Chapter 4 



Interventions To Maintain 

 Biological Diversity 



HIGHLIGHTS 



Four management systems are used to conserve diversity: 1) managing ecosys- 

 tems, 2) managing populations and species in natural or seminatural habitats, 

 3) maintaining and propagating living organisms offsite as in zoos or botanic 

 gardens, and 4) storing seeds or other germplasm, usually with refrigeration 

 or freezing. 



The four systems for maintaining diversity are complementary, but linkages 

 between the strategies (e.g., between zoos and nature reserves) are less well 

 developed than they could be to maximize conservation efforts. 



Biological, political, and socioeconomic factors must be evaluated to choose 

 the best mix of management interventions. Because the importance of main- 

 taining diversity has only recently begun to attract widespread recognition, 

 scientific methods for evaluating trade-offs are at an early stage of develop- 

 ment. Methods for evaluating socioeconomic factors seem to lag behind devel- 

 opment of biological methods. 



The majority of plants, animals, and microbes 

 survive without any specific human interven- 

 tions to maintain them. However, as natural 

 areas continue to be modified— through frag- 

 mentation of habitats, for example— their survival 

 and, in turn, maintaining biological diversity 



will increasingly depend on active manage- 

 ment. A spectrum of technologies— broadly de- 

 fined to include management systems and other 

 means by which knowledge is applied — can be 

 used to maintain diversity. 



MANAGEMENT SYSTEMS TO CONSERVE DIVERSITY 



Two general approaches are followed in 

 maintaining diversity: 1) onsite maintenance, 

 which conserves the organism in its natural set- 

 ting; and 2) offsite maintenance, which con- 

 serves it outside its natural setting. Onsite main- 

 tenance can focus either on an entire ecosystem 

 or on a particular species or population. And 

 offsite maintenance can focus on living collec- 

 tions or on stored germplasm. These four broad 

 management systems are necessary components 

 of an overall strategy to conserve diversity. Con- 

 servation objectives can be enhanced by any 

 combination of the four systems and by im- 



proving the linkages between them to take advan- 

 tage of their potential complementariness. 



Table 4-1 lists some technology programs 

 associated with each management system. In 

 general, the technologies on the right side of 

 the table entail more human intervention. 



Onsite Ecosystem Maintenance 



Where the conservation objective is to main- 

 tain as much biological diversity as possible, 

 the only practical and cost-effective approach 



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