Concept of Biodiversity

Biodiversity means biological diversity.  The term biodiversity was coined by Walter G Rosen in 1985.  Biodiversity is an “umbrella term” used to refer to the number, variety   and variability of living organisms found within the living world.  The International Union for Conservation of Nature (IUCN) defines biodiversity as “the diversity of life on earth including the number, variety and variability of living organisms like animals, plants, microbes etc. and the genetic difference among them and the ecosystem in which they occur”. In simple terms, we can say, biodiversity is the variation in species, genes and ecosystem within an area, biome or planet. 

Biodiversity is the result of billions of years of evolution. Biodiversity is a very vast and complex concept and is generally treated under three fundamental hierarchical levels. Yucel in 2015 divided biodiversity into three main components namely species diversity, genetic diversity and ecosystem diversity.

 1.      Species diversity

Species is a group of living organisms that can interbreed with each other. Species diversity is the different kinds of species within a particular region or it is diversity between species. For example, in a small river there can be plants, frogs, fishes, snakes and so forth, forming the diversity of species. Species diversity is also known as Taxonomic diversity or Organismal diversity. Species diversity is measured as species richness. Species richness is the total count of a species in a defined area. Species abundance refers to the relative number among species. If all species have equal abundance means species variation is high, means high species diversity. Species diversity is dependent on the climatic conditions. 

2.        Genetic diversity 

Genetic diversity is genetic differences within  each species.  Gene is the distinct sequence of DNA forming part of the chromosome which offsprings inherit from their parents. Chromosomes, genes and DNA determine the uniqueness of each individual and each species. Genetic diversity is the variety of genetic information contained in all of the individual plants, animals and microorganisms occurring within the population of a species. In other words,  genetic diversity refers to different types of genes in chromosomes of species and their variations. For example,  within the species of dogs, different varieties like Bulldog, German Shepherd, Great Lane dog etc. are found. It is due to differences in their genes. Even within such varieties, they differ in their  size, shape, colour etc and  this is due to the difference within their genes. 

3.        Ecosystem diversity

Ecosystem diversity is the diversity at ecological or habitat level. Ecosystem is a biological community of animals and plants that interact with each other as well as with their environment in a particular region. Ecosystem diversity refers to a particular assemblage and interaction of a species living together and their physical environment in the given area. It is also called ecological diversity. For example, there may be two different forests in an.area. The species in each ecosystem, natural communities and habitats will be different from each other. This is called ecosystem diversity.

Biodiversity distribution is not uniform on earth. Terrestrial biodiversity is highest near the equator because of warm climate and high primary productivity. Similarly, marine biodiversity is highest along the coast where surface temperature is highest. Biodiversity is the life support system. Organisms depend on it for the air they breathe, for the food they eat and for the water they drink. Biodiversity is the essence of life and human beings form an integral part of it and upon biodiversity we are fully dependent. Hence, the conservation of biodiversity is essential for the existence of living forms including human beings on the earth.

References:

1. Dickson Adom, Krishnan Umachandran, Parisa Ziarati, Barbara Sawicka and Paul Sekyere, 2019. The Concept of Biodiversity and its Relevance to Mankind: A Short Review, Journal of Agriculture and Sustainability, 12 (2); 219-231.
2. Rawat U S and Agarwal N K, 2015. Biodiversity: Concept, threats and conservation, Environment Conservation Journal, 16(3); 19-28.
3. Krishnamurthy K V, 2003. Textbook of Biodiversity, Science Publishers Inc. USA