Bio-geographical Zone of India

and Major Vegetation

Presented byVivek Kumar

SinghM.Sc. 2nd semester

Under the Supervision of

Prof. N. B. Singh

What is Bio-geography?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.

IndiaIndia is a vast country, acquiring

32,87,263 square kilometer land area.It is 7th largest country of the world.It is situated in Northern Hemisphere.It is situated on Indo-Australian Plate.It is divided in to 10 bio-geographical

zone.It has 4 hotspot Zone.

A Cartogram showing different zones of India.

1.Trans HimalayanThis zone is estimated 1 lakh, 86

Thousands and 200 km2. Himalayi mountain region is bow

shaped, situated in North West of India. Virtually this entire zone in India is in

Lahul-Spiti district of Himanchal Pradesh and in Laddakh.

The mountains of this region have the richest wild sheep and goat community in the worlds with eight distinct species and subspecies.

2. Himalayas

The Himalayas consist of the youngest mountain chains in the world.

The forests are very dense with extensive growth of grass and evergreen tall trees.

Oak, chestnut, pine, deodar are abundant in Himalayas.

There is no vegetation above the snowline.

Several interesting animals live in the Himalayan ranges. Chief species include wild sheep, mountain goats, shrew, Panda and snow leopard are found here.

3. Indian DesertThis region consists of parts of

Rajasthan, Kutch, Delhi and parts of Gujarat.

The climate is characterized by very hot and dry summer and cold winter.

Rainfall is less than 70 cm. The plants are mostly xerophytic,

Babul, Kikar, wild palm grows in areas of moderate rainfall.

Indian Bustard, a highly endangered bird is found here. Camels, wild asses, foxes, and snakes are found in hot and arid deserts.

4. Semi-AridAdjoining the desert are the semi-arid

areas, a transitional zone between the desert and the denser forests of the Western Ghats.

The natural vegetation is thorn forest. Thorny scrubs, grasses and some

bamboos are present in some regions. A few species of xerophytic herbs like

Acacia, Balanites, Capparis and Grewia.The Asiatic Lion is restricted only in Gir

National park in Gujrat, in this region.

5. Western GhatThis zone extends from Kanyakumari in

south to Tapti river in north. The ghat is situated on 2700 m elevation from sea level.

The zone is rich in evergreen forest. It has 4000 species of higher plants, which account of 27% of India’s 15000 species. There are 1800 endemic species in the region.

The rainfall is heavy about 2000 mm. Forest have been replaced by tea, coffee,

cocoa, rubber, cardamom, Chincona. The sub-tropical forest occur in Anaimalai

and Nilgiris hills at an altitude of 1800 m. This zone have large population of Nilgiri Langur, Tiger, Leopard, Indian Elephant etc.

6. Deccan PeninsulaIt covers 43% of Indian sub-

continent. The zone does contain some more

conserved forest area of India in MP, Maharashtra and Orissa.

It is the premier area for the deciduous forest, thorn forest. Only a small area evergreen forest occur.

Plants are mostly Tectona grandis, Shorea robusta, Acacia, Albizia amara and Hardwickia.

Most wild life species are widespread throughout the zone, e.g. Chital ,sambhar, Nilgai, Chowsingha, Elephant.

Tigers are absent from this region.

7. Gangetic PlainThis is the largest unit of the Great

Plain of India. Ganga is the main river after which this plain is named.

This is divided in to Three zone-i. Upper plain of Ganga (from Delhi to

Allahabad)ii. Middle plain of Ganga (from Allahabad

to Bihar)iii. Lower plain of Ganga ( in West

Bangal)This is one of the most fertile area. This is 2400 km. in length and 240-

320 km in width.The trees belonging to these forests

are Teak, Sal, Shisham, Mahua, Khair etc.

8. North-East IndiaOf all zone in India, perhaps this zone is

richest in communities, in species and in endemics.

About 40% of total surface area distributed in states of Assam, Manipur, Meghalaya, Mizoram, Nagaland & Tripura is forest.

