The majority of species associated with forest environments was composed of 

 terrestrial vertebrates; slightly more plants than animals were associated with range- 

 land systems, and invertebrate species were commonly associated with aquatic 

 environments. 



Reasons Contributing to Species Endangerment 



Without question, habitat loss associated with agricultural development, mining, 

 urbanization, and other intensified human-induced land uses was the single 

 most important reason contributing to species endangerment in the United 

 States (fig.32). 



Figure 32 — Habitat loss associated with human-induced land-use intensifications, such as clearing land for 

 urban development, is the single most important reason contributing to species endangerment in the 

 United States. 



The second most frequent reason for species endangerment was human overuse 

 associated with the harvest or collection of species. Other reasons included disease 

 and predation, impact of nonnative species, grazing, siltation, and environmental 

 contaminants/pollution. 



Effects of Land Ownership Patterns on Listed Species 



Federal lands support a large number of threatened and endangered species. Of 

 the 660 species included in the study, lands managed by the Department of 

 Defense, Forest Service, and the BLM supported 26, 24, and 17 percent of the 

 species, respectively. 



58 



