Biodiversity

Embracing Nature for a Better Future

Biogeographic
Zones in India
1. Trans – Himalayan Region
2. The Himalayan Ranges
3. Western Ghats
4. The Desert Regions
5. The Deccan Plateaus
6. The Gangetic Plain
7. North-East India
8. Islands
9. The Semi – Arid Area
10. Coasts
Trans – Himalayan Region
The Trans-Himalayas Mountain Region or Tibet Himalayan Region is located to the north of the Great Himalayas which
is a vast stretch of cold, mountainous snow – covered region covering the entire Tibetan plateau, Karakoram, Ladakh and Lahul
– Spiti district of Himachal Pradesh (India), Zaskar and Kailash mountain ranges. This region constitutes for 5.6 percent of the
country’s geographical area. They stretch in an east-west direction for a distance of about 1,000 km. Their average elevation is
approximately 3000 meters above mean sea level.
This zone has sparse alpine steppe vegetation. The mountains here have the richest habitat of wild sheep and goats. The
region has a herbivore community (rabbits) consisting of Tibetan antelope, gazelle, wild yak and blue sheep. Other
characteristic animals found are snow leopard, Tibetan wolf, ibex, marbled pole cat, Himalayan marmot etc.
 The Himalayan Ranges
The Himalayan zone makes India one of the richest areas in terms of habitats and species. this zone covers 6.4 percent
of the total geographical area and has alpine and sub-alpine forests, grassy meadows and moist deciduous forests. The range
of the main Himalayas stretches for a distance of over 2,400 km from the Indus Gorge in the west to the Brahmaputra Gorge in
the east. The Himalayan Ranges are further subdivided into Greater Himalayas, Inner or Middle Himalayas, and Shiwalik.
The Himalayan zone has diverse habitats for a range of species including endangered ones such as Hangul (Cervus eldi
eldi) and Musk Deer (Moschus moschiferus). In lower subtropical belt mixed deciduous forests occupy lowest elevations, they
are replaced by chir pine (Pinus roxburgii) and then by banj oak (Quercus leucotrichophora) at around 2000m elevations.
The Indian
Desert
It is the severely dry area west of the Aravalli mountain range,
which contains both the saltwater desert of Gujarat and the sand
desert of Rajasthan. It constitutes 6.6 percent of the country’s
geographical area. The Indian desert, which mostly includes
Rajasthan’s western and northwestern parts as well as a portion of
Gujarat’s Kachchh region in the southwest, marks India’s northern
border. At the Aravalli range in the east, it is 350–450 meters above
sea level; in the south and west, it is 100 meters; and in the Rann of
Kachchh, it is 20 meters. Numerous endangered mammal species,
including the wolf (Canis lupus), caracal (Felis caracal), desert cat
(Felis libyca), and birds of conservation concern, such the houbara
bustard (Chamydotis undulate) and the great indian bustard (Ardeotis
nigriceps), can be found there in huge tracts of grassland.
Semi-Arid
The semi-arid region accounts for 16.6% of the total geographical area.
It is a transition zone between the desert and the dense forests of the
Western Ghats. Peninsular India has two large semi-arid regions. This
semi-arid region also has several artif icial and natural lakes, as well as
marshy lands. This zone includes the Punjab plains, Delhi, Haryana,
Jammu and Kashmir's fringes, Himachal Pradesh's western edges,
eastern Rajasthan, eastern Gujarat, and northwest Madhya Pradesh.
The area is distinguished by discontinuous vegetation blanketed with
bare soil and soil water that is in short supply all year. In Western India,
the Semi-arid zone is characterised by savannah woodland, dry
deciduous forest, and tropical thorn forest. The heart of this zone is the
Aravalli System, which is home to two types of vegetation: tropical dry
deciduous forest and tropical thorn forest.
The cervid species Sambar (Cervus unicolor) and Chital (Axis axis) are
restricted to better wooded hills and moister valley areas, respectively.
The Lion (Panthera leo leo), an endangered carnivore species (restricted
to a small area in Gujarat), Caracal (Felis caracal), Jackal (Canis aureus),
and Wolf (Canis lupus) are among the endangered species found in this
region.
Western
Ghats
The Western Ghats account for 4% of the total geographical area.
The zone is one of the world's 25 biodiversity 'hotspots' and one of
India's major tropical evergreen forested regions, with enormous plant
diversity. These run along the west coast of peninsular India from the
Tapti river in the north to Kanyakumari in the south, passing through the
states of Gujarat, Maharashtra, Goa, Karnataka, Tamil Nadu, and Kerala.
The region is home to nearly 4000 species of f lo wering plants,
accounting for nearly 27% of India's total f lora. Over 1500 of these
species are endemic.
The region is hom e to m ost of the vertebrate species found in
peninsular India, as well as an endemic faunal element.
Nilgiri Langur (Presbytis jobni), Lion Tailed Macaque (Macaca silenus),
Grizzled Giant Squirrel (Ratufa macroura), Malabar Civet (Viverricula
megaspila), Nilgiri Tahr (Hemitragus bylocrius), and Malabar Grey
Hornbill (Ocycerous griseus) are all endemic to this region.
Deccan
Plateau
The Deccan Plateau is India's largest biogeographic region, accounting
for 42% of the total geographical area.
It is a semi-arid region located in the rain shadow of the Western Ghats.
The zone is relatively homogeneous, with climates ranging from semi-
arid to moist-deciduous/semi-evergreen.
This bio-geographic zone of peninsular India is by far the most
extensive, covering India's f in est forests, particularly in the states of
Madhya Pradesh, Maharashtra, and Odisha.
The Vindhya and Satpura hill ranges, the Chhota Nagpur Plateau, the
Eastern Ghats, the Tamil Nadu Plains, and the Karnataka Plateau are all
part of the central highlands. Species found in this region include: Chital
(Axis axis), Sambar (Cervus unicolor), Nilgai (Boselapbus tragocamelus),
Chousingha (Tetracerus quadricornis), Barking deer (Muntiacus muntjak),
Gaur (Antilope cervicapra), Elephant (Elephas maximus) in Bihar-Orissa
and Karnataka-Tamil Nadu belts.
 The Gangetic Plain
The Gangetic Plain accounts for about 10.8 percent of the total geographical area. The Gangetic plain is topographically
homogeneous for hundreds of kilometers. The Gangetic divide, the Upper Gangetic Plain, the Middle Gangetic Plain, and the
Lower Gangetic Plain are all part of this zone. This zone, which stretches from eastern Rajasthan through Uttar Pradesh to
Bihar and West Bengal, is mostly agricultural and has a dense human population. The Gangetic plain encompasses the Terai-
Bhabar tracts of Uttar Pradesh, Bihar, and West Bengal.
Teak, Shisham, Sal, Khair, and other trees from these forests have some of the highest population densities and topographic
uniformity. This region's fauna includes the Rhinoceros unicornis, Elephant (Elephas maximus), Buf falo (Bubalus bubalis),
Swamp Deer (Cervus duvauceli), Hog-Deer (Axis porcinus), and Hispid Hare (Carprolagus bispidus).
 North Eastern Region
The North East Region accounts for 5.2 percent of the total geographical area. This region is a transition zone between the
Indian, Indo-Malayan, and Indo-Chinese bio-geographical regions, as well as a meeting point for the Himalayan mountains and
Peninsular India. The North-East is thus a biogeographical 'gateway' for much of India's fauna and f lora, as well as a
biodiversity hotspot (Eastern Himalaya).
Many of the species that contribute to this biological diversity are either restricted to the region itself or to smaller localised
areas of the Khasi Hills.
Islands
This zone, which accounts for 0.3% of India's total geographical area, is one
of the three tropical moist evergreen forest zones.
The islands are home to unique f lora and fauna. These islands are high
endemism hotspots, with some of India's f in est evergreen forests and a
diverse range of corals.
The islands are divided into two major groups: the Lakshadweep Islands
and the Andaman Islands.

