Bio-geography of India
- Biogeography is the study of distribution of biological species and ecosystems in geographical space and geological time.
Some Basic Concepts-
Realm-
- It is typically defined by physical features such as climate, topography, and soil type, and it can span multiple countries or even continents.
- The realm concept is commonly used in the field of biogeography to study patterns of biodiversity and to understand the distribution and evolution of species.
Biomes-
- A biome refers to a naturally occurring community of plants and animals that exist in a particular habitat, such as a forest or tundra, on a large scale.
Biogeographic zone-
- It represents a geographical area having similar species of plants and animals, communities, ecosystems, and ecology.
Biotic province-
- A biotic province refers to a geographic region that is inhabited by a distinct and unique set of organisms, which are separated from other regions by barriers that limit or prevent migration and movement of species.
Each Realm is divided into Biogeographic zone and each biogeographic zone is further divided into biotic provinces
Facts about India
- India has 2 Reals and 5 Biomes.
- India is divided into 10 bio-geographic zones.
- There is total 27 biotic provinces (as per revised classification).
Realms of India
1) The Himalayan region represented by Palearctic Realm and
2) The rest of the sub-continent represented by Malayan Realm
Note- In the world there are total Eight terrestrial biogeographic realms
Biomes of India
1) Tropical Humid Forests.
2) Tropical Dry or Deciduous Forests (including Monsoon Forests).
3) Warm deserts and semi-deserts.
4) Coniferous forests .
5) Alpine meadows.
10 bio-geographic zones of India
Zone 1-
- The Trans-Himalayan
This zone is referred as 'high-altitude cold desert' with characteristic sparse tree-less vegetation.
Distribution (3 biotic provinces)-
- Ladakh Mountains-Kargil, Nubra , and Zanskar in Jammu & Kashmir, and Lahaul and Spiti in Himachal Pradesh.
- Tibetan plateau- eastern Ladakh and adjacent parts of Spiti
- Sikkim Plateau.
Flora-
- Sparse alpine steppe, Alpine herbaceous formations.
Fauna-
- Wild sheep, goat, The snow leopard, black and brown bears, wolf, marmots, marbled cat, ibex, and kiang, wild yak, ass, gazelle, and four horned antelope, snow leopard, Tibetan wolf etc.
Zone 2: The Himalaya
- It has variety of ecosystems ranging from species-rich tropical and sub-tropical broadleaf wet forests equivalent to tropical rain forests.
This zone is divided into four biotic provinces –
- North-West Himalaya.
- West Himalaya,.
- Central Himalaya.
- East Himalaya.
Flora-
- Oak, Rhododendron, Aesculus indica, Acer, Cassiope, Juniper.
Fauna-
- This egion is home to a diverse range of wildlife species, including the Tibetan Ass, Sikkim Stag, Himalayan Musk Deer, Sambar, Tahr, Beharal, Ibex, Mishmi Takin, Sun Bear, Wild Boar, Gibbon, Binturong, Red Pandas, Lesser Cats, Jungle Fowl, Markhor, Serow, Koklas, and Himalayan Monal.
Zone 3: The Indian Desert
- This zone occupies north western India spreading over western Rajasthan and the Rann of Kutchh in Gujarat, accounting 6.5 % of India's total geographical area.
This zone is divided into two biotic provinces –
- The Thar desert receives an annual rainfall that varies from less than 100mm in the west to 500mm in the east.
- The high temperatures, minimal rainfall, and strong winds in the Thar desert result in the formation of rolling sand dunes.
- The Great Rann of Kutch lies to the south of the Thar desert and extends across the border of India and Pakistan.
- The Rann of Kutch is a unique ecosystem consisting of desert wetlands or seasonal salt marshes that remain flooded during the rainy season and turn into salt flats during the rest of the year.
Flora-
- Thorn scrub and grasslands like Acacia, Balanites roxburghii etc.
Fauna-
- Endangered Asiatic wild ass, one of the world's largest breeding colonies of the greater and lesser flamingos, Indian wolf, desert,fox, chinkara, nilgai, blackbuck etc.
Zone 4: The Semi-Arid
- Zone 4 is known as the Semi-Arid region.
- This region is located between the desert and the denser forests of the Western Ghats, making it a transitional zone.
- The Semi-Arid region is characterized by plain areas and the ancient Aravalli hill range.
- The topography of this region makes it an important area for biodiversity and conservation efforts.
This zone is divided into two biotic provinces –
- The Punjab plains.
- Gujarat Rajputana.
Fauna-
- The natural vegetation is thorn forest in the hills and grassland in the plain areas.
