A certain degree of biodiversity occurs within all habitats because genetic diversity has allowed life to adopt to varying conditions of environment. However, species are not evenly distributed over the earth’s surface. Biodiversity is greater in some areas than others. Habitats like tropical forests possess greater number of species or the density of species than others.

Therefore, it becomes important to identify important centres of biological diversity before undertaking any conservation project. Which areas should be given priority? Which are the areas which require immediate conservation efforts? An obvious answer to these questions is that we must choose those areas for immediate conservation efforts which possess the richest and the most diverse plant and animal communities under some kind of threat from internal or external sources. Identification of important areas to direct the conservation efforts can be achieved at national or global levels by following methods:

1. Observations on Over-all Species Diversity:

The simplest method of targeting areas for conservation is to select countries which possess the largest number of species – countries with greatest species richness. A very small number of countries occurring in tropical climate possess the largest proportion of world’s species diversity.

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These countries are referred to as ‘Mega-diversity Countries (Mittermeier 1988, Mittermeier and Werner 1990). It has been suggested that these countries should receive special international biodiversity conservation attention. Mc Neely et al. (1990) have used the lists of vertebrates, swallow tail butterflies and higher plants of different countries to identify twelve such mega-diversity countries which together possess the largest number of species (nearly 70% of all) in a relatively small area.

This approach is relatively simple as it needs only lists of species which occur within a geo­political zone and emphasises that the conservation effort should be managed at country level. However, the approach suffers from the disadvantage that it fails to take into account the uniqueness of the flora and fauna of the region.

By focusing our attention on habitats which possess the greatest number of plant and animal species we may leave out unique and important organisms which happen to occur in regions with a very low diversity. Moreover, there may be considerable degree of overlap – the same species may occur in a number of countries. Thus relatively unimportant, widely distributed species which may not be threatened at all may receive more conservation attention than the species which actually need it.

2. Observations on Endemic Species Diversity:

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An endemic species is that species which is restricted to a given habitat or locality. The fact that an endemic species is confined to a particular location and is not found anywhere else makes it important. Areas with largest number of such species should receive more attention as endemic species once lost from its original abode cannot be obtained from anywhere else.

Based on the degree of endemism in species composition Myers (1988) has identified 12 such localities in tropical regions of the world which require urgent conservation attention. In 1990, he identified another eight hot spots of endemic species diversity in other climatic regions of the world.

Thus, nearly 49,955 endemic species of plants occur in an area barely 786,400 sq. kms or only 0.5% of the world’s total land surface. It is usually observed that a greater degree of endemism in one taxonomic group corresponds with a similar degree of endemism in other taxonomic groups as well.

Thus in practice it is often convenient to make observations on the extent of endemism in one or two taxonomic categories only. Although there ma) be a few exceptions, in majority of cases a greater degree of endemism is met with in those regions of world which have a richer and more diverse flora and fauna. Endemism is, therefore, a very valuable parameter for the identification of areas of greater biological significance.

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3. Critical Faunal Analysis:

The concept of critical faunal analysis was first introduced by Ackery and Vane Wright in 1984. It is now being increasingly used to determine conservation priorities. The entire spectrum of life forms within a group under consideration in a locality is called) ‘compliment’. The portion of forms not included in this compliment is designated as ‘residual compliment’.

After the selection of a compliment which represents the maximum number of endemics the priority for the second site is determined by the residual compliment which adds the largest proportion of life forms to the initial choice. The third site is the site which adds the maximum residual compliment to the second site. In this way the process may be continued in the selection of fourth and fifth site in step wise fashion till the entire biotic spectrum is brought under conservation efforts. The process offers the advantage of providing an objective and optimized sequence of priority for the conservation efforts to be carried out and the performance of any other sequence can be judged for its relative efficiency in representing total biodiversity of the locality.

For example, Serengiti National Park (Tanzania), is one of the earliest site, protecting a population of 24% of the antelope species. Kufu National Park (Zambia), if including, shall bring under conservation efforts the highest number of antelope species. Together these two parks contain 38% of all antelope species. If we add two more reserves, i.e., Haut Dod Faunal Reserve (Cote D’lvoire) and Quadi Reme-Quadi Achim Faunal Reserve the four protected reserves shall represent about 56% of the antelope species diversity. Thus just these four protected habitats can bring under conservation efforts about 56% of all antelope species of Africa.