Class
IX CHAPTER 5
Natural vegetation and wild life
Q.1
why forests are important for human beings?
A.1
1.Forest are renewable resources and plays a major role in enhancing the equality
of environment.
2.
They modify local climate, control soil erosion, regulate stream flow.
3.
They support a variety of industries, provide livelihood for many communities
and offer panoramic scenic view for recreation.
4.
It controls wind force and temperature and causes rainfall.
5.It
provides humus to soil and shelter to wildlife.
Q.2
Define an ecosystem.
A.2
Ecosystem is a system which comprises the physical environment and their
surroundings. All the plants and animals in an area are interdependent and
inter-related to each other in physical environment, thus, forming an
ecosystem. Ecosystem have evolved over a period of thousands of year.
Q.3
What factors are responsible for the distribution of plants and animals in
India?
A.3
India possess a great diversity of climate and physical conditions such as
favorable temperature, abundant sunlight, varied precipitation, soil condition
and different type of relief. As a result, India has a rich heritage of flora
and fauna.
Reasons
for which heritage of flora and fauna are rich in India are as follows:-
1. Climate
Temperature : Vegetation are mainly determined by temperature along with humidity in air,
precipitation and soil.
Photoperiod (Sunlight) : The Variation in duration of
sunlight at different places is due to differences in latitude, altitude,
season and duration of the day. Due to longer duration of sunlight, trees grow
faster in summer.
Precipitation: In India almost the entire rainfall is brought
in by the advancing South West Monsoon (June to September) and retreating north
east monsoon. Areas of heavy rainfall have more dense vegetation as compared to
other areas of less rainfall.
2. Relief
Land : Relief also affects vegetation, that I why our plains,
plateaus and mountains have different types of vegetation.
Soil: Changes in soil conditions have given rise to peculiar
type of vegetation. In many areas, such as mangrove, swamps and sandy and
coastal plains.
Q.4
What is bio-reserve ? Give two
examples.
A.4 A bio-reserve is a multipurpose
protected forest area where all type of
flora and fauna and pre-served in there in natural environment. Its main
features are :-
(i) In each biosphere, the one preserves the wild-life of
flora and fauna in their natural settings.
(ii) The surrounding area is utilized for research and
experimentation in forest and other production.
Nilgiri and Manas are eg of 2 biosphere reserves.
Q.5 Name different types of vegetation
found in india and describe the vegetation of high altitudes.
A.5 (a)
Tropical Evergreen Forests.
(i) These forests are restricted to
rainfall areas of the western ghats and the islands groups of Lakshadweep,
Andaman and Nicobar, upper parts of Assam and Tamil
Nadu coast.
(ii) They are at their best in areas having
more then 200cm of rainfall with a short dry
season. The trees reach great heights up to 60 meters or even above.
(iii) There is no definite time for trees to
shed their leave. As such, there forests appear green all the year round.
(iv) Some of the commercially important
trees of this forest are ebony, mahogany rosewood, rubber and cinchona.
(v) The common animal found in these
forests are elephants, monkey, lemur, deer and one-horned rhinoceros.
(b) Tropical deciduous
Forests.
(i) These are the most widespread forests
of India. They are also called the monsoon forests and spread over the rejoin receiving rain fall b/w 200
cm & 70 cm.
(ii) Trees of this forest – type shed their
leaves for about six to eight weeks in dry summer.
(iii) On the basis of the availability of
water, these forests are further divided into moist and dry deciduous.
(A) Moist- Deciduous Forest.
·
The moist – deciduous forests are found in areas receiving
rainfall b/w 200 $ 100 cm.
·
These forest exist, therefore, mostly in the eastern parts of
the country – northeastern states, along the foothills of Himalayas, Jharkhand, West Orissa, and Chhattisgarh and
the eastern slopes of the Western Ghats.
·
Teak is the most dominant species of the forest. Bamboos,
sal, shish am, sandalwood, khair, kusum Arjun, mulberry are other commercially
important species.
(B) Dry – Deciduous Forests.
·
The dry – deciduous forests are found in areas having
rainfall b/w 100 cm $ 70 cm.
·
These forests are found
in the rainier parts of the peninsular plateau and the plains of Bihar and Uttar Pradesh.
