22A • Technologies To Maintain Biological Diversity 



cies. Wildlife, for example, has been defined 

 in a number of ways, including the following: 



• mammals that are hunted or trapped 

 (game); 



• all mammals — the word animal is some- 

 times used interchangeably with mammal; 



• all animals, both vertebrates and inver- 

 tebrates, excluding fish; and 



• all animals, both vertebrates and inver- 

 tebrates, including fish (65). 



These definitional differences are further evi- 

 dence of the lack of a comprehensive Federal 

 approach to these issues. 



ONSITE BIOLOGICAL DIVERSITY MAINTENANCE PROGRAMS 



U.S. onsite programs seem to have one of 

 three main objectives: 1) maintenance of diverse 

 habitats or ecosystems, 2) preservation of indi- 

 vidual species through habitats' protection, and 

 3) restoration of habitats to their natural con- 

 dition. These objectives are not necessarily ex- 

 clusive. Safeguarding communities and ecosys- 

 tems could help protect rare species. Protecting 

 the habitat of a species may conserve an eco- 

 system or community. And restoring habitats 

 could enhance the diversity of species within 

 an ecosystem. 



Ecosystem Diversity Maintenance 



Maintaining ecosystems is the only way to 

 ensure the continued viability and evolution- 

 ary processes of the organisms within these 

 areas (see ch. 5). Numerous mechanisms exist 

 at the Federal, State, and local level to manage 

 land and water areas for their maintenance. The 

 net result is the continued existence of a diver- 

 sity of ecosystems in the United States. 



Ecosystem diversity maintenance within Fed- 

 eral, State, and private holdings depends on the 

 degree of protection given to the area, its size, 

 and the impact of external influences. Protec- 

 tion of ecosystem diversity within land and 

 water designations ranges from scant to strict. 

 The use of land and waters in the National 

 Wilderness Preservation System is greatly re- 

 stricted — generally, motorized vehicles and 

 long-term human activities are prohibited. 

 Some wilderness areas are regularly patrolled 

 and violators cited. Others receive little regu- 

 latory attention. At the other extreme, estua- 

 rine sanctuaries are not required to have any 



Federal protection; jurisdiction over any use 

 is determined exclusively by the States. One 

 preliminary assessment concluded that pri- 

 vately owned, legally secured, single-purpose 

 nature reserves offer the greatest protection to 

 biological diversity (10). 



The size of a designated area and proximity 

 to other land designations also influence its con- 

 tribution to onsite diversity (10). Some Research 

 Natural Areas (RNAs), for example, are well- 

 protected but may be very small (the smallest 

 is only 2 acres). Numerous vertebrates and 

 larger plants would not be able to survive and 

 reproduce successfully in a small "island" hab- 

 itat; therefore, small RNAs contribute little to 

 community diversity maintenance. 



Natural areas are influenced by human activ- 

 ities on surrounding land that reduce the area's 

 ability to sustain natural biological communi- 

 ties. The National Park Service has reported 

 that 55 percent of the threats to park natural 

 resources come from influences outside park 

 boundaries (64). The National Wildlife Refuge 

 System also noted that influences from adja- 

 cent areas were harming the fish and wildlife 

 within refuges (63). Concern over such threats 

 has prompted introduction of legislation to min- 

 imize negative effects of activities conducted 

 in adjacent areas. 



Table 9-2 provides a summary of the Federal 

 ecosystem conservation programs in which 

 designated areas are maintained in a relatively 

 natural condition. The land designations in- 

 cluded are only some of more than 100 catego- 

 ries used by Federal agencies. Some programs 

 involve more than one agency, such as the Re- 



