NCERT Textbook: Forests- Our Lifeline | Science Class 7 PDF Download

 Page 1


SCIENCE 142
Forests: Our Lifeline
12
O
ne evening Boojho entered the
park with an elderly person. He
introduced him to his friends.
Prof Ahmad was a scientist working in
the university. The children started
playing while Prof Ahmad sat on a
bench in the corner. He was tired as he
had participated in the golden jubilee
celebrations of the town. After a while,
the children also came and sat around
him. They wanted to know about the
celebrations. Prof Ahmad told them that
after the cultural programme, the
senior people discussed the town’s
unemployment problem. A plan was
proposed to put up a factory by clearing
an area of the forest just outside the
town. This would give the increasing
population of the town a chance to get
jobs. The children were very surprised
when Prof Ahmad told them that many
people had objected to this idea.
“This is because the forests serve as
green lungs and water purifying systems
in nature”, Prof Ahmad explained. The
children were confused. Prof Ahmad
realised that the children had not visited
a forest. The children also wanted to
know more about the forest, so they
decided to visit it with Prof Ahmad.
12.1 VISIT TO A FOREST
One Sunday morning, the children
packed a few things like a knife, a hand
lens, a stick, a notebook and walked
together through a forest trail near a
village. On their way, they met Tibu, a
young boy of their age group, of nearby
village, who was taking cattle for grazing
along with his aunt. He was very agile,
running here and there to keep the herd
together. When he saw the children,
Tibu also started walking along with
them, while his aunt went on a different
path. As soon as they entered the forest
Tibu raised his hand and signalled them
to keep quiet because noise could
disturb the animals living in the forest.
Tibu then took them to a place at a
height to show them the broad view of
the forest. Children were surprised
because they could not see any land
(Fig. 12.1). The different treetops had
formed green cover over the land. However,
the cover was not uniformly green. The
Fig. 12.1  A view of a forest
Reprint 2024-25
Page 2


SCIENCE 142
Forests: Our Lifeline
12
O
ne evening Boojho entered the
park with an elderly person. He
introduced him to his friends.
Prof Ahmad was a scientist working in
the university. The children started
playing while Prof Ahmad sat on a
bench in the corner. He was tired as he
had participated in the golden jubilee
celebrations of the town. After a while,
the children also came and sat around
him. They wanted to know about the
celebrations. Prof Ahmad told them that
after the cultural programme, the
senior people discussed the town’s
unemployment problem. A plan was
proposed to put up a factory by clearing
an area of the forest just outside the
town. This would give the increasing
population of the town a chance to get
jobs. The children were very surprised
when Prof Ahmad told them that many
people had objected to this idea.
“This is because the forests serve as
green lungs and water purifying systems
in nature”, Prof Ahmad explained. The
children were confused. Prof Ahmad
realised that the children had not visited
a forest. The children also wanted to
know more about the forest, so they
decided to visit it with Prof Ahmad.
12.1 VISIT TO A FOREST
One Sunday morning, the children
packed a few things like a knife, a hand
lens, a stick, a notebook and walked
together through a forest trail near a
village. On their way, they met Tibu, a
young boy of their age group, of nearby
village, who was taking cattle for grazing
along with his aunt. He was very agile,
running here and there to keep the herd
together. When he saw the children,
Tibu also started walking along with
them, while his aunt went on a different
path. As soon as they entered the forest
Tibu raised his hand and signalled them
to keep quiet because noise could
disturb the animals living in the forest.
Tibu then took them to a place at a
height to show them the broad view of
the forest. Children were surprised
because they could not see any land
(Fig. 12.1). The different treetops had
formed green cover over the land. However,
the cover was not uniformly green. The
Fig. 12.1  A view of a forest
Reprint 2024-25
FORESTS: OUR LIFELINE 143
environment was peaceful and a cool
breeze was blowing. This made children
quite fresh and happy.
While coming down, they got excited
on hearing a sudden sound of birds and
some noise from the top branches of the
trees. Tibu told them to relax since it
was a normal phenomenon here.
