Natural Vegetation and Wildlife Geography Chapter-5 Class-9 • Natural vegetation refers to a plant community, which has grown naturally wi...
Natural Vegetation and Wildlife
Geography
Chapter-5 Class-9
• 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 virgin vegetation.
• The term flora is used to denote plants of a particular region or period. The species of animals are referred to as fauna.
Flora and fauna kingdom constitute biodiversity of a particular region or period.
Virgin vegetation are of two types
Endemic species Those plant species which originated from the country, are termed as endemic species.
Exotic species Those plant species which originated outside the country are termed as exotic species.
# Factors Affecting Diversity (Relief, Climate and Ecosystem)
० Relief
i) 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.
ii) 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.
० Climate
i) Temperature
The character and extent of vegetation are mainly determined by temperature along with humidity in the air, precipitation and soil. The fall in the temperature affects the vegetation and its growth.
ii) Photoperiod (Sunlight)
The variation in the duration of sunlight at different places is due to differences in latitude, altitude, season and duration of the day. Due to the longer duration of sunlight, trees grow faster in summer.
iii) Precipitation
Areas of heavy rainfall have more dense vegetation as compared to areas of less rainfall.
०Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the non-living, physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.
All the plants and animals in an area are interdependent on each other in their physical environment and form.
• Biome is a major community of plants and animals having similar life forms existing under similar environmental conditions.
Types of Vegetation
The major types of vegetation found in India are :
i) Tropical Evergreen Forests
• present in the Western Ghats and the island groups of Lakshadweep, Andaman and Nicobar, upper parts of Assam and Tamil Nadu coast.
• Grow best in areas having rainfall more than 200 cm with a short dry season.
• It has the vegetation of all kinds i.e trees, shrubs and creepers giving it a multilayered structure.
The trees reach great heights up to 60 metres or even above.
• These forests appear green all the year-round (Evergreen forest)
• Important trees are ebony, mahogany, rosewood, rubber and cinchona.
• Common animals are elephant, monkey, lemur and deer.
ii) Tropical Deciduous Forests (also called monsoon forests)
• spread over the region having rainfall between 200 cm and 70 cm.
• mostly found in northeastern states, along the foothills of the Himalayas, Jharkhand, West Odisha and Chhattisgarh,and on the eastern slopes of the Western Ghats.
• Trees shed their leaves about 6 to 8 weeks in the dry summer.
• The common animals are lion, tiger, pig, deer and elephant. A huge variety of birds, lizards, snakes and tortoises are also found here.
These forests are further divided into:
Moist deciduous: rainfall between 200 and 100 cm.
Teak, Bamboos, sal, shisham, sandalwood, khair, kusum, arjun and mulberry.
Dry deciduous:rainfall between 100 cm and 70 cm. teak, sal, peepal and neem
iii) Tropical Thorn Forests and Scrubs
• found in the north-western part of the country, including semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana.
• Trees are scattered and have long roots penetrating deep into the soil to get moisture.The stems are moist to conserve water.Leaves are mostly thick and small to minimise evaporation.
• Main plants are acacias, palms, euphorbias and cacti
• Common animals are rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses and camels.
iv) Montane Forests
• Found in the mountains.
• The wet temperate type of forests are found between a height of 1000 and 2000 metres.oaks and chestnuts
• Between 1500 and 3000 metres, temperate forests containing coniferous trees, like pine, deodar, silver fir,spruce and cedar found.
• At high altitudes, generally, more than 3,600 metres above the sea level, temperate forests and grasslands give way to the Alpine vegetation (Silver fir, junipers, pines and birches ).
• Alpine grasslands are used 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 are Kashmir stag, spotted deer, wild sheep, jack rabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear and rare red panda, sheep and goats.
v) Mangrove Forests
• Mangroves are trees that live along tropical coastlines, rooted in salty sediments, often underwater.
• The mangrove tidal forests are found in the areas of coasts influenced by tides. Mud and silt get accumulated on such coasts.(delta of Ganga, Brahmaputra, Mahanadi, Godavari, Krishna and Kaveri)
• Dense mangroves are the common varieties with roots of the plants submerged underwater.
• Sundari trees are found in Ganga-Brahmaputra delta and provide hard timber.Other trees are palm, coconut, keora and agar.
• Royal Bengal Tiger is a famous animal in these forests.snakes, turtles, gharials and crocodiles are also found.
Wildlife
India is rich in its fauna same as flora.
Elephants- hot wet forests of Assam, Karnataka and Kerala
One-horned rhinoceroses - Assam and West Bengal
Wild ass - Rann of Kachchh
Camels - Thar Desert
Indian lion - Gir forest in Gujarat.
Tigers - Madhya Pradesh, the Sundarbans of West Bengal and the Himalayan region.
Ladakh is home to yak, the shaggy horned wild ox, the Tibetan antelope, the bharal (blue sheep), wild sheep, and the kiang (Tibetan wild ass).
In the rivers, lakes and coastal areas, turtles, crocodiles and gharials are found.
Peacocks, pheasants, ducks, parakeets, cranes and pigeons are some of the birds inhabiting the forests and wetlands of the country.
Cause of Major Threat to flora and fauna
Our crops consist of edible plants from a bio-diverse environment. Many medicinal plants are also used by us. The animals were selected from large stock provided by nature as milch animal. They also provided us draught power, transportation, meat, eggs.
The fish provide nutritive food. Many insects help in pollination of crops and fruit trees.
Every species has an important role in the ecosystem. Hence, conservation of flora and fauna is essential. About 1,300 plant species are endangered and 20 species are extinct.
The main causes of this major threat to nature are:
• Hunting for commercial purposes ,
• Pollution due to chemical and industrial waste ,
• Rapidly cutting of the forests for cultivation and habitation.
Government Initiative to Protect Flora and Fauna
i) The government has taken many steps to protect the 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 the world network of biosphere reserves.
ii) Financial and technical assistance has been provided to many botanical gardens by the government since 1992.
iii) Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco-developmental projects have been introduced by the government.
iv) 103 National Parks, 535 Wildlife Sanctuaries and Zoological gardens are set up to take care of natural heritage.
v) Wildlife Protection Act was implemented in 1972 in India.
* According to India State of Forest Report (SFR) 2015, the forest cover in India is 21.34% which was 21.05% in the year 2011.
Migratory Birds
Some of the wetlands of India are popular with migratory birds. During winter, birds, such as Siberian Crane, come in large numbers. One such place favourable with birds is the Rann of Kachchh. At a place where the desert merges with the sea, flamingo with their brilliant pink plumage come in thousands to build nest mounds from the salty mud and raise their young ones.
Eighteen Bio-reserves of India
i) Sundarbans
ii) Simlipal
iii) Gulf of Mannar
iv) Dihang-Dibang
v) Nilgiri
vi) Dibru Saikhowa
vii) Nanda Devi
Viii) Agasthyamalai
ix) Nokrek
x) Kangchendzonga
xi) Great Nicobar
xii) Pachmarhi
xiii) Manas
xiv) Achanakmar-Amarkantak
xv) Kachchh
xvi) Cold Desert
xvii) Seshachalam
xviii) Panna
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