Levels of Biodiversity

Biodiversity or Biological diversity is a term that describes the variety of living beings on earth. In short, it is described as the degree of variation in life. Biological diversity encompasses microorganisms, plants, animals and ecosystems such as coral reefs, forests, rainforests, deserts etc.

What is Biodiversity

There are generally three levels of biodiversity: genetic, species and ecosystem. These levels are all interrelated yet distinct enough that they can be studied as three separate components.

Genetic diversity is the variety of genes within a species. Each species is made up of individuals that have their own particular genetic composition.
This means a species may have different populations, each having different genetic compositions.
For ex. India has more than 50,000 genetically different strains of rice, and 1,000 varieties of mango.

Species diversity is the variety of species within a habitat or a region.
For ex. Some habitats, such as rainforests and coral reefs, have high number of species residing in them.

It is the variety of ecosystems in a given place. An ecosystem is a community of organisms and their physical environment interacting together.
An ecosystem can cover a large area, such as a whole forest, or a small area, such as a pond.
For ex India, with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows has a greater ecosystem diversity than a Scandinavian country like Norway.

The IUCN Red List tracks the number of described species and updates this figure annually based on the latest work of taxonomists. In 2021 it listed 2.13 million species on the planet.
In this pool of recorded species of animals, insect forms majority of share. If we look at the breakdown across a range of taxonomic groups – 1.05 million are insects; over 11,000 are birds; over 11,000 are reptiles; and over 6,000 are mammals.
One important fact that should be kept in mind is the number of fungi species in the world is more than the combined total of the species of fishes , amphibians, reptiles and mammals.

One of the most widely-cited figures comes from Camilo Mora and colleagues; they estimated that there were around 8.7 million species on Earth today.

Although India has only 2.4 per cent of the world’s land area, its share of the global species diversity is an impressive 8.1 per cent. That is what makes our country one of the 12 mega diversity countries of the world.
Nearly 45,000 species of plants and twice as many of animals have been recorded from India.
Along with species richness, India also possesses high rates of endemism.
In terms of endemic vertebrate groups, India’s global ranking is tenth in birds, with 69 species; fifth in reptiles with 156 species; and seventh in amphibians with 110 species.
Endemic-rich Indian fauna is manifested most prominently in Amphibia (61.2%) and Reptilia (47%).
India is also recognized as one of the eight Vavilovian centers of origin and diversity of crop plants, having more than 300 wild ancestors and close relatives of cultivated plants, which are still evolving under natural conditions.