Because of the children’s presence, some
monkeys had climbed higher up on the
trees where they disturbed the birds.
Animals often give this type of warning
call to alert other animals. Tibu also told
that many other animals like boar,
bison, jackals, porcupine, elephants live
in the deeper areas of the forest
(Fig. 12.2). Prof Ahmad cautioned
children that they should not go deep
into the forest.
Boojho and Paheli remembered that
they have studied about forests as
Fig. 12.2  Some forest animals
Fig. 12.3  Forest as habitat
an example of a habitat in Class VI
(Fig. 12.3). They could see now how the
forest provides a home for many animals
and plants.
Reprint 2024-25
Page 3


SCIENCE 142
Forests: Our Lifeline
12
O
ne evening Boojho entered the
park with an elderly person. He
introduced him to his friends.
Prof Ahmad was a scientist working in
the university. The children started
playing while Prof Ahmad sat on a
bench in the corner. He was tired as he
had participated in the golden jubilee
celebrations of the town. After a while,
the children also came and sat around
him. They wanted to know about the
celebrations. Prof Ahmad told them that
after the cultural programme, the
senior people discussed the town’s
unemployment problem. A plan was
proposed to put up a factory by clearing
an area of the forest just outside the
town. This would give the increasing
population of the town a chance to get
jobs. The children were very surprised
when Prof Ahmad told them that many
people had objected to this idea.
“This is because the forests serve as
green lungs and water purifying systems
in nature”, Prof Ahmad explained. The
children were confused. Prof Ahmad
realised that the children had not visited
a forest. The children also wanted to
know more about the forest, so they
decided to visit it with Prof Ahmad.
12.1 VISIT TO A FOREST
One Sunday morning, the children
packed a few things like a knife, a hand
lens, a stick, a notebook and walked
together through a forest trail near a
village. On their way, they met Tibu, a
young boy of their age group, of nearby
village, who was taking cattle for grazing
along with his aunt. He was very agile,
running here and there to keep the herd
together. When he saw the children,
Tibu also started walking along with
them, while his aunt went on a different
path. As soon as they entered the forest
Tibu raised his hand and signalled them
to keep quiet because noise could
disturb the animals living in the forest.
Tibu then took them to a place at a
height to show them the broad view of
the forest. Children were surprised
because they could not see any land
(Fig. 12.1). The different treetops had
formed green cover over the land. However,
the cover was not uniformly green. The
Fig. 12.1  A view of a forest
Reprint 2024-25
FORESTS: OUR LIFELINE 143
environment was peaceful and a cool
breeze was blowing. This made children
quite fresh and happy.
While coming down, they got excited
on hearing a sudden sound of birds and
some noise from the top branches of the
trees. Tibu told them to relax since it
was a normal phenomenon here.
Because of the children’s presence, some
monkeys had climbed higher up on the
trees where they disturbed the birds.
Animals often give this type of warning
call to alert other animals. Tibu also told
that many other animals like boar,
bison, jackals, porcupine, elephants live
in the deeper areas of the forest
(Fig. 12.2). Prof Ahmad cautioned
children that they should not go deep
into the forest.
Boojho and Paheli remembered that
they have studied about forests as
Fig. 12.2  Some forest animals
Fig. 12.3  Forest as habitat
an example of a habitat in Class VI
(Fig. 12.3). They could see now how the
forest provides a home for many animals
and plants.
Reprint 2024-25
SCIENCE 144
The land where the children were
walking was uneven and covered with
many trees. Tibu helped them to identify
sal, teak, semal, sheesham, neem,
palash, fig, khair, amla, bamboo,
kachnar (Fig. 12.4). Prof Ahmad pointed
out that there are several other trees,
shrubs, herbs and grasses in the forest.
The forest floor and the trees were also
covered with different types of creepers
and climbers. The sun was barely visible
through the leaves of the trees, making
it quite dark inside the forest.
Activity 12.1
Observe the various things in your home
and make a list of those which are made
from material which may have been
obtained from the forest.
