Munsell Soil Color Charts GretagMacBeth, New Windsor, NY. Munsell Color. Wetland Training Institute, Inc Field Guide for Wetland Delineation: 1987 Corps of Engineers Manual. WTI pp. Acknowledgements: Special thanks to Dr. Bruce Smith of York College of Pennsylvania and Tom Stich of LSC Design for dedicating their time and effort to help me create and complete this project. Discussion: Based on the results obtained, the mitigation functions more as a wetland than the impacted one it replaced, showing greater similiarities to the natural, untouched wetland’s functioning. It has greater richness of wetland-typical vegetation species, and also shows more total water saturation across the site. The mitigation also serves as a more suitable habitat for a number of animals. Although it failed to replace the 0.63 acres of vegetation coverage set forth in the permit, a possible suggestion to fix this problem is to install more plant species so that it meets the percent coverage requirement. Results: The mitigated wetland seemed to serve the most wildlife, with muskrats (Ondatra zibethicus), many geese, and green heron (Butorides virescens). At wetland A I saw three woodcocks (Scolopax sp.), which are all wetland species, but I did not observe any wildlife at wetland B. Mitigated Wetland Wetland B - Impacted Wetland A - Natural