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Salt marsh is an emergent, interdial estuarine wetland system characterized by persistent plant species such as cordgrass ( Spartina alterniflora ). Saltmarsh has a fringe geomorphic setting, and the water source and hydrodynamics are predominantly surface or near surface bidirectional flows. | CHAPTER 1 Definition Classification and U.S. Regulation Donald M. Kent CONTENTS Definition Classification Classification of Wetlands and Deepwater Habitats of the United States A Hydrogeomorphic Classification for Wetlands U.S. Regulation Regulating Agencies Army Corps of Engineers Environmental Protection Agency Fish and Wildlife Service National Resource Conservation Service National Marine Fisheries Service References DEFINITION Wetlands are defined directly or implicitly in a variety of ways. Several factors including personal perspective position in the landscape and wetland diversity and function contribute to the tractable nature of the definition. Each individual or group brings to the definition its own perspective based upon cumulative experience and personal needs Figures 1 to 4 . For example the lay person asked to define wetlands may envision a deep-water marsh teeming with 2001 CRC Press LLC ducks or alternatively a dark swamp. To an engineer a wetland may be a place that will require a specialized construction design to accommodate poorly drained soils. The scientist likely has a functional perspective defining a wetland as a place where anaerobic processes occur and plants are adapted specially for living in saturated or inundated conditions. Finally those charged with regulating wetland use are likely to have a structural perspective defining wetlands by characteristic soil hydrology and plants so as to facilitate permit decision making. Figure 1 Salt marsh is an emergent interdial estuarine wetland system characterized by persistent plant species such as cordgrass Spartina alterniflora . Saltmarsh has a fringe geomorphic setting and the water source and hydrodynamics are predominantly surface or near surface bidirectional flows. Defining wetlands is further complicated by their position in the landscape. Wetlands are transitional habitats in the sense that they are neither terrestrial nor aquatic but exhibit characteristics of both. Their .
