- India is one of the twelve mega biodiversity countries of the world. With about 47,000 plant species, India occupies tenth place in the world and fourth in Asia in plant diversity.
- There are about 15,000 flowering plants in India which account for 6 percent of the world’s total number of flowering plants. The country has many non-flowering plants such as ferns, algae, and fungi.
- India also has 89,000 species of animals as well as a rich variety of fish in its fresh and marine waters.
- Refers to a plant community that has grown naturally without human aid and has been left undisturbed by humans for a long time. This is termed as virgin vegetation.
- Thus, cultivated crops, and fruits, orchards are a part of vegetation but not natural vegetation.
Distribution of Various Types of Vegetation over India
- India’s natural vegetation has undergone many changes due to several factors such as the growing demand for cultivated land, development of industries and mining, Urbanisation and over-grazing of pastures.
- The vegetation cover of India in large parts is more natural in the real sense. Except in some inaccessible regions like the Himalayas, the hilly region of central India, and the marusthali, the vegetation of most of the areas has been modified at some places or replaced or degraded by human occupancy.
- Flora: The term flora is used to denote plants of a particular region or period.
Fauna: The species of animals are referred to as fauna.
Try yourself:Which term is used for the original plant cover of an area which has grown naturally?
Natural vegetation refers to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time. This is termed as a virgin vegetation.
Factors which affect the diversity of flora and fauna are as following:
- Land affects natural vegetation directly and indirectly. The nature of land influences the type of vegetation.
- The fertile level is generally devoted to agriculture.
- The undulating and rough terrains are areas where grassland and woodlands develop and give shelter to a variety of wildlife.
- Different types of soil provide basis for different types of vegetation.
- The sandy soils of the desert support cactus and thorny bushes.
- The wet, marshy, deltaic soil support mangroves and deltaic vegetation.
- The hill slopes with some depth of soil have conical trees.
- The character and extent of vegetation are mainly determined by temperature along with humidity in the air, precipitation and soil.
- On the slopes of the Himalayas and the hills of the Peninsula above the height of 915 meters, low temperature affects the types of vegetation and its growth. Temperature changes it from tropical, temperature and alpine.
- The variation in Sunlight received at different places is due to the difference in latitude, altitude, season, and duration of the day.
- Adequate sunlight in summer causes trees to grow faster.
Precipitation determines the density of vegetation. Areas of heavy rainfall have more dense vegetation as compared to other areas of less rainfall.
Try yourself:The character and extent of vegetation are mainly determined by which of the climatic factor?
The character and extent of vegetation are mainly determined by temperature, humidity and precipitation. Extent of vegetation is mainly determined by temperature along with humidity in the air, precipitation and soil.
Importance of Forests for Human life
- Forests are renewable resources and play a major role in enhancing the quality of the environment.
- They modify the local climate, control soil erosion, regulate stream flow, support a variety of industries, provide a livelihood for many communities and offer panoramic or scenic views for recreation. It controls wind force and temperature and causes rainfall. It provides humus to the soil and shelter to the wildlife.
Ecosystem and Biomes
It is an integrated unit consisting of the community of living organisms and the physical environment in a particular area. Plants occur in distinct groups of communities in areas having similar climatic conditions. The nature of the plants in an area, to a large extent, determines the animal life in that area.Difference between Ecosystem and Biome
A very large ecosystem on land having distinct types of vegetation and animal life is called a biome. Biomes include both flora and fauna, but it is mainly the plant formations that are used as the basis of their grouping.
On the basis of the order of availability of soil, water and heat, the world is divided into five principal biomes:
Types of Vegetation
- They are at their best in areas having more than 200 cm of rainfall with a short dry season.
- In these forests, trees grow up to 60 m & above.
Tropical Evergreen Forests
- These forests yield hardwood trees.
- These forests are found in rainy parts of Western Ghats, Assam, West Bengal, Lakshadweep, and Andaman & Nicobar Islands.
- Ebony, Mahogany, Rosewood, Rubber, and Cinchona are some of the important trees.
- In these forests, a large number of plant species are found in one place. It creates difficulty in their commercial exploitation.
