County-Level Distribution of Listed Species 



Counties that supported many endangered species were grouped according to 

 climate, physiography, soils, vegetation, and land use. This resulted in the identifica- 

 tion of 10 regions of high species endangerment. These regions were concentrated in 

 the Southern United States, with all but the Colorado/Green River Plateaus occurring 

 south of 40 degrees North latitude. 



In general, regions of high species endangerment in the Eastern United States 

 were associated with forest ecosystems, while those regions in the West were 

 associated with rangeland ecosystems. Endangerment regions in the East were 

 associated with intensive human land use activities. In the West, collecting rare 

 plants (Southern Desertic Basins, Plains, and Mountains), surface mining and oil 

 and gas development (Central Desertic Basins), and exotic species and water 

 diversions (Southern Nevada/Sonoran Basin) were the most frequently cited 

 causes for endangerment concern. 



Spatial Distribution of Candidate Species 



Category 1 species include species for which the Fish and Wildlife Service has 

 sufficient biological evidence to support their official listing as threatened or endan- 

 gered. There were 526 of these species in 1989-90. These species were tabulated by 

 State of occurrence so as to gain an understanding of where new listings of species 

 might occur in the future. 



The Southeast and Southwest remain areas where species endangerment will be 

 concentrated. The only new region of species endangerment that may emerge in the 

 future is the Pacific Northwest, including Oregon, Washington, and Idaho. 



Issue Highlight— 

 Analysis of Trends in 

 Non-Federal Wetland 

 Habitats 



Wetlands are among the most productive of ecological systems. Between 1954 and 

 1974, wetland habitats were lost at a rate of 460,000 acres per year. Studies of 

 wetlands since the mid-1 970's suggest that the rate of wetland loss is declining. 

 Continued significant declines in wetland area could affect the outlook for some 

 species of wildlife and fish. We initiated a study with the objective to determine recent 

 trends in non-Federal wetland habitats (Brady and Flather, 1993). 



The study involved analysis of wetland area trends in data from the National Re- 

 sources Inventory for non-Federal lands for the period 1982-87. The trend for this 

 period was compared with estimates of others for earlier periods. 



The National Resources Inventory estimated that there were 83.1 million acres 

 of wetlands in 1982 on non-Federal rural lands in the coterminous United States. 

 Analysis of change between 1982 and 1987 indicates that net wetland area 

 declined 1.1 percent (897,000 acres) during this period. The average annual rate 

 of loss of 179,000 acres is about 40 percent of that reported for the period from 

 the mid-1 950's to the mid-1 970's and about 60 percent of the rate reported for 

 the period from the mid-1 970's to the mid-1 980's. 



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