Fauna-
- Great Indian Bustard, Blackbuck, Chow Singha, Nilgai, and Gazelle, and carnivores- Lions etc.
Zone 5: The Western Ghats
- The Western Ghats are a range of mountains located along the west coast of peninsular India and are considered as one of the unique biological regions of the world.
- The diverse topography and varied climate of the Western Ghats have resulted in the creation of various habitats that support distinct plant and animal species.
- This region has been recognized as a UNESCO World Heritage Site and is among the world's hottest hotspots.
- Anamudi, situated in the southern Western Ghats, is the highest peak (2695 m) in the Indian Peninsula.
This biogeographic zone is divided into two biotic provinces-
- Malabar plains.
- The Western Ghat Mountains.
Flora-
- The flora of India includes various types of forests such as tropical evergreen forests, temperate moist deciduous forests, and temperate dry deciduous forests.
- Other types of vegetation in India include the Sholas, high altitude grasslands, and dry scrub vegetation.
- Shola forests, a type of tropical Montane forests, are only found in the valleys of south India that are separated by rolling grasslands, and they occur at higher elevations.
Fauna-
- Asian Elephant, Gaur, Tiger, lion-tailed Macaque, Nilgiri Tahr and Nilgiri Langur etc.
Zone 6: The Deccan Peninsula
- The Deccan Peninsula is a semi-arid region located in the rain shadow of the Western Ghats mountain range.
- It is India's largest biogeographic region, covering 42% of the country's total geographical area.
- The Deccan Peninsula is bordered to the north by the Vindhya and Satpura mountain ranges, to the east by the Eastern Ghats, and to the west by the Western Ghats.
- The Western and Eastern Ghats meet each other at the Nilgiri hills, surrounding the Deccan plateau.
- The region is home to several major rivers, including the Godavari, Krishna, and Cauvery, which flow from the Western Ghats towards the Bay of Bengal in the east.
This zone is divided into 6 biotic provinces-
- Central Highlands.
- Chotta Nagpur.
- Eastern Highlands.
- Central Plateau.
- Deccan South.
Flora-
- Mostly dry deciduous forests, with some dry thorn scrub towards west, and moist deciduous forests towards northeast.
- Example- Teak,Mahua,amla etc.
Fauna-
- Tiger, Chital, Sambar, Nilgai, Chowsingha, Elephant, Wild Buffalo, Hard Ground Swamp Deer etc.
Zone 7: The Gangetic Plain
- This is the largest unit of the Great Plain of India.
- The Gangetic plains are one of the most fertile areas of the world, formed by alluvium brought by Himalayan rivers, Ganges and Brahmaputra and their tributaries.
- This area is agricultural intensive area and have high population density.
- It accounts for 10.8 % of the total geographical area of India.
- Topographic uniformity can be seen in this area.
This zone is divided into two biotic provinces-
- Upper Gangetic Plains.
- Lower Gangetic Plains.
Flora-
- Teak, sal, shisham, mahua, khair etc.
Fauna-
- Nilgai, Blackbuck, and Chinkara, Sambar, and Chital etc.
Zone 8: The Coasts
- India boasts a coastline of 7516.6 km, comprising 6100 km of mainland coastline and 1197 km of Indian islands.
- The coastal plains are predominantly covered by fertile soils, which support the growth of various crops.
- Rice is the main crop grown in these areas, which are known for their agricultural productivity.
- Coconut trees are commonly found all along the Indian coast, adding to the region's biodiversity and natural beauty.
It is divided in three biotic provinces –
- West Coast- The backwaters are the characteristic features of this coast.
- The east coast plains, in contrast are broader due to depositional activities of the east-flowing rivers owing to the change in their base levels.
- East Coast- The backwaters are the characteristic features of this coast. The east coast plains, in contrast are broader due to depositional activities of the east-flowing rivers owing to the change in their base levels.
- Lakshadweep.
Flora-
- Mangroves, sunderban(in coastal states)and coral in Lakshadweep.
Fauna-
- Dolphin, Salt-Water Crocodile, turtle etc.
Zone 9: North-East India
- The North-East region of India is situated at the confluence of three regions - Indian, Indo-Malayan, and Indo-Chinese - making it a unique zone.
- The region is also the meeting place of the Himalaya and the Indian Peninsula, resulting in a high degree of biodiversity and endemism.
- North-East India is considered the richest biogeographic zone in India with respect to plant communities and endemism.
Flora-
- Tropical and sub-tropical evergreen forest, temperate rain forests, sub-alpine and alpine vegetation like- rhododendrons, bamboo, chir, oak, chestnut, maple etc.
