30 • Wetlands: Their Use and Regulation 



Inland Saline Marshes 



Inland saline wetlands occur primarily in shallow 

 lake basins in the Western United States. They are 

 usually saturated during the growing season and 

 often covered with as much as 2 or 3 feet of water. 

 Vegetation is mainly alkali or hard-stemmed bul- 

 rushes, often with widgeon grass or sago pondweed 

 in more open areas (13). 



Bogs 



Bogs occur mosdy in shallow lake basins, on flat 

 uplands, and along sluggish streams. The soil, often 

 consisting of thick peat deposits, usually is saturated 

 and supports a spongy covering of mosses. Woody 

 or herbaceous vegetation, or both, also may grow 

 in bogs. In the North, leather-leaf, Labrador tea, 

 cranberries, and cotton grass often are present. 

 Cyrilla, persea, gordonia, sweetbay, pond pine, 

 Virginia chain fern, and pitcher plants grow in 

 southern bogs, which are found on the Southeast- 

 ern Coastal Plain. These bogs are more common- 

 ly known as "pocosins" (13). 



Tundra 



Tundra is essentially a wet arctic grassland 

 dominated by lichens (reindeer moss), sphagnum 

 mosses, grasses, sedges, and dwarf woody plants. 

 It is characterized by a thick, spongy mat of living 

 and undecayed vegetation that often is saturated 

 with water. Its deeper soil layer or permafrost re- 

 mains frozen throughout the year; the surface of 

 the tundra is dotted with ponds when not complete- 

 ly frozen. In Alaska, wet tundra occurs at lower 

 elevation, often in conjunction with standing water; 

 moist tundra occurs on slightly higher ground. An 

 alpine tundra or meadow, similar to the arctic 

 tundra, occurs in high mountains of the temperate 

 zone (10). 



Shrub Swamp 



Shrub swamps occur mostly along sluggish 

 streams and occasionally on flood plains (13). The 

 soil usually is saturated during the growing season 

 and often is covered with as much as 6 inches of 

 water. Vegetation includes alder, willows, button 

 bush, dogwoods, and swamp privet. 



Wooded Swamps 



Wooded swamps occur mostly along sluggish 

 streams, on flood plains, on flat uplands, and in 

 very shallow lake basins. The soil is saturated at 

 least to within a few inches of its surface during the 

 growing season and often is covered with as much 

 as 1 or 2 feet of water. In the North, trees include 

 tamarack, white cedar, black spruce, balsam, red 

 maple, and black ash. In the South, water oak, 

 overcup oak, tupelo gum, swamp black gum, and 

 cypress are dominant. In the Northwest, western 

 hemlock, red alder, and willows are common. 

 Northern evergreen swamps usually have a thick 

 ground covering of mosses. Deciduous swamps fre- 

 quently support beds of duckweeds, smartweeds, 

 and other herbs (13). 



Bottom Lands and Other 

 Riparian Habitats 



Riparian habitats, those areas adjacent to rivers 

 and streams, are most commonly recognized as bot- 

 tom land hardwood and flood plain forests in the 

 Eastern and Central United States and as stream- 

 bank vegetation in the arid West. Riparian ecosys- 

 tems are unique, owing to their high species diver- 

 sity, high species densities, and high productivity 

 relative to adjacent areas (1). 



Bottom lands occur throughout the riverine flood 

 plains of the Southeastern United States, where 

 over 100 woody species occur. Bottom lands vary 

 from being permanently saturated or inundated 

 throughout the growing season at the river's edge 

 to being inundated for short periods at a frequen- 

 cy of only 1 to 10 years per 100 years at the uplands 

 edge (7). On the lowest sites that are flooded the 

 longest, most frequently, and to the greatest depths, 

 bald cypress, tupelo gum, button bush, water elm, 

 and swamp privet are most abundant. As eleva- 

 tion increases (and flooding frequency and depth 

 decrease), overcup oak, red maple, water locust, 

 and bitter pecan occur. Nuttall oak, pin oak, sweet 

 gum, and willow oak appear where flooding occurs 

 regularly during the dormant season but where 

 water rarely is present at midsummer. Sites nearest 

 the high-water mark, which are flooded only occa- 

 sionally, have shagbark hickory, swamp chestnut 

 oak, and post oak (4). 