·
These are open sketches in which Teak, Sal Peepal, Neem grow.
·
In these forests, the common animal found are lion, tiger,
pig, deer and elephant. A huge variety of birds, lizards, snakes and tortoises.
(c ) The thorn forest and Scrubs
·
In region with less than 70 cm of rainfall, the natural vegetation consists of thorny
trees & bushes.
·
This type of vegetation is found in the north – western part of the country including semi – arid area of Gujrat,
Rajasthan, Madhya Pradesh & Haryana.
·
Acacias, palms, euphorbias and cacti are the mainplant species.
·
Trees are scattered and have long roots penetrating deep into
the soil in order to get moisture. The stem are succulent to conserve water.
Leaves are mostly thick & small to minimize evaporation.
·
In these forests, the common animals are rats, mice, rabbits,
fox, wolf, tiger, lion, wild ass, horses and camels.
(d) Montane forests
·
The wet temperate type forests are found between a height of
1000 to 2000m. Evergreen broad-leaf trees such as oaks and chestnuts
predominate.
·
Between 1500 to 3000m, Temperate forests containing
coniferous trees like pine, deodar, silver fir, spruce and cedar are found.
·
At higher elevations, temperature grasslands are common. At
high altitude generally more than 8600m above the sea-level temperate forests
and grasslands give way to alpine vegetation.
·
Silver fir, junipers, pines and birches are the common trees
of these forests. They get progressively stunned as they approach the
snow-line. Ultimately through shrubs and scrubs, they merge into the alpine
grasslands.
·
These are used extensively for grazing and shelter by nomadic
tribes like the Gujjars and the bakharwals.
·
At higher altitudes, mosses and lichens from parts of tundra
vegetation.
·
The common animals found in these forests 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 with
thick hair.
(e) Mangrove forests
·
The mangrove tidal
forests are found in the areas of coasts influenced by tides, mud and silt get
accumulated on such coasts.
·
Dense mangroves are the common varieties with roots of the
plants submerged under water.
·
The deltas of the Ganges, the Mahanadi, the Krishna, the
Godavari and the Kaveri are covered by such vegetation.
·
Palm, coconut, keora, agar also grow in some parts of the delta.
·
Royal Bengal Tiger is the famous animal in these forests.
Turtles, Crocodiles, Ghariyals and snakes are also found in these forests.
Q.6 Distinguish between flora and fauna.
A.6 Flora
·
The total vegetation or plant cover of a region is called
flora.
·
Plants are the procedures and they make their own food.
·
They do not move from one place to another.
·
It consists of flowering and non-flowering plants, forests,
grass, shrubs,etc.
·
India possess 47000 species of plants.
Fauna
·
The animal life of given area is called fauna.
·
Animals are the consumers. So they do not make their own
food.
·
They generally move from one place to another.
·
It consists of mammals, amphibians, birds, insects, warms,
etc.
·
India possess 89000 species of animals.
Q.7 Quite a few species of plants and animals
are endangered in India. Why?
A.7 a)
Due to excessive exploitation of the plants and the animals by man, the
ecosystem has been disturbed. About 1300 plant species are endangered and 20
species are extinct.
b)
Quite a few animals species are also endangered and have become extinct.
Main causes
a) Hunting by man for
commercial purposes.
b) Pollution due to chemical
and industrial waste, acid deposits.
c) Introduction of alien
species and reckless cutting of the forest to bring land under cultivation and
habitat also responsible for the imbalance.
Q.8 Mention the steps taken by (GOI) Government
of India to protect its flora and fauna.
A.8 To protect the flora and fauna of the
country, the government has taken many steps:-
a)
89 National parks, 490 wildlife sanctuaries and zoological gardens are set up
to take care of natural heritage.
b)
Project Tiger, Project Rhino, Project Great Indian Bustard and many other
eco-developmental projects have been introduced.
c)
Financial and technical assistance is provided to many botanical gardens by the
government since 1992.
d)
14 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
uttrakhand, gulf of mannar in tamil nadu and the nilgiris (Kerala, Karnataka
and Tamil Nadu) have been included in the world network of biosphere reserves.
