Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev

Science Class 7

Created by: Praveen Kumar

Class 7 : Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev

The document Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev is a part of the Class 7 Course Science Class 7.
All you need of Class 7 at this link: Class 7

Forests: Lifeline

Introduction to Forest

These forests have given Kerala its healing touch in the form of Ayurvedic medicines
Kerala, which is one of the India's southern states, is also known as "God's own country". It is rich in natural vegetation. The forests are spread over a large area, and consist of tropical wet evergreen, partly evergreen, deciduous and dry forests. Some plants found in these forests are known for their medicinal value. These forests have given Kerala its healing touch in the form of Ayurvedic medicines for the treatment of various ailments.

Endemic species

When an animal or a plant is found in a specific area, it is known as an endemic species.

Wayanad Wildlife Forest

It's a large collection of flora and fauna. Many endemic species of animals, such as pale-faced monkeys called bonnet macaques, striped-neck mongoose, small Indian civet, striped hyena, jackal, Indian fox, wild bear, giant squirrel, bison, chital and others, are found here. Kerala's forests have huge Neem trees that can grow up to a height of 50 to 65 feet. The Neem tree has high medicinal value and is said to treat around 40 diseases. The wood of the Neem tree is used to make a musical instrument, called the dhol.
Trees such as the bamboo, which can grow at the rate of 45 inches in a day, the fig tree, the amla tree or the Indian gooseberry, the Sal tree or the sandal wood tree, the teak tree and many more are all found in these forests. The crown, i.e. the branchy part of a tree above the stem, is not of the same type and size for all the trees. So they appear like different layers in the forest and are known as under storey. Apart from all these trees, the forest is covered with shrubs, herbs, tall grasses, creepers and climbers. The branches of the tall trees are just like a roof over the other plants, and are called the canopy. The soil of the forest is moist and warm because it is covered with leaves and fruits. The floor of the forest is a soft spongy carpet laid with dry leaves. Dead and decaying leaves, fruits and herbs produce a black substance called humus, which is good for the growth of the plants. Saprophytic organisms and micro-organisms convert the dead waste into humus. Plants are called producers because they prepare their own food. These producers are eaten by animals that are the primary consumers, which are, in turn, eaten by other animals that are the secondary consumers. Finally, the secondary consumers are eaten by the tertiary consumers.
Thus, forests play a very important role in the food chain. When forests are affected, they affect living beings such as animals and plants.

Importance of Forest

Forests play a vital role in the preservation of the water cycle.

Forests play a vital role in the preservation of the water cycle. Plants absorb water from the ground through their roots. Excess water from the plants is released into the atmosphere in the form of water vapour. This process is termed as transpiration. Plants release a huge amount of

water into the atmosphere through transpiration. A single apple tree looses as much as 30 litres of water in a day. The water vapour rises in the atmosphere and condenses to form clouds. The clouds move to the land due to sea breeze and bring rain. This is called precipitation. Excess water seeps into the ground and reaches the ground water table. By the process of transpiration and photosynthesis, forests maintain the temperature. During photosynthesis, plants take in to prepare food, and release and water vapour into the atmosphere. The more the number of trees, the more the oxygen; and the less the number of trees, the more the carbon dioxide in the atmosphere. A decrease in the number of trees results in global warming. Trees are the main source of oxygen.

Advantages of forests

Forests provide shelter for the animals and act as a protective camouflage. Forests provide shelter and food to the tribes living in the jungle.
Forest trees such as the bamboo are used in making furniture, baskets, ladders, etc. The teak tree is used to make furniture. The Neem tree is used for medicinal purposes. Forests also provide wood to make paper and other products such as gum, wax, rubber, and honey. There are major benefits from forests and so they should be protected.

Deforestation

Due to the rise in the population, trees are being cut down to obtain land for agriculture, industry and housing. This is known as deforestation. Due to this, many species become homeless. Forests are also lost due to forest fires and floods. If trees are cut down, then the carbon dioxide level increases. This leads to an increase in the temperature of the earth's surface, resulting in global warming. If forests disappear, then the soil becomes very loose, resulting in soil erosion. The fertility of the soil is maintained when the roots hold the trees and prevent soil erosion by wind and water.

Complete Syllabus of Class 7

Dynamic Test

Content Category

Related Searches

video lectures

,

Exam

,

mock tests for examination

,

Extra Questions

,

practice quizzes

,

MCQs

,

pdf

,

Important questions

,

Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev

,

ppt

,

Objective type Questions

,

Previous Year Questions with Solutions

,

Summary

,

Free

,

Viva Questions

,

Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev

,

Semester Notes

,

Chapter Notes - Forests: Our Lifeline Class 7 Notes | EduRev

,

shortcuts and tricks

,

past year papers

,

Sample Paper

,

study material

;