- Elephants, monkeys, Lemur, and Deer are some common animals found in these forests.
Tropical Deciduous Forests
- These are the most widespread forests of India.
- They are also called the monsoon forests and spread over the region, receiving rainfall between 200 cm and 70 cm.
- Trees of this forest type shed their leaves for about six to eight weeks in dry summer.
On the basis of the availability of water, these forests are further divided into:
(a) Moist Deciduous
- These forests are found in areas of 100 cm to 200 cm of rainfall.
- Due to a long dry season, the trees shed their leaves during the dry season.
- Shisham, Bamboos, Sandalwood, Khair, Kusum, Arjun, Mulberry, and Sal are the common trees found in these forests.
- These forests cover a vast area of the country. Northeastern states, along the foothills of the Himalayas, Jharkhand, West Orissa, and Chhattisgarh, and on the Eastern slopes of the Western Ghats.
(b) Dry Deciduous
- These are found in areas having rainfall between 70 cm to 100 cm.
- These are found in the rainier part of the peninsular plateau and the plains of Bihar and U.P.
- These are open stretches in which Teak, Sal, Peepal, Neem grow.
- Most of these forests have been cleared for cultivation.
- In these forests, the common animals found are lions, tigers, pigs, deer and elephants. A huge variety of birds, lizards, snakes, and tortoises are also found here.
Thorn Forests and Shrubs
- Tropical thorn forests occur in areas that receive rainfall less than 70 cm.
- These consist of a variety of grasses and shrubs.
Thorn Forest and Shrubs
- It includes semi-arid areas of southwest Punjab, Haryana, Rajasthan, Gujarat, Madhya Pradesh, and Uttar Pradesh.
- In these forests, plants remain leafless for the most part of the year and give an expression of shrub vegetation.
- Important species found are babul, Kher and wild Date palm, Kikar, Neem, Khejri, Palas, etc.
In mountainous areas, the decrease in temperature with increasing altitude leads to the corresponding change in natural vegetation:
- The wet temperate type of forest is between a height of 1000 and 2000 meters. Evergreen broad-leaf trees such as oaks and chestnuts predominate.
- Between 1500 and 3000 meters, temperate forests containing coniferous trees like pine, deodar, silver fir, spruce, and cedar, are found. These forests cover mostly the southern slopes of the Himalayas, places having high altitudes in southern and northeast India. At higher elevations, temperate grasslands are common.
Distribution of Mountain Forest
- At high altitudes, generally more than 3600 meters above sea level, temperate forests and grasslands give way to the Alpine vegetation. Silver fir, junipers, pines, and birches are the common trees of these forests.
- Above Alpine vegetation, Alpine grasslands are found. These are used extensively for grazing by nomadic tribes like the Gujjars and the Bakarwals. At higher altitudes, mosses and lichens form part of tundra vegetation.
- The common animals found in these frosts are Kashmir stag, spotted dear, wild sheep, jackrabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, dear and rare red panda, sheep, and goats with thick hair.
Try yourself:Why is the southern slopes in Himalayan region covered with thick vegetation?
The southern slopes in Himalayan region covered with thick vegetation as compared to northern slopes of the same hills on account of more exposure to sunlight, more precipitation, and less exposure to colder wind.
- These are found in the areas which are under the influence of tides having accumulated mud and silt.
- Dense mangroves are the common varieties with roots of plants submerged underwater.
- These forests are found in the deltas of Ganga, Mahanadi, Godavari, and Kaveri.
- The most important tree is the Sundari tree, after which the Sunderbans are named.
- The tree provides hard, durable, and strong wood, which is used for building boats and boxes.
- Royal Bengal Tiger is the famous animal in these forests. Turtles, crocodiles, gharials, and snakes are also found in these forests.
Try yourself:Ebony, mahogany and rosewood trees are grown in which type of the forests?
The commercially important trees of the tropical rain forest are ebony, mahogany, rosewood, rubber and cinchona.
- Forests have an intricate interrelationship with life and the environment. These provide numerous direct and indirect advantages to our economy and society.
