Contents 



Page 



Chapter Summary 25 



Origins of Wetlands 25 



Glaciation 25 



Erosion and Sedimentation 25 



Beaver Dams 26 



Freezing and Thawing 26 



Activities of Man 27 



Miscellaneous Processes 27 



Hydrologic Characteristics of Wetlands 28 



Wetland Vegetation 28 



Major Types of Wetlands and Closely Related Habitats 29 



Inland Freshwater Marshes 29 



Inland Saline Marshes 30 



Bogs 30 



Tundra 30 



Shrub Swamp 30 



Wooded Swamps 30 



Bottom Lands and Other Riparian Habitats 30 



Coastal Salt Marshes 31 



Mangrove Swamps 31 



Tidal Freshwater Marshes 32 



Geographic Distribution of Wetland Types 32 



Chapter 2 References 33 



TABLE 



Table No. Page 



3. Locations of Various Wetland Types in the United States 32 



FIGURES 



Figure No. Page 



1 . General Distribution of Wetlands of the United States 26 



2. Cross-Sectional Diagram of New England-Type Salt Marsh 29 



3. Physical Subdivisions 33 



