Classification of natural ponds and lakes in the glaciated prairie region

The wetland classification system for the United States adopted by the Bureau of Sport Fisheries and Wildlife in 1953 is described by Martin et al (1953) and by Shaw and Fredine (1956).  That classification has been followed by many biologists in recent years and is especially useful in categorizing in a general manner the wetlands throughout the country over a span of years.  It has become apparent, however, that for research and intensive management a dynamic classification system that more precisely reflects seasonal, regional, and local variations in the environment is needed.  To establish a detailed wetland classification system for all of  North America will require intensive ecological investigation of wetlands in each of the major biogeographical regions.