BIODIVERSITY

Biodiversity is the diversity of different species together with genetic variation within each species in a given area. United Nations Environment Programme (UNEP) defines it as the totality of genes, species and ecosystems in a region. In simple words biodiversity is the variety of genes, species and ecosystem in a given region at a given time.

Based on the elements of biodiversity it is divided into the following types:

(1)    Genetic Diversity – Genetic diversity of genes within species or population e.g. different varieties of rice. It is basically the diversity of genes which determines the diversity of species which in turn determines diversity of a population and ecosystem. More genetic diversity within a species means greater variability and adaptability of individuals of species to environmental changes. Lesser genetic diversity leads to susceptibility to environmental changes and threat of elimination.

Genetic diversity on a larger scale is sometimes equated with Gene Pool. A gene pool is the total genetic diversity found within a population or species. A large gene pool has extensive genetic diversity and is better able to withstand the environmental stresses. In –breeding contributes to the creation of small gene pool and makes populations or species more likely to go extinct when faced with some stress.

(2)    Species Diversity:

Species biodiversity means variety of species of biological communities such as plants, animals, microbes etc. of a given ecosystem. For example in a tropical rainforest or savanna or monsoon forest, we find at least 100 species of animals but in a temperate forest there will be less number of species say only 40 due to environmental conditions. The greater the diversity of species, greater is the length and complexity of food chain and food web. This in turn leads to further development of ecosystem and evolution of newer and diverse species. Because of this richness of the species diversity the tropical rainforest became hotspots of biodiversity.

(3)    Ecosystem Diversity: The diversity of ecosystems is determined by the divert of biophysical processes. Variety of habitats and niches for biological communities, etc, which in turn determines the diversity f species. The diversity of ecosystem is determined by weather including rainfall, temperature, topography, soil, etc. physical factors.