- Hence, the conservation of forests is of vital importance to the survival and prosperity of humankind.
- Accordingly, the Government of India proposed to have a nationwide forest conservation policy and adopted a forest policy in 1952, which was further modified in 1988.
- According to the new forest policy, the Government would emphasize sustainable forest management in order to conserve and expand forest reserve on the one hand and to meet the needs of local people on the other.
- The forest policy aimed at:
(i) Bringing 33 percent of the geographical areas under forest cover.
(ii) Maintaining environmental stability and restoring forests where the ecological balance was disturbed.
(iii) Conserving the natural heritage of the country, its biological diversity, and genetic pool.
(iv) Checks soil erosion, an extension of the desert lands, and reduction of floods and droughts.
(v) Increasing the forest cover through social forestry and afforestation on degraded land.
(vi) Increasing the productivity of forests to make timber, fuel, fodder, and food available to rural population dependant on forests, and encourage the substitution of wood.
(vii) Creating a massive people’s movement involving women to encourage the planting of trees, stop falling of trees, and thus, reduce pressure on the existing forest.
- The wildlife of India is a great natural heritage. It is estimated that about 4-5 percent of all known plant and animal species on the earth are found in India.
- The main reason for this remarkable diversity of life forms is the great diversity of the ecosystem, which this country has preserved and supported through the ages.
- India has more than 1200 species of birds, 2500 species of fish, and between 5 to 8 percent of the world’s amphibians, reptiles, and mammals.
- India is the only country in the world that has both tigers and lions. The Himalayas have a large range of animals that survive the bitter cold.
- Every species of animal has a role to play in the ecosystem; hence conservation is essential.
- Hunting and pollution are causing threats to animal species. To protect flora and fauna of the country, the government has taken many steps.
- Eighteen biosphere reserves have been set up in the country to protect flora and fauna. 89 national Parks, 49 Wildlife Sanctuaries, and Zoological Gardens are set up to take care of natural heritage.
- Over the years, their habitat has been disturbed by human activities and as a result, their numbers have dwindled significantly. There are certain species that are on the brink of extinction.
Some of the important reasons for the declining wildlife are as follows:
- Industrial and technological advancement brought about a rapid increase in the exploitation of forest resources.
- More and more lands were cleared for agriculture, human settlement, roads, mining, reservoirs, etc.
- Pressure on forests mounted due to lopping for fodder and fuelwood and removal of small timber by the local people.
- Grazing by domestic cattle caused an adverse effect on wildlife and its habitat.
- Hunting was taken up as a sport by the elite and hundreds of wild animals were killed in a single hunt. Now commercial poaching is rampant.
- Incidence of forest fires.
Wildlife Conservation in India
- Eighteen biosphere reserves have been set up in the country to protect flora and fauna.
- Four out of these, the Sunderbans in the West Bengal, Nanda Devi in Uttarakhand, the Gulf of Mannar in Tamil Nadu, and the Nilgiris (Kerala, Karnataka, and Tamil Nadu) have been included in the world network of Biosphere reserves.
- Financial and technical assistance is provided to many Botanical Gardens by the government projects that have been introduced.
- 89 National Parks, 492 Wildlife Sanctuaries, and Zoological gardens are set up to take care of Natural heritage.
Try yourself:Which one of the following bio-reserves of India is not included in the world network of bio-reserve?
A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas that are internationally recognised within the framework of UNESCO’s Man and Biosphere programme. There are 15 biosphere reserves in India. Out of these four biospheres have been included in the world network of Biosphere reserves. These four biosphere reserves are:
(1) Sunderbans in West Bengal
(2) Nanda Devi in Uttarakhand
(3) Gulf of Mannar in Tamilnadu
(4) Nilgiris in Kerala, Karnataka, and Tamil Nadu.
- A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas that are internationally recognized within the framework of UNESCO’s Man and Biosphere (MAB) Programme.
- The Biosphere Reserve aims at achieving the three objectives:
(i) Conservation of biodiversity and ecosystem.
(ii) Association of the environment with development.
(iii) International network for research and monitoring.
