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Essay On Endemism

Endangered and Endemic species of India

A plant, animal or microorganism that is in immediate risk of biological extinction is called endangered species or threatened species.
In India, 450 plant species have been identified as endangered species. 100 mammals and 150 birds are estimated to be endangered.
India's biodiversity is threatened primarily due to:
  1. Habitat destruction
  2. Degradation and
  3. Over exploitation of resources
The RED-data book contains a list of endangered species of plants and animals. It contains a list of species of that are endangered but might become extinct in the near future if not protected.
Some of the rarest animals found in India are:
  1. Asiatic cheetah
  2. Asiatic Lion
  3. Asiatic Wild Ass
  4. Bengal Fox
  5. Gaur
  6. Indian Elephant
  7. Indian Rhinocerous
  8. Marbled  Cat
  9. Markhor
Extinct species is no longer found in the world.
Endangered or threatened species is one whose number has been reduced to a critical number. Unless it is protected and conserved, it is in immediate danger of extinction.
Vulnerable species is one whose population is facing continuous decline due to habitat destruction or over exploitation. However, it is still abundant.
Rare species is localized within a restricted area or is thinly scattered over an extensive area. Such species are not endangered or vulnerable.
A few endangered pecies in the world are listed below:
  1. West Virginia Spring Salamander (U.S.A)
  2. Giant Panda (China)
  3. Golden Lion Tamarin (Brazil)
  4. Siberian Tiger (Siberia)
  5. Mountain Gorilla (Africa)
  6. Pine Barrens Tree Frog (Male)
  7. Arabian Oryx (Middle East)
  8. African Elephant (Africa)
Other important endangered species are:
  1. Tortoise, Green sea Turtle , Gharial, Python (Reptiles)
  2. Peacock, Siberian White Crane, Pelican, Indian Bustard (Birds)
  3. Hoolock gibbin, Lion-tailed Macaque, Capped mokey, Golden monkey (Primates)
  4. Rauvol fia serpentina (medicinal plant), Sandal wood tree, etc
  1. Human beings dispose wastes indiscriminately in nature thereby polluting the air, land and water. These pollutants enter the food chain and accumulate in living creatures resulting in death.
  2. Over-exploitation of natural resources and poaching of wild animals also leads to their extinction.
  3. Climate change brought about by accumulation of green houses gases in the atmosphere. Climate change threatens organisms and ecosystems and they cannot adjust to the changing environmental conditions leading to their death and extinction.
An international treaty to help protect endangered wildlife is, "Convention on International Trade in Endangered Species 1975" (CITES). This treaty is now signed by 160 countries.
  1. CITES lists 900 species that cannot be commercially traded as live specimens or wildlife products as they are in danger of extinction.
  2. CITES restricts trade of 2900 other species as they are endangered.
  1. This treaty is limited as enforcement is difficult and convicted violators get away by paying only a small fine.
  2. Member countries can exempt themselves from protecting any listed species.
Endemic species of India
Species that are found only in a particular region are known as endemic species. Almost 60% the endemic species in India are found in Himalayas and the Western Ghats. Endemic species are mainly concentrated in:
  1. North-East India
  2.  North-West Himalayas
  3. Western Ghats and
  4. Andaman & Nicobar Islands.
Examples of endemic Flora species are
  1. Sapria Himalayana
  2. Ovaria Lurida
  3. Nepenthis khasiana etc
Endemic fauna of significance in the western ghats are:
  1. Lion tailed macaque
  2. Nilgiri langur
  3. Brown palm civet and
  4. Nilgiri tahr
Factors affecting endemic species:
  1. Habitat loss and fragmentation due to draining and filling of inland wetlands.
  2. Pollution also plays an important role.
  1. Frog eggs, tadpoles and adults are extremely sensitive to pollutants especially pesticides.
  2. Over-hunting and
  3. Populations can be adversely affected by introduction of non active predators and competitors. Disease producing organisms also play an important adversary in reducing populations of endemic species.

Endemic species can be defined as those species which are confined only to a particular locality. Such organisms are very important from the point of view of conversation as their disappearance means extinction of the species as they are not found anywhere else.

No doubt endemism represents a unique step in the process of evolution which could be perpetuated and sustained only in the locality concerned by imperfectly understood attributes of environmental quality. The diversity of life forms which we see around us has essentially evolved by a method of trial and error. In the process of natural selection, changes which confer some disadvantage to the organism are eliminated while those changes which are advantageous are retained.

It is the environment only which is instrumental in the operation of the process of natural selection. This makes the habitats in which endemic species thrive very important. The importance of the habitat or locality is further highlighted by the fact that in most of the cases such localities possess a number of endemic species distributed in several taxonomic categories or groups. The endemism in a particular taxonomic category is usually matched by more or less similar degree of endemism in other taxonomic groups.

Naturally the endemic species and the habitats which are likely to be lost forever should receive urgent conservation attention. Based on the degree of endemism in species composition, Myers (1988) has identified 12 such localities in tropical regions of world which require urgent conservation attention.

These areas are spread over 292,000 sq. kms only and represent barely 0.2% of the earth's total land surface. Of the world's 8.34 million sq. kms of primary forests, these hot-spots of biological diversity represent only 3.5%. However, they possess 34,400 endemic plant species which is about 27% of all tropical forest species or 13% of the total plant species found on earth. In 1990, Myers identified another eight hot-spots of endemic species diversity in other climatic regions of the world. These are:

1. California, Western Floral Province

2. Central Chile.

3. Ivory coast

4. Cape Floral Province, Africa

5. Western Ghats, India.

6. Sri Lanka.

7. South-west Australia.

8. Eastern Arc Province, Tanzania.

These eight hot spots of biodiversity cover 454,400 sq. kms or only 0.3% of world's total land surface but possess 15,555 endemic species of plants representing 6% of the total number of species of plants world-wide. Thus about 49,955 endemic species of plants occur in an area barely 786,400 sq. kms or only 0.5% of the world's total land area.

On worldwide basis about 4.9% of earth's lam surface has been set aside as nationally protected areas. However, much of earth's hot-spots of biodiversity which comprise only one tenth of this area are not protected at all. Instead of badly managed 5% properly managed 0.5% of earth's land surface on which stand these hot-spots of biodiversity, could serve the purpose of conservation efforts in a much better way.


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