Unit – 4
Biodiversity And Conservation
Biodiversity: Bio = Diversity = Variety
The term Bio-Diversity was first coined by Walter G. Rosen in 1986. Biodiversity, refers to the variety of life on Earth. It includes diversity of ecosystems, species and genes, and the ecological processes that support them. Everything that lives in an ecosystem is part of the web of life, including humans. Each species of vegetation and each creature has a place on the earth and plays a vital role in the circle of life. Plant, animal, and insect species interact and depend upon one another for what each offers, such as food, shelter, oxygen, and soil enrichment. Maintaining a wide diversity of species in each ecosystem is necessary to preserve the web of life that sustains all living things.
There are three levels of Diversity
- Species diversity
- Genetic diversity
- Ecosystem or Habitat diversity
Species diversity: The species diversity peaks in the tropical forest and coral reefs. India has around 2,00,000 species of the total species described.It is defines as variety of different species of living forms in a given area.
Genetic diversity: These variations help the individuals to have a variant that help it to be suite for the new environment. The more genetic diversity in a population, the more chances in variations.
Ecosystem or Habitat diversity: Ecosystem is the structural and functional unit of the biosphere. Ecosystem diversity is defined as „the aggregation of various habitats, community types and abiotic environment in a given area‟. India has one of the richest ecosystem diversities, ranging from deserts, plains, hills, mangroves, rainforests to cold Himalayas. Out of the 18 hot spots of biodiversity recognized in the world, India has two of them, Eastern Himalaya and The Western Ghats. Eastern Himalayas is recognized as the “Cradle of Speciation” due to rich diversity of primitive flowering plants.
Bio-geography is the study of the origin of world biota, environmental relationship and distribution of organism, both past and present, over the face of earth. India is mega diversity country with different types of climate and topography in different parts. Variations due to the variability in flora and fauna . It is important to study and know the distribution, evolution and environmental relationship of plants and animals. To know about the relationship of flora and fauna, biogeographers classified India into ten biogeographic zones . They are :
- Trans-Himalayas
- Himalayas
- Dessert
- Semi-arid
- Western Ghats
- Deccan Peninsula
- Gangetic Plain
- Northeast India
- Islands
- Coasts
Biodiversity patterns occur within species, communities, habitats, regions, ecosystems, biomes and the entire Earth. The within-species diversity is studied as genetic diversity and refers to the total number of characteristics in the genetic composition of a species. A biodiversity hotspot is a biogeography region with a significant reservoir of biodiversity that is threatened with destruction. An area is designated as a hotspot when it contains at least 0.5% of plant species as endemic. There are 25 such hotspots of biodiversity on a global level, out of which two are present in India These are: Indo-Burma (earlier The Eastern Himalayas) and The western Ghats & SriLanka. These hotspots covering less than2% of the world’s land area are found to have about 50% of the terrestrial biodiversity.
Endangered species of India: When the number of species has been reduced to a critical level . Unless it is protected and conserved, it is in immediate danger of extinction. Unless it is protected and conserved, it is in immediate danger of extinction- 150 birds species, 100 mammals species ,450 plant species. India’s biodiversity is threatened due to habitat destruction, degradation and over exploitation of resources.
Endemic Species: Species found only in particular region . In India 47,000 species and 7000 plants are endemic . 62% of our endemic species are found in Himalayas and Western Ghats
1. Fauna – Animals present in a particular region 1. 81,000 species of animals
2. Flora – Plants present in a particular region
Habitat loss : Habitat loss & degradation are major causes of species extinction, affecting 89% of all threatened birds, 83% of mammals & 91% of all threatened plants assessed globally. The main causes of habitat are agriculture activities, Mining, development of human settlement, industry etc.
Poaching of Wildlife: Poaching is another threat that has emerged in recent decades as one of the primary reason for decline in number of species. Wildlife is sold and traded in many countries for live specimens, folk medicines, furs, Skin, and other products such as Ivory, horns etc amounting to millions of dollars.
Man –wildlife conflicts: The conflict between man and wildlife started with the evolution of man, but intensity increased due to the activities of modern man. Due to the lack of stable food and disruption of movement, wild animals came out of forest area and attack the agricultural field and humans and in turn got killed by the humans.
In-situ conservation: It simply means conservation of species in its natural ecosystem or even in manmade ecosystems. This strategy emphasizes protection of total ecosystem through a network of “protected area”. Protected Areas: an area of land and / or sea specially dedicated to the protection and maintenance of biological diversity and managed through legal effective means. There are different categories of protected areas which are managed with different objectives. These include; Biosphere reserves, National parks, Wild Life Sanctuaries etc.
Ex-situ conservation: It is defined as “the conservation of component of biological diversity (Sample of genetic diversity, particularly of endangered species) outside their natural habitats”. It involves maintenance and breeding of endangered plant and animal species under partially or wholly controlled conditions. E.g. Zoos, Botanical Gardens, Aquaria, Nurseries, DNA bank, Seed bank, Gene bank etc.
Economic values: Biodiversity provides humans with raw materials for consumption and production. Many livelihoods, such as those of farmers, fishers and timber workers, are dependent on biodiversity.
Ecological values : Biodiversity provides functioning ecosystems that supply oxygen, clean air and water, pollination of plants, pest control, wastewater treatment and many ecosystem services.
Ethical values : This related to biodiversity conservation are based on the importance of protecting all forms of life against illegal activities like cloning of animals, smuggling of valuable biodiversity instances, bio-piracy, illicit trade etc.
Aesthetic Values: Beautiful nature of plants and animals is the most important value of biodiversity is eco – tourism.
Reference Books
- Biodiversity and its conservation in India by Sharad Singh Negi
- Biodiversity conservation by Asish Ghosh
