Ch. 5— Maintaining Biological Diversity Onsite • 113 



India and the Soviet Union have expressed 

 commitment to in-situ conservation of the wild 

 relatives of crop species (63). India has desig- 

 nated the first gene sanctuary, for citrus, and 

 some Indian biosphere reserve areas are ex- 

 pected to have genetic conservation as a ma- 

 jor objective. For example, a reserve area has 

 been proposed for the Nilgiri Hills area, which 

 is rich in wild forms of ginger, tumeric, carda- 

 mom, black pepper, mango, jackfruit, plantain, 

 rice, and millets. The Soviet Union has reportly 

 designated 127 reserves for protection of wild 

 relatives of crops and has proposed an addi- 

 tional 20 areas for protection. Expeditions to 

 a region known as the Central Asian gene cen- 

 ter have found 249 species of wild crop rela- 

 tives (63). 



In East Germany, an inventory is being made 

 of important genetic resources within the coun- 

 try's nature reserves, including 24 forage crop 

 species, 51 medicinal plants, and 27 fruit spe- 

 cies. As noted earlier, the inventory is expected 

 to identify about 10,000 places within the coun- 

 try's reserve system where protection is af- 

 forded for plants relevant to breeding, breed- 

 ing research, and study of the chemistry of 

 natural substances (68). 



Trade-Offffs 



In selecting areas for onsite maintenance of 

 biological diversity, trade-offs occur when any 

 of the above criteria are given priority. If the 



strategy is to protect areas where rare and en- 

 dangered species are found, then the diversity 

 of ecosystems that exists may not be maintained 

 adequately because only certain types include 

 identified rare species. Concentrating on bio- 

 geographic categories for broad coverage of 

 ecosystem types may not protect habitats for 

 rare or endangered species sufficiently or for 

 centers of endemism. The third criterion, pro- 

 tecting genetic variability, includes consider- 

 ation of economic and social factors that may 

 contribute less to the objective of maintaining 

 maximum diversity but aid the larger goal of 

 conserving resource opportunities for human 

 welfare. 



In practice, other objectives and various so- 

 cial and economic constraints prevail in the de- 

 cisions on where to locate protected areas. 

 Other objectives include preservation of scenic 

 resources, provision of recreation opportuni- 

 ties, and protection of watersheds. Constraints 

 include budgetary feasibility, competing de- 

 mands for use of the area, and opportunity for 

 local support of protected status. 



The literature on conservation strategies con- 

 tains few objective methods to evaluate these 

 trade-offs, except to note that the three biologi- 

 cal approaches — ecosystem, species, and gene 

 pool— are both complementary and necessary. 

 Decisions are often initially made by the intui- 

 tive judgment of conservationists but ultimately 

 by the political processes that lead to the offi- 

 cial protected area designation. 



PLANNING AND MANAGEMENT 



Planning and management strategies for on- 

 site maintenance seek to conserve either the 

 species and genetic diversity within a given 

 area or the diversity of ecosystems across a geo- 

 graphic region. Planning tools range from 

 mathematical models that simulate how an 

 area's biological resources are likely to respond 

 given different management options to written 

 plans for natural area management. Manage- 

 ment is concerned both with managing exter- 

 nal pressures affecting a protected area and 

 with managing the natural succession of plant 

 and animal communities within the area. Man- 



agement activities range from no intervention 

 to active manipulation of an ecosystem. 



Planning Techniques 



Planning for protected areas can begin be- 

 fore designation is finalized. Biologists gener- 

 ally agree that plans to maintain diversity need 

 to begin with site surveys to determine the fol- 

 lowing information (65): 



• the number, abundance, and distribution 

 of species, and the interactions between 

 species and community types; 