- This area also have rich diversity of insectivorous plants ex- Nepenthes khasiana.
Fauna-
- Hornbill, Rhinoceros, Buffalo, Elephant, Swamp Deer, and Waterfowl, Hog Deer, Pygmy Hog, Hispid Hare etc.
Zone 10: The Islands
It is subdivided into two biogeographical provinces-
- Andaman and Nicobar Islands located in the Bay of Bengal.
- Lakshadweep islands located in the Arabian Sea.
Flora-
- This zone mostly consist of tropical and semi tropical vegetation.
Fauna-
- This region have large number of endemic species, some of the species are- Nicobar Macaque, Nicobar tree shrew, Narcodium Hornbill, Nicobar pigeon, Andaman wood pigeon, Nicobar parakeet, marine turtles etc.
Biodiversity hotspots
-
A biogeographical area with substantial levels of biodiversity that is at risk due to human habitation is commonly known as a "biodiversity hotspot.".
- This concept was developed by the British environmental expert Norman Myers in 1998.
- There are currently 36 recognized biodiversity hotspots (in 2022).
- Though these 36 hotspots together represent only 2.4% of the Earth’s land surface.
Criteria for Biodiversity Hotspots
To qualify as Biodiversity hotspot a region must meet two strict criteria-
1. Area must support at least 1,500 vascular plants (> 0.5% of the world’s total) as endemics. This indicates that area must have a high percentage of plant life found nowhere else on the planet. A hotspot is considered as irreplaceable.
2. Area must include 30% or less of its original natural vegetation which indicates that it must be threatened.
Out of these 36 hotspots, 4 hotspots are found in India
1. Sundalands –
- It includes Andaman & Nicobar Islands from India (and other are Indonesia, Malaysia, Singapore, Brunei, Philippines).
2. Western Ghats-
- It includes entire western Ghats from India and Other part include Sri Lanka.
3. Himalaya-
- It includes entire Himalayan part located in India and other part include Himalayas located in Pakistan, Tibet, Nepal, Bhutan, China and Myanmar.
4. Indo-Burma-
- It includes entire North-eastern India (except Assam and Andaman group of Islands) and Myanmar, Thailand, Vietnam, Laos, Cambodia and southern China.
The hottest hot spots
- Some hot spots are much richer than others in terms of their numbers of endemics known as the hottest hot spots.
Biodiversity cold spots
- These are the areas with a limited variety of living things, like plants, animals, fungi, and bacteria.
One liner Question and answers on Bio geography of India.
What is biogeography?
Biogeography is the study of distribution of biological species and ecosystems in geographical space and geological time.
How is a realm defined in biogeography?
A realm is typically defined by physical features such as climate, topography, and soil type, and it can span multiple countries or even continents.
What is a biome?
A biome refers to a naturally occurring community of plants and animals that exist in a particular habitat, such as a forest or tundra, on a large scale.
What is a biogeographic zone?
A biogeographic zone represents a geographical area having similar species of plants and animals, communities, ecosystems, and ecology.
What is a biotic province?
A biotic province refers to a geographic region that is inhabited by a distinct and unique set of organisms, which are separated from other regions by barriers that limit or prevent migration and movement of species.
How many biomes are there in India?
India has five biomes.
How many bio-geographic zones are there in India?
India is divided into 10 bio-geographic zones.
How many biotic provinces are there in India as per revised classification?
As per revised classification, there are a total of 27 biotic provinces in India.
Which realms are present in India?
India has two realms - the Himalayan region represented by Palearctic Realm and the rest of the sub-continent represented by Malayan Realm.
What are the five biomes of India?
The five biomes of India are tropical humid forests, tropical dry or deciduous forests (including monsoon forests), warm deserts and semi-deserts, coniferous forests, and alpine meadows.
What is a biodiversity hotspot?
A biodiversity hotspot is a biogeographical area with substantial levels of biodiversity that is at risk due to human habitation.
How many biodiversity hotspots are there in the world?
There are currently 36 recognized biodiversity hotspots in the world.
What are the criteria for a region to be considered a biodiversity hotspot?
A region must support at least 1,500 vascular plants as endemics and include 30% or less of its original natural vegetation to be considered a biodiversity hotspot.
How many biodiversity hotspots are found in India?
India has four biodiversity hotspots- Sundalands, Western Ghats, Himalaya, and Indo-Burma.
What are biodiversity cold spots?
Biodiversity cold spots are the areas with a limited variety of living things, like plants, animals, fungi, and bacteria.