Overview Natural Vegetation: 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. It is termed as a virgin vegetation.
• term flora is used to denote plants of a particular region or period. species of animals are referred to as fauna.
• This huge diversity in flora and fauna kingdom is due to following factors:
Relief
• Land: Land affects natural vegetation directly and indirectly. fertile level is usually devoted to agriculture. undulating and rough terrains are areas where grassland and woodlands develop and gives shelter to a variety of wildlife.
• Soil: Different types of soils provide a basis for different types of vegetation. sandy soils of desert supports cactus and thorny bushes, while wet, marshy, deltaic soils supports mangroves and deltaic vegetation. soil at hill slopes has conical trees.
Climate
• Temperature: character and extent of vegetation are mainly determined by temperature along with humidity in air, precipitation and soil. fall in temperature affects vegetation and its growth.
• Photoperiod [Sunlight]: variation in duration of sunlight at different places is due to differences in latitude, altitude, season & duration of day. Due to longer duration of sunlight, trees grow faster in summer.
• Precipitation: Areas of heavy rainfall have more dense vegetation as compared to areas of less rainfall.
Types of Vegetation
• In India, following major types of vegetation are found:
(1) Tropical Evergreen Forests
(2) Tropical Deciduous Forests
(3) Thorn Forests and Scrubs
(4) Montane Forests
(5) Mangrove Forests
Tropical Evergreen Forests
• These forests are present in Western Ghats and island groups of Lakshadweep, Andaman & Nicobar, upper parts of Assam and Tamil Nadu coast.
• These forests grow best in areas having rainfall more than 200 cm with a short dry season.
• trees reach great heights up to 60 metres or even above. It has vegetation of all kinds i.e trees, shrubs & creepers giving it a multilayered structure.
• These forests appear green all year-round.
• Important trees of this forest are ebony, mahogany, rosewood, rubber & cinchona.
• Common animals found in these forests are elephant, monkey, lemur & deer.
Tropical Deciduous Forests
• These forests are known as monsoon forests. They are spread over region having rainfall between 200 cm and 70 cm. They shed their leaves for about 6 to 8 weeks in dry summer.
• In these forests, common animals found are lion, tiger, pig, deer & elephant.
• These forests are further divided into:
(1) Moist deciduous: These are found in areas having rainfall between 200 and 100 cm. Teak is most dominant species of this forest. Bamboos, sal, shisham, sandalwood, khair, kusum, arjun & mulberry are other commercially important species of plants.
(2) Dry deciduous: These are found in areas having rainfall between 100 cm and 70 cm. There are open stretches in which teak, sal, peepal & neem grow.
Montane Forests
• Montane forests are forests which are found in mountains.
• wet temperate type of forests are found between a height of 1000 and 2000 metres.
• At high altitudes, generally, more than 3,600 metres above sea level, temperate forests and grasslands give way to Alpine vegetation.
• Alpine grasslands are used for grazing.
• At higher altitudes, mosses & lichens form part of tundra vegetation.
• common animals found are Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear & rare red panda, sheep & goats.
Thorn Forests and Scrubs
• natural vegetation consists of thorny trees and bushes. This type of vegetation is found in north-western part of country, including semiarid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana.
• Trees are scattered and have long roots penetrating deep into soil to get moisture.
• stems are moist to conserve water.
• Leaves are mostly thick and small to minimise evaporation.
• Acacias, palms, euphorbias and cacti are main plant species.
• Common animals are rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses & camels.
Mangrove Forests
• Mangroves are trees that live along tropical coastlines, rooted in salty sediments, often underwater.
• mangrove tidal forests are found in areas of coasts influenced by tides. Mud and silt get accumulated on such coasts.
• Dense mangroves are common varieties with roots of plants submerged underwater.
• Sundari trees are found in Ganga-Brahmaputra delta and provide hard timber.
• Royal Bengal Tiger is a famous animal in these forests.
Wildlife
• India is rich in its fauna.
• Elephants are found in hot wet forests of Assam, Karnataka & Kerala.
• One-horned rhinoceroses are found in Assam and West Bengal.
• Rann of Kachchh is habitat for wild ass whereas Thar Desert is habitat for camels.
• natural habitat of Indian lion is Gir forest in Gujarat.
• Tigers are found in forests of Madhya Pradesh, Sundarbans of West Bengal and Himalayan region.
• Ladakh’s freezing high altitudes are home to yak, shaggy horned wild Ox Tibetan antelope, bharal [blue sheep], wild sheep, and kiang [Tibetan wild ass].
• In rivers, lakes & coastal areas, turtles, crocodiles and gharials are found.
• Peacocks, pheasants, ducks, parakeets, cranes & pigeons are some of birds inhabiting forests and wetlands of country.
Cause of Major Threat to flora and fauna
• Every species has an important role in ecosystem. Hence, conservation of flora and fauna is essential. About 1,300 plant species are endangered and 20 species are extinct. main causes of this major threat to nature are:
• Hunting for commercial purposes
(1) Pollution due to chemical and industrial waste.
(2) Rapidly cutting of forests for cultivation and habitation.
• Government Initiative to Protect Flora and Fauna
• government has taken many steps to protect flora and fauna of our country.
• 18 biosphere reserves have been set up in India to protect flora and fauna. 10 out of these have been included in world network of biosphere reserves.
• Financial and technical assistance has been provided to many botanical gardens by government since 1992.
• Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco-developmental projects have been introduced by government.
• 101 National Parks, 553 Wildlife Sanctuaries and Zoological gardens are set up to take care of natural heritage.