Transcript Pranav_SessionIV_28Dec2006

Done by:
Pranav B, IX A,
Sri Vani Education Centre,
Hanumavana, Machohalli,
Bengalooru.
Biosphere is the outermost part
of the Earth where living
organisms occur. It consists of
three parts, i.e., Lithosphere
(Land), Hydrosphere (Water)
and Atmosphere (Air).
Biosphere is said to be made up of many
Ecosystems. Ecosystems are parts of the
Biosphere where living and non-living
organisms live together, interact with
each other and are dependant on each
other.
The living part of an ecosystem is called
as the biotic component while the abiotic
components constitute the non-living part.
The biotic components of an ecosystem can be
further categorized into Flora and Fauna.
Flora refers to the plant life growing in a
particular place or at a particular time.
Fauna is the collective term used for the animal
life growing in a particular place or at a
particular time.
Flora and fauna are interdependent to an
extent that they cannot be separated from one
another without causing extensive damage to
the other.
Ex: In a pond ecosystem, the hydrillas
and the plant cover are the flora while
the fish, frog, and other animals
represent the fauna
Insects are invertebrates and belong
to the Phylum Arthropoda.
They are one of the most successful
group of organisms in the world
containing more than 925,000 types
of species.
Insectus in Latin means “cut into
sections”.
The study of insects in called
Entomology.
They help in pollination of trees and in seed dispersal, provide us,
honey, wax, silk, etc., check the growth rate of other insects, and
are helpful to us in a number of ways.
Amphibians are a class of animals
who live both on land and in water.
On land, they breathe through their
lungs while they breathe through
their skin underwater. As they
breathe through their skins, they are
very sensitive.
There are nearly 6,000 species of
amphibians.
Amphibia, in Greek, means “Both type
of life”.
They consume mostly insects and thus help in keeping a check on the
number of insects.
Reptiles are cold-blooded and
belong to the Phylum Vertebrata.
They are found nearly
everywhere except in Antarctica.
There are approximately 8,000
existing species of reptiles.
The study of reptiles (and
amphibians) is called Herpetology.
Reptilia in Latin means “Creeping”.
They help farmers by checking the number of mice in their sheds
and fields. Some of them reduce the number of insects.
Birds are warm-blooded animals who
belong to the Phylum Vertebrata.
There are about 8,800 – 10,200
living species of birds. Sadly nearly
150 species of birds have become
extinct.
The earliest known species of birds
are Archaeopteryx lithographica.
The study of Birds is called
Ornithology.
They are a major source of food for humans. They also help in seed
dispersal. In earlier times, they were used to deliver messages. They help in
keeping a check on other animals and insects.
Mammals are warm-blooded
animals who belong to the
Phylum Vertebrata.
They are characterized by
production of milk for their
young, presence of hair or fur,
and many more.
The study of mammals is called
Mammalogy.
There are nearly 5,500 species
of mammals.
They provide milk, fur, meat
and many more things to us.
The major problem faced by Fauna all
over the world is Extinction.
Man has recklessly modified the
environment to an extent that the fine
balance existing in the ecosystem has
become dangerously unbalanced.
The constant felling of trees has
reduced the area of habitat of animals.
The killing of animals for a certain
item, for the “hunting attitude”, for
religious reasons, for museum
specimens, and for many more reasons
have also led to extinction of animals.
In the past 2 centuries, nearly 200 –
300 species of animals have become
extinct.
The balance between the various parts of an ecosystem are finely
balanced to an extent that one cannot exist without another.
If one species of an animal becomes extinct, it may lead to a chain of
extinction of other animals.
For example, consider a simple food web consisting of Eagle, Snake,
Grasshopper, Frog, and Owl. Let us imagine that these animals are unique
to a particular area and there are no other animals in that area.
Now, let us say that the
grasshoppers cease to
exist. Then, due to lack
of food, the frogs will
become extinct and the
reptiles will lose a part
of their food. Since the
frogs have become
extinct, there is no food
available for the snakes
and the owls leading to
their extinction. Since
the snakes have
disappeared, the eagles
will also become extinct.
Now let us say that the
snakes have become
extinct. Since there is
no food available for the
eagles, they will become
extinct. As there are no
predators to eat them,
the number of
grasshoppers and frogs
will increase. Since the
frogs consume the
grasshoppers and are
also increasing in
number, a time will come
when the grasshoppers
will become extinct.
This leads to the
extinction of the frogs
and ultimately the owls
as there is no food
available for them.
Now let us consider the
extinction of eagles.
Since there are no
predators hunting them,
the snakes will increase in
number. This leads to the
extinction of frogs and
grasshoppers as there
are more snakes feeding
on them than usual. Since
there is no food available
for the snakes and owls
they will become extinct.
Conservation can be done by :
Imposing hunting restrictions.
Making Security more tighter in Sanctuaries, National Parks, Bio-reserves,
etc..
Making rules more strict and ensure that they are properly implemented.
Banning hunting, selling and capturing of rare animals.
People making sure they do not buy anything made up of fur, leather, or any
other animal product.
Ensure proper inspection of goods to ensure that animal skins are not shipped
out of the country.
Fauna is an important part of our ecosystem and cannot be isolated from
the other parts of the ecosystem.
Humans should reduce reshaping of the environment and should ensure
that none of the animals should become extinct due to reasons which are
not caused by Nature.