- India is one of the twelve mega bio-diversity countries of the world. India occupies 10th place in the world with about 47,000 plant species and 4th in Asia in plant diversity.
- 15,000 flowering plants in India constitutes 6 percent in the world’s total number of flowering plants. India also has approximately 90,000 species of animals as well as a rich variety of fish in its fresh and marine waters.
- A plant community which has grown naturally without human aid is called Natural vegetation.
- Natural vegetation that has been left undisturbed by humans for a long time is called virgin vegetation.
- Flora is used to denote plants of a particular region or period and fauna is species of animals of a particular region or period. Flora and fauna kingdom constitute biodiversity of a particular region or period.
- Relief, Climate and Ecosystem are three factors for biodiversity.
- Land: The nature of land influences the type of vegetation. Fertile lands supports agriculture while undulating and rough terrains have grassland and woodlands which give shelter to a variety of wild life.
- Soil: Different types of soils provide basis for different types of vegetation. The sandy soils of the desert support cactus and thorny bushes while wet, marshy, deltaic soils support mangroves and deltaic vegetation. The hill slopes with some depth of soil have conical trees.
- Temperature: The character and extent of vegetation are mainly determined by temperature along with humidity in the air, precipitation and soil.
- Sunlight: Due to differences in latitude, altitude, season and duration of the day there is variation in duration of sunlight.
- Precipitation (Rains): Areas of heavy rainfall have more dense vegetation as compared to other areas of less rainfall. In India, almost the entire rainfall is brought in by the advancing southwest monsoon (June to September) and retreating northeast monsoons.
- All the plants and animals in an area are interdependent and interrelated to each other in their physical environment, thus, forming an ecosystem.
- A very large ecosystem on land having distinct types of vegetation and animal life is called a biome.
Importance of Forests:
- These are renewable resources and play a major role in enhancing the quality of environment.
- They modify local climate, control soil erosion, regulate stream flow, support a variety of industries, provide livelihood for many communities and offer panoramic or scenic view for recreation.
- It controls wind force and temperature and causes rainfall. It provides humus to the soil and shelter to the wildlife.
Natural vegetation in India 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.
Types of Vegetation
Types of vegetation may be identified in our country are:
- Tropical Evergreen Forests
- Tropical Deciduous Forests
- Tropical Thorn Forests and Scrubs
- Montane Forests
- Mangrove Forests
Tropical Evergreen Forests:
- These forests are restricted to heavy rainfall areas of the Western Ghats and the island groups of Lakshadweep, Andaman and Nicobar, upper parts of Assam and Tamil Nadu coast.
- They grow in an area of 200 cm of rainfall with a short dry season.
- The trees reach great heights up to 60 metres or even above.
- These forests have rich vegetation of all kinds – trees, shrubs, and creepers which give it a multilayered structure since the region is warm and wet throughout the year.
- The forests appear green all the year round because there is no definite time for trees to shed their leaves.
- Commercially important trees of this forest are ebony, mahogany, rosewood, rubber and cinchona.
- Common animals found in these forests are elephants, monkey, lemur and deer. Plenty of birds, bats, sloth, scorpions and snails are also found.
Tropical Deciduous Forests
- Most widespread forest in India.
- These 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.
- These forests are further divided into two types: Moist and Dry deciduous.
- Moist deciduous: Found in areas receiving rainfall between 200 and 100 cm. Present mostly in the eastern part 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. Teak is the most dominant species of this forest. Commercially important species are Bamboos, sal, shisham, sandalwood, khair, kusum, arjun, mulberry.
- Dry deciduous: Found in areas having rainfall between 100 cm and 70 cm. Present in the rainier parts of the peninsular plateau and the plains of Bihar and Uttar Pradesh. There are open stretches in which Teak, Sal, Peepal, Neem grow. A large part of this region has been cleared for cultivation and some parts are used for grazing. Common animals found are lion, tiger, pig, deer and elephant also huge variety of birds, lizards, snakes, and tortoises are found here.
Tropical thorn forests and Scrubs
- These are found in the region of with less than 70 cm of rainfall.
- The natural vegetation consists of thorny trees and bushes. Acacias, palms, euphorbias and cacti are the main plant species.
- Trees are scattered and have long roots penetrating deep into the soil to get moisture. The stems are succulent to conserve water. Leaves are mostly thick and small to minimize evaporation.
