SPECIES

Concept, Classification And Different Roles In The Environment 

SPECIATION

Speciation is how a new kind of plant or animal species is created. Speciation occurs when a group within a species separates from other members of its species and develops its own unique characteristics.

TYPE OF SPECIES &  ITS ROLE IN ENVIRONMENT:

1. KEYSTONE SPECIES: A keystone species is a species that plays an essential role in the Structure, Functioning Or Productivity of a habitat or ecosystem at a defined level (habitat, soil, seed dispersal, etc).

Examples include the Elephant’s Role in maintaining habitat structure, and bats and insects in pollination. Disappearance of such species may lead to significant ecosystem change or dysfunction which may have knock on effects on a broader scale.

2. UMBRELLA SPECIES: The species requiring large areas of natural habitat for their continued survival. Ex : Giraffe
3. FLAGSHIP SPECIES: The species selected to act as an ambassador, icon or symbol for a defined habitat, issue, campaign or environmental cause.

Ex : Koala , Panda . By focusing on them, their habitat and other species which share the same habitat can also be conserved.

4. INDICATOR SPICES – An indicator species is a species or group of species chosen as an indicator For Example corals as indicators of marine processes such as siltation, seawater rise and sea temperature fluctuation.
5. Endemic species – An “Endemic Species” is one that is only found in a particular region and nowhere else in the world. Example Sangai Deer, Lion Tailed Macaque, Nilgiri Tahr.

Since these species are not widespread and may be confined to only one or two protected areas, they are of great conservation concern. A plant may be said to endemic to a certain state, to a country or to a continent.

ENDEMISM

The term ‘endemism’ was coined by A.P. de Candolle (1855) for the distribution of an organism (Plant, Animal Or Microorganism) in a limited geographical area. In Ecological terms, it states that a plant or an animal lives only in a particular location, such as a specific Island, Habitat Type, Nation Or other defined zone.

FACTORS RESPONSIBLE FOR ENDEMISM

1. The natural crossing among the closely related plants growing under favourable conditions and Mutations.
2. Endemism is found in isolated e.g., islands, isolated areas etc. Mountains also have more endemic species as they are isolated e.g., 70% sp. of Himalayas is endemic.
3. Climate also is one of the factors e.g., North of Himalaya is dry plateau of Tibet and South Himalayan range has alluvial fertile soil. Maximum endemic plants are found in the Himalayas and South India. Indo-Gangetic plains have a very small number of endemic species.

ENDEMIC SPECIES OF INDIA

According to the fifth report of convention of Biological Diversity (CBD) 2014 reported by Botanical survey of India  The numbers of endemic plant under different plant groups  nearly about 4045 species of flowering plants (angiosperms) endemic to India are distributed amongst 141 genera belonging to 47 families. Some examples of endemic plant species of India are Rhododendron, Teak, Mango, Tamarind, Neem,  the endemic animal species found in India are Lion-Tailed Macaque, Nilgiri langur, Brown Palm Civet And Nilgiri tahr.

These are concentrated in the floristically rich areas of North-east India, the Western Ghats, the North-west Himalaya and the Andaman and Nicobar Islands..

ENDANGERED SPECIES

Endangered species are any species that is at risk of extinction because of a sudden rapid decrease in its population or a loss of its critical habitat.

An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species

Example :

Any species of plant or animal that was threatened with extinction could be called an endangered species. The need for separate definitions of “endangered” and “threatened” species resulted in the development of various categorization systems. Each containing definitions and criteria by which a species can be classified according to its risk of extinction.