US Forested Wetlands: 1940-1980

orested wetlands, like most ecosystems, are undergoing changes in area and composition. Like grasslands and upland forests, many forested wetlands are being converted to farmlands; urban expansion has converted others to suburbs, and still others are now industrial parks or managed recreational areas. Concern for forested wetlands and recognition of their importance has resulted in regulation or protection by various state and federal laws. Among the public resources and benefits involved are wildlife and wildlife habitat, preservation of rare species and species diversity, ground and surface water quality, flood water retention, commercial forest products, and recreation (Brinson et al. 1981, Mitsch and Gosselink 1986). The primary purpose of this article is to assess the magnitude of these changes by summarizing the US Forest Service (USFS) field-data surveys from 1940 to 1980. These data represent the most complete, continuous, and replicable US forested wetland surveys and, as such, can serve as a basis for observing future changes in this important public resource. Our secondary purpose is to use these surveys of today's wetlands in delib-