- Common animals are rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses and camels.
- Montane forests have a succession of natural vegetation belts in the same order as we see from the tropical to the Tundra region.
- Between a height of 1000 and 2000 metres, wet temperate type of forests containing evergreen broad-leaf trees such as oaks and chestnuts are predominate.
- Between 1500 and 3000 metres, temperate forests containing coniferous trees like pine, deodar, silver fir, spruce and cedar, are found.
- At higher elevations, temperate grasslands are common.
- At high altitudes, generally more than 3,600 metres above sea-level, alpine vegetation found which have silver fir, junipers, pines and birches trees common.
- Near snow line, shrubs and scrubs, they merge into the Alpine grasslands which 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 forests are Kashmir stag, spotted dear, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, Shaggy horn wild ibex, bear and rare red panda, sheep and goats with thick hair.
- These forests are found in the areas of coasts influenced by tides where mud and silt get accumulated.
- Dense mangroves are the common varieties with roots of the plants submerged under water. These are deltas of the Ganga, the Mahanadi, the Krishna, the Godavari and the Kaveri
- In the Ganga- Brahamaputra delta, sundari trees are found, which provide durable hard timber.
- Palm, coconut, keora, agar, also grow in some parts of the delta.
- Royal Bengal Tiger is the famous animal also turtles, crocodiles, gharials and snakes are found in these forests.
- India has about 2,000 species of birds which constitute 13% of the world’s total. There are 2,546 species of fish, which account for nearly 12% of the world’s stock. It also shares between 5 and 8 percent of the world’s amphibians, reptiles and mammals.
- Elephants are found in the hot wet forests of Assam, Karnataka and Kerala.
- One-horned rhinoceroses live in swampy and marshy lands of Assam and West Bengal.
- Rann of Kachchh is habitat of wild ass and camels are found in Thar desert.
- Indian bison, nilgai (blue bull), chousingha (four horned antelope), gazel and different species of deer are some other animals found in India.
- India is the only country in the world that has both tigers and lions. Gir forest in Gujrat is the natural habitat of lion whereas Tigers are found in the forests of Madhya Pradesh, the Sundarbans of West Bengal and the Himalayan region.
- The Himalayas harbour a hardy range of animals, which survive in extreme cold.
- Ladakh’s freezing high altitudes are a home to yak, the shaggy horned wild ox weighing around one tonne, the Tibetan antelope, the bharal (blue sheep), wild sheep, and the kiang (Tibetan wild ass). The ibex, bear, snow-leopard and very rare red panda are found in certain parts.
- In the rivers, lakes and coastal areas, turtles, crocodiles and gharials are found.
- Birds like Peacocks, pheasants, ducks, parakeets, cranes and pigeons are some of the birds inhabiting the forests and wetlands of the country.
Conservation of Flora and Fauna
The excessive exploitation of the plants and animal resources by human beings, disturbed the ecosystem. About 1,300 plant species are endangered and 20 species are extinct also few animals are endangered and some have become extinct.
Causes of this threats are:
- Hunting by greedy hunters for commercial purposes.
- Pollution due to chemical and industrial waste and acid deposits
- Introduction of alien species
- Reckless cutting of the forests to bring land under cultivation and inhabitation.
Governmental steps to protect flora and fauna of country are:
- Fourteen biosphere reserves have been set up in the country to protect flora and fauna.
- Financial and technical assistance is provided to many Botanical Gardens by the government since 1992.
- Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco- developmental projects have been introduced.
- 89 National Parks, 490 Wildlife sanctuaries and Zoological gardens are set up to take care of Natural heritage.
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 Biosphese reserves.
List of fourteen bio-reserves in India are:
- Sunderbans (West Bengal)
- Simlipal (Odhisha)
- Gulf of Mannar (Tamil Nadu)
- Dihang-Dibang (Arunachal Pradesh)
- The Nilgiris in South India (in the states of Tamil Nadu, Karnataka and Kerala)
- Dibru Saikhowa (Arunachal Pradesh)
- Nanda Devi (Uttarakhand)
- Agasthyamalai (Kerala and Tamil Nadu)
- Nokrek (Meghalaya)
- Kanchenjunga (Sikkim)
- Great Nicobar (Bay of Bengal)
- Pachmari (Madhya Pradesh)
- Manas (Assam)
- Achanakmar-Amarkantak (Chhattisgarh)