I 



$160 land value. These waterfowl values were then 

 compared with 1984 and 1985 land values of 

 agricultural lands in 20 Mississippi Flyway counties 

 that had been at least 75-percent drained. The net 

 agricultural value (gross land value minus estimated 

 conversion cost) averaged $628 per acre in 1984. 

 The land value from waterfowl hunting ranged 

 from 21 to 63 percent of the agricultural value, 

 with an average of 30 percent. However, because of 

 the decline in land values in 1985 the average in- 

 creased to 43 percent for 1985, and ranged from 24 

 to 93 percent of agricultural value. This indicates 

 that the value of wetlands for hunting can be com- 

 petitive with agricultural values, particularly if the 

 value for hunting increases over time. 



Some values cited in this section are summarized 

 in table 13 on a per acre basis to approximate 

 annual income streams. The values are shown in 

 1984 dollars, ranging from $3.04 to $10,333 per 

 acre. The highest values are for ecological func- 

 tions. These values are among the most difficult to 

 estimate, and must be viewed with caution. 



Presenting these values on a per acre basis is 

 artificial in the sense that the economic values of 

 wetland are not divisible. For example, a 50-percent 

 reduction in wetland area does not imply a simple 

 50-percent reduction in benefits. Wetlands must be 

 treated as ecological units that have a minimum 

 size below which they can no longer provide cer- 

 tain values. The estimation work done to date has 



Table 13— Estimated wetland values per acre, 

 from recent studies 



Sources: (4, 9) 



provided valuable information about wetland 

 values. However, these estimates are site-specific 

 for the most part and not amenable to generaliza- 

 tion. Further research on the role of wetlands 

 throughout the country is needed for consistent 

 estimation. If, in fact, these functions provide such 

 large benefits there is a tremendous incentive to 

 preserve wetland ecosystems. 



Critical Wildlife Wetland Areas 



Tiner (43) identified nine wetland areas in the con- 

 tinental United States where vdldlife are most 

 threatened by conversion. They are: 1) estuarine 

 wetlands of the coastal zone, 2) Louisiana's coastal 

 marshes, 3) Chesapeake Bay's submerged aquatic 

 beds, 4) South Florida's palustrine wetlands, 5) 

 prairie pothole emergent wetlands, 6) Nebraska's 

 Sandhills and Rainwater basin, 7) forested wetlands 

 of the Lower Mississippi alluvial plain, 8) North 

 Carolina's pocosins, and 9) western riparian 

 wetlands. Agricultural conversion is considered a 

 major threat to wetlands in six areas (4 through 9). 

 Although conversion is not a primary threat in the 

 other three areas, agricultural nonpoint pollution is 

 damaging wetlands in those areas. 



According to the 1982 NRI, 813,000 acres of non- 

 Federal wetlands have a high potential for 

 agricultural conversion, while another 4.4 million 

 acres have medium potential. Using the 1982 NRI 

 data, we matched Tiner's six problem areas as 

 closely as possible with major land resource areas 

 (MLRA's), in order to determine how much wetland 

 with high and medium conversion potential fell 

 into those six areas (fig. 6). In table 14, the six 

 problem areas are listed with the number of acres 

 in each that have high, medium, or unlikely poten- 

 tial as cropland. Thirty percent of all non-Federal 

 wetlands fell into these six areas, including 37 per- 

 cent of acres with high conversion potential and 34 

 percent with medium conversion potential. Hence, 

 wetlands with high and medium potential for 

 cropland are not concentrated in these six areas. 

 Other wetland areas may have higher concentra- 

 tions of high and medium potential cropland and 

 should be examined for threatened wetland values. 



South Florida's Palustrine Wetlands 



These wetlands cover a 9,000-square-mile area that 

 includes the Everglades. Freshwater runoff from 

 this area is essential to maintain the salinity 

 balance of coastal estuaries, which support 85 per- 

 cent of Florida's offshore fishery. Also, southern 

 Florida is a breeding ground and a wintering 



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