Lakshadweep Islands

The Lakshadweep Islands are a group of 27 small islands located in the Arabian Sea.
They are 320 kilometres from Kerala's coast.

The Lakshadweep is made up of 25 coral islets with a typical reef lagoon system rich
in biodiversity. However, the densely populated Lakshadweep islands have almost
no natural vegetation.
Islands
Andaman Islands

The Andaman and Nicobar Islands are a 348-island group in the Bay of Bengal that
runs north-south.

The Andaman Islands are about 190 kilometres from the nearest point on the
mainland, Cape Negrais in Burma.

The Great Andaman (300 km long) is made up of five islands that are close together,
with the Little Andaman to the south.

The Nicobar groups of islands are separated from the Andamans and from one
another by 800 m deep channels.

Some of the endemic fauna of the Andaman and Nicobar Islands include the
Narcondam hornbill and the South Andaman krait.
 Coastal Regions
India has a vast and elaborate coastline of approximately 7,500 km along the Arabian Sea in the west and the Bay of Bengal in
the west. The western coast is much narrower than the East coast. They have an average width of about 65 km. It extends
from Gulf of Cambay in the north to Cape Comorin (Kanya kumari). It is characterised by the presence of estuaries, lagoons and
backwaters. The largest lake present have is Vembanad lake. The eastern coastal plains extent from Subarnarekha river to
Kanyakumari. It is formed by alluvial f il lings of rivers like Mahanadi, Godavari, Krishna and Kaveri. They are wider and
extensive than the western coats with an average width of 120 km. The Coastal plains are covered by fertile soils on which a
variety of crops are cultivated. Rice is the main crop of these areas. Coconut trees grew along the coast. This region has high
tiger population along with the presence of animals like Dugong, dolphins, salt-water crocodile, marine turtles, tortoises,
hump – back dolphin etc.
Ecological
Problems
1. Loss of Species and Biomass: Human activities are responsible for the
majority of threats to species, sites, and habitats.
2. Changes in Climatic Conditions: When a forest is cut and burned to
make way for cropland and pastures, the carbon stored in the tree
trunks combines with oxygen and is released into the atmosphere as
CO2. This amplifies the greenhouse e ect and contributes to rising
global temperatures.
3. Drying up of rivers and aquifers: Rivers and aquifers are drying up as a
result of increased forest removal. Reduced rainfall reduces the
percolation of water in the underground, lowering the levels of the
underground water-table.
Ecological
Problems
1. Floods and Droughts: As CO2 levels rise in the atmosphere,
temperatures rise, resulting in floods and droughts. Water evaporates
quickly as a result of the high temperature. Eroded soil that lacks
vegetative cover cannot retain moisture for long. As a result, this
causes droughts.
2. Desertification: The continuous expansion of deserts into previously
semi-arid regions is a serious manifestation of the long-term e ects of
land degradation and intensive soil erosion.
3. Rapid melting of glaciers: This is a result of global warming, which is
depleting the sources of fresh water for our rivers and streams that
flow from the Himalayan ranges.
Conclusion
Biodiversity is essential to all life on Earth. Many resources have been depleted
as a result of increased human activity, paving the way for global warming,
climatic changes, habitat loss, and ecosystem imbalance. It also has an ef fect
on human health because of dangerous diseases caused by various types of
pollution. Biogeography has been used in one of the major recent approaches
to classifying India's ecosystems. The main goal of this exercise was to create
a biogeographical classif ic ation based on existing data that will allow
conservation planning at both the national and state levels.
Thank You