to decreased reproduction and increased likelihood 

 of disease {43). Although the Federal Government 

 has an acquisition and easement program in the 

 area, approximately 90 percent of the wetlands are 

 privately owned {27). 



There are 93 million acres in the 10 MLRA's used 

 to approximate the pothole region, including North 

 Dakota, South Dakota, Minnesota, and parts of 

 Montana and Iowa. The predominant use was 

 cropland, which covered 63 million acres. There 

 were 4.9 million acres of non-Federal wetlands in 

 the 10 areas. Only 62,000 acres had high potential 

 for conversion, but 2.5 million acres had medium 

 conversion potential. 



Nebraska's Sandhills and Rainwater Basin 



These two areas in Nebraska are a critical 

 migratory stopover for waterfowl in the central 

 flyway and for sandhill cranes. Eighty percent of 

 the Nation's sandhill cranes use the Sandhill region 

 of the Platte and North Platte Rivers during spring 

 migration, and the endangered whooping crane also 

 migrates through the area. The Rainwater basin is a 

 spring stopping ground for approximately 2.5 

 million ducks and geese. Drainage for agricultural 

 production, filling for pivot irrigation, and lowered 

 groundwater levels from irrigation pumping all 

 have affected wetlands in this area. Upstream diver- 

 sions of the Platte River have changed the vegeta- 

 tion of the area and reduced the number of suitable 

 roosting areas for sandhill cranes. The remaining 

 roosting sites are more crowded, which increases 

 the chance of disaster from weather or disease. 

 There have already been outbreaks of avian cholera 

 in the Rainwater basin area because of the water- 

 fowl crowding on remaining wetlands (43). An 

 estimated 1 million acres of wetland remain in the 

 Sandhills, while only 14,000 to 24,000 acres remain 

 in the Rainwater basin (15). 



Three MLRA's totaling 26.5 million acres were 

 used to approximate the Sandhill and Rainwater 

 basin areas. Although 9.5 million acres were 

 cropped in 1982, the predominant use was 

 rangeland. Only 859,000 acres of non-Federal 

 wetlands are found in the three areas; of that, 

 26,000 had high potential for conversion and 

 105,000 had medium potential. 



Forested Wetlands of the Lower Mississippi 

 Alluvial Plain 



The wetlands of the Lower Mississippi are prime 

 overwintering habitat for waterfowl, and provide 



fish spawning and nursery grounds, flood storage, 

 and water quality maintenance. About 80 percent of 

 the original 24 million acres of wetlands are gone, 

 leaving about 5.2 million acres. Agricultural conver- (^ 

 sion has been the predominant cause of conversion, 

 with Federal flood control and small watershed pro- 

 grams accelerating cropland conversion. Conver- 

 sion threatens wildlife populations and also in- 

 creases the frequency of damaging floods {43). 



Two MLRA's were used to approximate the area, 

 with a total acreage of 41 million acres. More than 

 one-half (22 million acres) was in cropland in 1982, 

 with the remainder largely in forest. Non-Federal 

 wetlands in the two areas covered more than 4 

 million acres. Only 96,000 acres (2.4 percent) had 

 high potential for conversion, while 302,000 had 

 medium potential. 



North Carolina's Pocosins 



Conversion of North Carolina's pocosin wetlands 

 through farming and forestry is a serious threat in 

 the coastal plain. About 70 percent of the Nation's 

 pocosins occur in North Carolina. They provide 

 habitats for a variety of species, stabilize water 

 quality, and balance salinity in coastal waters. Ap- 

 proximately 1 million acres of pocosins remain. 

 Major timber companies own about 44 percent of 

 the State's pocosins, but large tracts are being T 



transferred to agricultural corporations. Conversion 

 of pocosins is generally limited to large-scale 

 agriculture because of the large investments re- 

 quired. The converted land creates runoff problems 

 for adjacent estuaries. A more recent threat to the 

 pocosins is peat mining {43). 



It was not possible to isolate the North Carolina 

 pocosins by MLRA. Therefore, we used coastal 

 wetlands in two MLRA's that encompass the North 

 Carolina pocosins as well as wetlands in South 

 Carolina and Georgia, not all of which are 

 pocosins. These two MLRA's cover almost 25 

 million acres in the three States. Only 4.7 million 

 acres were in crops at the time of the 1982 inven- 

 tory, with a majority still in forest. A total of 7.7 

 million acres of non-Federal wetlands were in these 

 two areas, with 18,000 acres having high potential 

 for conversion and 271,000 acres having medium 

 potential. 



Western Riparian Wetlands 



Riparian wetlands are lands along the floodplains 

 and the margins of ponds and lakes in arid and 

 semiarid regions. These narrow strips of vegetation (^ 



22 