You might have many wooden items
on your list like plywood, fuel wood,
boxes, paper, matchsticks, and
furniture. Do you know that gum, oils,
spices, fodder for animals and medicinal
plants are also some of the products
which we get from the forest (Fig. 12.5).
Fig. 12.4  Some forest plants
Semal
Sheesham
Neem
Bambooo
Reprint 2024-25
Page 4


SCIENCE 142
Forests: Our Lifeline
12
O
ne evening Boojho entered the
park with an elderly person. He
introduced him to his friends.
Prof Ahmad was a scientist working in
the university. The children started
playing while Prof Ahmad sat on a
bench in the corner. He was tired as he
had participated in the golden jubilee
celebrations of the town. After a while,
the children also came and sat around
him. They wanted to know about the
celebrations. Prof Ahmad told them that
after the cultural programme, the
senior people discussed the town’s
unemployment problem. A plan was
proposed to put up a factory by clearing
an area of the forest just outside the
town. This would give the increasing
population of the town a chance to get
jobs. The children were very surprised
when Prof Ahmad told them that many
people had objected to this idea.
“This is because the forests serve as
green lungs and water purifying systems
in nature”, Prof Ahmad explained. The
children were confused. Prof Ahmad
realised that the children had not visited
a forest. The children also wanted to
know more about the forest, so they
decided to visit it with Prof Ahmad.
12.1 VISIT TO A FOREST
One Sunday morning, the children
packed a few things like a knife, a hand
lens, a stick, a notebook and walked
together through a forest trail near a
village. On their way, they met Tibu, a
young boy of their age group, of nearby
village, who was taking cattle for grazing
along with his aunt. He was very agile,
running here and there to keep the herd
together. When he saw the children,
Tibu also started walking along with
them, while his aunt went on a different
path. As soon as they entered the forest
Tibu raised his hand and signalled them
to keep quiet because noise could
disturb the animals living in the forest.
Tibu then took them to a place at a
height to show them the broad view of
the forest. Children were surprised
because they could not see any land
(Fig. 12.1). The different treetops had
formed green cover over the land. However,
the cover was not uniformly green. The
Fig. 12.1  A view of a forest
Reprint 2024-25
FORESTS: OUR LIFELINE 143
environment was peaceful and a cool
breeze was blowing. This made children
quite fresh and happy.
While coming down, they got excited
on hearing a sudden sound of birds and
some noise from the top branches of the
trees. Tibu told them to relax since it
was a normal phenomenon here.
Because of the children’s presence, some
monkeys had climbed higher up on the
trees where they disturbed the birds.
Animals often give this type of warning
call to alert other animals. Tibu also told
that many other animals like boar,
bison, jackals, porcupine, elephants live
in the deeper areas of the forest
(Fig. 12.2). Prof Ahmad cautioned
children that they should not go deep
into the forest.
Boojho and Paheli remembered that
they have studied about forests as
Fig. 12.2  Some forest animals
Fig. 12.3  Forest as habitat
an example of a habitat in Class VI
(Fig. 12.3). They could see now how the
forest provides a home for many animals
and plants.
Reprint 2024-25
SCIENCE 144
The land where the children were
walking was uneven and covered with
many trees. Tibu helped them to identify
sal, teak, semal, sheesham, neem,
palash, fig, khair, amla, bamboo,
kachnar (Fig. 12.4). Prof Ahmad pointed
out that there are several other trees,
shrubs, herbs and grasses in the forest.
The forest floor and the trees were also
covered with different types of creepers
and climbers. The sun was barely visible
through the leaves of the trees, making
it quite dark inside the forest.
Activity 12.1
Observe the various things in your home
and make a list of those which are made
from material which may have been
obtained from the forest.
You might have many wooden items
on your list like plywood, fuel wood,
boxes, paper, matchsticks, and
furniture. Do you know that gum, oils,
spices, fodder for animals and medicinal
plants are also some of the products
which we get from the forest (Fig. 12.5).