There are 18 Biosphere Reserves in India, out of which 11 Biosphere Reserves have been recognized by the UNESCO on World Network of Biosphere Reserves, namely:
- Nilgiri, 2000
- Sunderbans, 2001
- Gulf of Mannar, 2001
- Nanda Devi, 2004
- Nokrek, 2009
- Pachmarhi, 2009
- Similipal, 2009
- Achanakmar - Amarkantak, 2012
- Great Nicobar, 2013
- Agasthyamalai, 2016
- Kangchenjunga, 2018
List of Biosphere Reserve
1. Nilgiri Biosphere Reserve
- Total Geographical Area (km2): 5,520
- Location (states): Part of Wayanad, Nagarhole, Bandipur and Madumalai, Nilambur, Silent Valley, and Siruvani hills (Tamil Nadu, Kerala and Karnataka).
2. Nanda Devi Biosphere Reserve
- Total Geographical Area (km2): 5860.69
- Location (states): Part of Chamoli, Pithoragarh, and Bageshwar districts (Uttarakhand).
3. Nokrek Biosphere Reserve
- Total Geographical Area (km2): 820
- Location (states): Part of Garo Hills (Meghalaya).
4. Manas Biosphere Reserve
- Total Geographical Area (km2): 2,837
- Location (states): Part of Kokrajhar, Bongaigaon, Barrette, Nalbari, Kamru and Darrang districts (Assam).
5. Sunderbans Biosphere Reserve
- Total Geographical Area (km2): 9,630
- Location (states): Part of the delta of Ganges and Brahmaputra river system (West Bengal).
6. Gulf of Mannar Biosphere Reserve
- Total Geographical Area (km2): 10,500
- Location (states): Indian part of Gulf of Mannar between India and Sri Lanka(Tamil Nadu).
7. Great Nicobar Biosphere Reserve
- Total Geographical Area (km2): 885
- Location (states): Southernmost islands of the Andaman and Nicobar(A & N Islands).
8. Similipal Biosphere Reserve
- Total Geographical Area (km2): 4,374
- Location (states): Part of Mayurbhanj district (Orissa).
9. Dibru-Saikhowa Biosphere Reserve
- Total Geographical Area (km2): 765
- Location (states): Part of Dibrugarh and Tinsukia districts (Assam).
10. Dihang Dibang Biosphere Reserve
- Total Geographical Area (km2): 5,111.50
- Location (states): Part of Siang and Debang valley in Arunachal Pradesh.
11. Kanchenjunga Biosphere Reserve
- Total Geographical Area (km2): 2,619.92
- Location (states): Part of North and West Sikkim.
12. Pachmarhi Biosphere Reserve
- Total Geographical Area (km2): 4,926.28
- Location (states): Part of Betul, Hoshangabad, and Chindwara districts of Madhya Pradesh.
13. Agasthyamalai Biosphere Reserve
- Total Geographical Area (km2): 3500.36
- Location (states): Agasthyamalai Hills in Kerala.
14. Achanakmar-Amarkantak Biosphere Reserve
- Total Geographical Area (km2): 3,835.51
- Location (states): Parts of Anupur and Dindori district of MP and parts of Bilaspur district of Chhattisgarh.
15. Kachchh Biosphere Reserve
- Total Geographical Area (km2): 12,454
- Location (states): Part of Kachchh, Rajkot, Surendra Nagar and Patan Civil Districts of Gujarat State.
16. Cold Desert Biosphere Reserve
- Total Geographical Area (km2): 7770
- Location (states): Pin Valley National Park and surroundings; Chandratal and Sarchu&Kibber Wildlife Sanctuary in Himachal Pradesh.
17. Seshachalam Hills Biosphere Reserve
- Total Geographical Area (km2): 4755.997
- Location (states): Seshachalam Hill Ranges covering parts of Chittoor and Kadapa districts of Andhra Pradesh.
18. Panna Biosphere Reserve
- Total Geographical Area (km2): 2998.98
- Location (states): Part of Panna and Chhattarpur districts in Madhya Pradesh.
Try yourself:In which of the following state is the Simlipal bio-reserve located?