1 Levels of Biodiversity
1) Genetic diversity
v It is a level of biodiversity that refers to the total number of genetic characteristics in the genetic makeup of a species.
v It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary.
2) Species diversity
v It refers to the variety of species within a region.
v Species diversity is an index that incorporates the number of species in an area and also their relative abundance.
v It is generally a much more useful value than species richness.
3) Community and Ecosystem diversity
v Ecosystem diversity refers to the diversity of a place at the level of ecosystems. This has 3 perspective:
v Alpha Diversity: Within community diversity. Alpha diversity refers to the diversity of organisms sharing the same Community/Habitat.
v Beta Diversity: Between community diversity. It refers to the diversity of organisms sharing two habitats.
v Gamma Diversity: Diversity of the habitat over the total landscape or geographical area is called gamma diversity.
2 Values of Biodiversity
Food: About 80,000 edible plants and about 90% of present day food crops have been domesticated from wild.
Drugs & Medicines: About 75% of world’s population depends on plants or plant extracts.
Fuel: Forests have been used since ages for fuel wood. Fossil fuels are also products of Biodiversity.
Social Value: Many of the plants like Tulsi, Lotus, Peepal etc are considered holy and sacred.
v About 2.1 million species have been identified till date, while many more species are believed to exist.
v According to UNEP estimate, approximately 9.0 – 52 million of species exist on Earth
v India’s position is 10th in the world & 4th in Asia in terms of Plant diversity.