Fig. 12.4  Some forest plants
Semal
Sheesham
Neem
Bambooo
Reprint 2024-25
FORESTS: OUR LIFELINE 145
Fig. 12.6  Some crown shapes
Based on the products that we get
from plants, try to fill Table 12.1. One
example of each plant is already given.
Fill the table by adding more examples.
Sheila wondered who would have
planted these trees. Prof Ahmad replied
that in nature trees produce enough
seeds. The forest floor provides
favourable conditions for them to
germinate and develop into seedlings
Prof Ahmad asked children to look
up and observe how the branches of the
tall trees look like a roof over the other
plants in the forest. He told them that
this is called a canopy (Fig. 12.7).
Activity 12.2
Visit a forest or a park in your
neighbourhood. Observe the trees and
try to identify them. You can take the
help of some elders or books on trees.
List the characteristics of the trees that
you observe, such as the height, shape
of leaves, crown, flowers, and fruits. Also
draw the crowns of some trees.
Prof Ahmad pointed out that trees
had crowns of different types and sizes.
These had created different horizontal
layers in the forest. These are known as
understoreys (Fig. 12.7). Giant and tall
trees constituted the top layer followed
by shrubs and tall grasses, and herbs
formed the lowest layer.
Table 12.1 Plants and their products
Gum Timber Medicinal Oil
Babool Sheesham Neem Sandalwood
Sealing wax
Gum
Catechu
Honey
Wooden
statue
Fig. 12.5  Forest products
and saplings. Some grow up into trees.
He added that branchy part of a tree
above the stem is known as the crown
of the tree (Fig. 12.6).
Reprint 2024-25
Page 5


SCIENCE 142
Forests: Our Lifeline
12
O
ne evening Boojho entered the
park with an elderly person. He
introduced him to his friends.
Prof Ahmad was a scientist working in
the university. The children started
playing while Prof Ahmad sat on a
bench in the corner. He was tired as he
had participated in the golden jubilee
celebrations of the town. After a while,
the children also came and sat around
him. They wanted to know about the
celebrations. Prof Ahmad told them that
after the cultural programme, the
senior people discussed the town’s
unemployment problem. A plan was
proposed to put up a factory by clearing
an area of the forest just outside the
town. This would give the increasing
population of the town a chance to get
jobs. The children were very surprised
when Prof Ahmad told them that many
people had objected to this idea.
“This is because the forests serve as
green lungs and water purifying systems
in nature”, Prof Ahmad explained. The
children were confused. Prof Ahmad
realised that the children had not visited
a forest. The children also wanted to
know more about the forest, so they
decided to visit it with Prof Ahmad.
12.1 VISIT TO A FOREST
One Sunday morning, the children
packed a few things like a knife, a hand
lens, a stick, a notebook and walked
together through a forest trail near a
village. On their way, they met Tibu, a
young boy of their age group, of nearby
village, who was taking cattle for grazing
along with his aunt. He was very agile,
running here and there to keep the herd
together. When he saw the children,
Tibu also started walking along with
them, while his aunt went on a different
path. As soon as they entered the forest
Tibu raised his hand and signalled them
to keep quiet because noise could
disturb the animals living in the forest.
Tibu then took them to a place at a
height to show them the broad view of
the forest. Children were surprised
because they could not see any land
(Fig. 12.1). The different treetops had
formed green cover over the land. However,
the cover was not uniformly green. The
Fig. 12.1  A view of a forest
Reprint 2024-25
FORESTS: OUR LIFELINE 143
environment was peaceful and a cool
breeze was blowing. This made children
quite fresh and happy.
While coming down, they got excited
on hearing a sudden sound of birds and
some noise from the top branches of the
trees. Tibu told them to relax since it
was a normal phenomenon here.
Because of the children’s presence, some
monkeys had climbed higher up on the
trees where they disturbed the birds.
Animals often give this type of warning
call to alert other animals. Tibu also told
that many other animals like boar,
bison, jackals, porcupine, elephants live
in the deeper areas of the forest
(Fig. 12.2). Prof Ahmad cautioned
children that they should not go deep
into the forest.