Botanically, Khasi- Jaintia hills of Meghalaya are known as one of the richest zone in Asia.

North –East India is the transition zone between the Indian, Indo-Malayan, and Indo-Chinese region.

9. Island

There are two islands, 1- Andaman and Nicobar island, located in bay of Bengal.2- Lakshadweep island, located in Arabian Sea and consist of 43 small islands.Andaman and Nicobar island consist 348 islands, stretching about 590 km. In this zone tropical rain-forest is high. Here 86% area is legally under forest. In deciduous forest Terminalia is common. It is recently declared as a hot- spot because of the richness of endemic species.

10. CoastIndia has a coastline of 7,516.5 km. The Indian coasts extending from Run

of Kutch to Bangladesh. The West coast is narrow and

extending from Gulf of Cambay to South. The West coast is 50-65 km. wide.The Eastern coast is extending from Bay

of Bengal to South with Eastern ghat.The east coast is 450-750 km. wide.Larger parts of the coastal plains are

covered by fertile soils on which different crops are grown. Rice is the main crop of these areas. Coconut trees grow all along the coast.

Major VegetationNatural Vegetation= The naturally growing

plant cover without human aid, is called natural vegetation.

The vegetation which is undisturbed by the human is called virgin vegetation.Five types of major natural vegetation

available in India are as follows:1. Tropical Evergreen Rainfall region.2. Tropical Monsoon Forests

(1. Moist deciduous, 2. Dry Deciduous)3. Thorny Forests & Bushes4. Mountain Forests 5. Tidal Forests

1. Tropical Evergreen Rainfall region

These forests are found over areas where the dry season is short and the rainfall in more than 200 cm. The trees do not shed leaves at any time of the trees and hence the ‘evergreen’ nomenclature. The trees reach a height of over 50 meters.

Tree attain a height of 60 meter.These forests are common on the

rainy slopes of the Western Ghats and the hills of Assam and Andmaan Nicobar.

The wood of these forests is hard. The commercially useful varieties include rosewood, ebony and mahogany.

2. Tropical Monsoon Forests

The trees in these forests shed their leaves for about six to eight weeks in summer.. The rainfall suited for such forests is between 75 to 200 cm.

They are also called deciduous forests. Teak and Sal are the most important trees of these forests. Teak is important species of the moist deciduous. Sal is of the dry deciduous variety. Other important trees are sandalwood and rosewood.

The wood from these forests is used for making furniture, building purposes and for making small boats. Teak grows abundantly on the Western and Eastern Ghats.

3. Thorny Forests & BushesThorn forest grow in those region which

receive less than 70 cm of rainfall.This type of vegetation is found in the North-

Western part of India i.e. Gujrat, Raj., Madhya Pradesh.

The main plant species is Acacia, Palm, Euphorbia, and Cactus.

Tree are scattered and they have long root, which go very deep in the ground.

The stem is succulent to conserve water. Leaves are usually modified in to spine. E.g. Opuntia.

The stem is modified in to thorn. E.g. Cactus.

4. Mountain ForestsThe forest in the mountainous area are called

as mountain forest. Different type of vegetation found at different altitudes in the mountain.

The wet temperate type of forest is found between a height of 1000 and 2000 meter. Evergreen broad leaf trees such as oak and chestnut found in such forest.

Temperate forest are found between the height of 1500-3000 meter. Pine, deodar, cedar is common on this elevation.

Alpine vegetation are found on a height of 3600 meter or more.

5. Tidal ForestsThey are also called as Deltai forest and

Mangrove forest.In India, they are part of the forests in the

delta regions of rivers Ganga and Brahmaputra, Kaveri, Krishna, Godavari and Mahanadi.

The Sundarbans, named after the tree Sundari.

Because of saline water the plants became hard. Wood is used to make boats.

Sundarban is a biosphere reserve, and Royal Bengal Tiger is protected here.