Evaluating Restored Tidal Freshwater Wetlands

Tidal freshwater wetlands are recognized as highly productive coastal wetlands that support diverse assemblages of plants and animals and complex biogeochemical cycles (in this book, see Chapter 18 by Whigham et al. and Chapter 19 by Megonigal and Neubauer). Many tidal freshwater wetlands and their associated ecosystem services have been damaged or destroyed by urbanization, agriculture, and other human activities (Baldwin, 2004; Barendregt et al., 2006). Increasing recognition of the value of remaining wetlands and environmental regulations requiring wetland mitigation (i.e., enhancement, creation, or restoration of wetlands to compensate for wetland losses; Kentula, 2000) has driven the restoration of all types of wetlands, including tidal freshwater wetlands. These restoration projects have been increasingly studied by restoration ecologists, with the overarching goal of improving restoration approaches. In this chapter, we first review characteristics of restored tidal freshwater wetlands in North America and Eurasia, where most studies have been done, including their distribution, general construction methods, and motivating factors for restoration (Section 2). Then we present criteria for evaluating tidal freshwater wetland restoration projects (Section 3). Next we describe a case study of restored tidal freshwater wetlands in the Anacostia River watershed in Washington, DC, USA (Section 4). Finally, we provide conclusions and recommendations to increase the successful restoration of tidal freshwater wetlands (Section 5)