Boojho and Paheli remembered that
they have studied about forests as
Fig. 12.2  Some forest animals
Fig. 12.3  Forest as habitat
an example of a habitat in Class VI
(Fig. 12.3). They could see now how the
forest provides a home for many animals
and plants.
Reprint 2024-25
SCIENCE 144
The land where the children were
walking was uneven and covered with
many trees. Tibu helped them to identify
sal, teak, semal, sheesham, neem,
palash, fig, khair, amla, bamboo,
kachnar (Fig. 12.4). Prof Ahmad pointed
out that there are several other trees,
shrubs, herbs and grasses in the forest.
The forest floor and the trees were also
covered with different types of creepers
and climbers. The sun was barely visible
through the leaves of the trees, making
it quite dark inside the forest.
Activity 12.1
Observe the various things in your home
and make a list of those which are made
from material which may have been
obtained from the forest.
You might have many wooden items
on your list like plywood, fuel wood,
boxes, paper, matchsticks, and
furniture. Do you know that gum, oils,
spices, fodder for animals and medicinal
plants are also some of the products
which we get from the forest (Fig. 12.5).
Fig. 12.4  Some forest plants
Semal
Sheesham
Neem
Bambooo
Reprint 2024-25
FORESTS: OUR LIFELINE 145
Fig. 12.6  Some crown shapes
Based on the products that we get
from plants, try to fill Table 12.1. One
example of each plant is already given.
Fill the table by adding more examples.
Sheila wondered who would have
planted these trees. Prof Ahmad replied
that in nature trees produce enough
seeds. The forest floor provides
favourable conditions for them to
germinate and develop into seedlings
Prof Ahmad asked children to look
up and observe how the branches of the
tall trees look like a roof over the other
plants in the forest. He told them that
this is called a canopy (Fig. 12.7).
Activity 12.2
Visit a forest or a park in your
neighbourhood. Observe the trees and
try to identify them. You can take the
help of some elders or books on trees.
List the characteristics of the trees that
you observe, such as the height, shape
of leaves, crown, flowers, and fruits. Also
draw the crowns of some trees.
Prof Ahmad pointed out that trees
had crowns of different types and sizes.
These had created different horizontal
layers in the forest. These are known as
understoreys (Fig. 12.7). Giant and tall
trees constituted the top layer followed
by shrubs and tall grasses, and herbs
formed the lowest layer.
Table 12.1 Plants and their products
Gum Timber Medicinal Oil
Babool Sheesham Neem Sandalwood
Sealing wax
Gum
Catechu
Honey
Wooden
statue
Fig. 12.5  Forest products
and saplings. Some grow up into trees.
He added that branchy part of a tree
above the stem is known as the crown
of the tree (Fig. 12.6).
Reprint 2024-25
SCIENCE 146
They had a close look at the bushes.
While doing that their hair and clothes
had seeds and thorns clinging to them.
They came across numerous insects,
spiders, squirrels, ants and various
other small animals on the bark of the
trees, plant leaves and on decaying
leaves on the forest floor (Fig. 12.8). They
started making sketches of these
creatures. The forest floor seemed dark
coloured and was covered with a layer
of dead and decaying leaves, fruits,
seeds, twigs and small herbs. The
decaying matter was moist and warm.
Children picked up various seeds and
leaves for their collection. Walking over
the dead leaf layer on the forest floor
was like walking over a spongy carpet!
Is the decaying matter always warm?
Prof Ahmad suggested that the children
could perform an activity to get an
answer to this question.
Fig. 12.7  Canopy and under storeys in a forest
“Would we see similar kind of trees
in every forest?”—asked Boojho.
Prof Ahmad said, “No, due to different
climatic conditions there are variations
in the types of trees and other plants.
The types of animals also differ from
forest to forest.”
A few children were busy watching
beautiful butterflies fluttering here and
there on the flowers of shrubs and herbs.
Understorey
Fig. 12.8  Forest floor
Canopy
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