116 * Technologies To Maintain Biological Diversity 



Figure 5-2.— National Conservation Strategy Development Around the World, July 1985 



I Category 1: substantial consensus 

 document produced and endorsed 

 by the government 



I Category 2: substantial consensus 

 document produced but not yet 

 endorsed 



I Category 3: process of preparing 



such a document definitely 

 I happening 



I Category 4: course of action 



initiated that looks likely to lead 

 I to an NCS 



D 



Category 5: other involvement 

 (an NCS at exploratory stage/ 

 strategic planning for resource 

 management at subnational level) 



SOURCE: lUCN Bulletin Supp/emenr (Gland, Switzerland: lUCN, 1985). 



the characteristics of species but greater under- 

 standing of larger cause-and-effect relation- 

 ships and of social, economic, and political 

 factors. 



Management Strategies 



Increasingly active management of factors 

 affecting biological diversity will be needed to 

 overcome the effects of human activity and the 

 gradual fragmentation of natural areas (89). Nat- 

 ural areas change over time, as various plant 

 and animal communities succeed one another, 

 and gradual change in the components and 

 quantity of biological diversity occurs. To sus- 

 tain particular components, such as game ani- 

 mals or songbirds, protected-area managers 

 therefore need to intervene in the natural proc- 

 esses. The interventions vary with objectives, 

 and conflicts may occur. For example, devel- 

 oping optimum habitat for a particular species 

 may not be compatible with maximizing the 

 diversity of community types. 



Manipulating habitats to manage particular 

 species sometimes involves controlling popu- 

 lations of certain animals— removing an exotic 

 fish from a lake, for example. More often, the 

 intervention involves modifying vegetation. If 

 the target species are grazing or browsing ani- 

 mals such as deer, intervention might mean cut- 

 ting trees to prevent woodlands from evolving 

 to the climax stage; for prairie birds such as 

 cranes, it could mean burning grasslands to pre- 

 vent encroachment by woody plants. Certain 

 plants may be propagated for food or cover for 

 the target species. The U.S. Fish and Wildlife 

 Service uses such management techniques in 

 national wildlife refuges, which are the only 

 extensive federally owned lands managed chiefly 

 for conserving wildlife. 



Management to maximize the diversity of 

 community types involves similar interven- 

 tions. Again, a basic consideration is the vari- 

 ety of plant succession stages to be maintained 

 within an ecosystem. Manipulation manage- 

 ment is likely to be needed to preserve com- 



