Notes of chapter: Forests: Our Lifeline are presented below. Indepth notes along with worksheets and NCERT Solutions for Class 7.
Forest is a large area covered with trees, gives shelter to many animals, birds and many other living organisms. A fresh and cool breeze blows in forests.
(2) Animals make different sounds to show their feelings. Sometimes they make voice to alert other animals from danger. Animals like boar, bison, jackals, elephants, rhinoceros etc live in deeper area of forest.
(5) Activity 1
Forest Products used at home-
(6) Trees grow themselves in forests. They produce enough seeds for new plants. The forest floor provides favourable conditions for seed to germinate and develop into seedlings and saplings.
(7) Crown of the tree-
The branchy part of tree which is above the stem is called crown of the tree.
The roof like layer formed by crowns of tall trees in forests is known as canopy.
(9) Activity 2
Trees in my neighbourhood
|S.N.||Name of the tree||Height of the tree||Crown of the tree||Leaf of the tree||Fruit of the tree||Flower of the tree|
|1.||Neem||50 – 65 ft||round||Thin and long||Small,green in colour||White|
|2.||Banyan||100ft||round||broad||Small, red in colour||Red|
|3.||Mango||35 – 40 ft||round||Thin and long||yellow||White|
|4.||Banana||10 – 16ft||fountain||Very long||yellow||Light pink|
|5.||Papaya||16 – 33 tf||fountain||broad||yellow||white|
(10)Understoreys of the tree-
Understoreys are the layer of crowns of different trees lying between canopy and ground vegetation (grass).
(11) There are variations in the types of tree, animals, birds, insects etc. in different forests due to different climatic conditions.
(12) Forest floor-
The forest floor is always covered with dead and decaying leaves, fruits, seeds, twigs and small herbs.
(13) Every part of the forest is dependent on the other parts. If we remove one component (eg:- tree)all other components would be affected.
Humus is a dark coloured substance which is prepared from dead plant by several organisms and micro- organisms. The presence of humus ensures that the nutrients of the dead plants and animals are released into the soil.
The microorganisms convert the dead plants and animals to humus are known as decomposers.
(16) The forests are called “lungs” because trees provide oxygen for animals’ respiration through photosynthesis. They also maintain the balance of oxygen and carbon dioxide in the atmosphere.
(17) Trees take in water from their roots and release water vapour into the air through evaporation.
(18) Many tribes live in forests. They depend on forests for shelter, food, water and medicines.
(19) The tall grass and dense bushes of the forests protect herbivores from carnivores.
(20) The animals also disperse the seeds of certain plants through their dung and help the forest to grow and regenerate. The animal’s dung also provides nutrients to the seedlings to grow.
(21) Rainwater does not stagnate in the forests because the flow of raindrops intercepted by canopy and most of the water coming down through branches and the stems of the tree.
(22) The forests also act as absorber of rain water and allow it to seep. It helps to maintain the water table through out the year.
(23) In the absence of trees, rain will hit the ground directly. It may cause the flood.
(24) Roots of the tree bind the soil together, but in their absence the soil can washed away during heavy rain.
(25) The weather of nearby area of the forests always remains cool and pleasant. Even noise pollution can not disturb the people of nearby areas because noise of vehicles absorbs by the forests.
(26) Reasons of not regenerating the forests-
(i) Construction of road
(ii) Construction of buildings
(iii) Industrial development
(iv) Increasing demand for wood
(v) Over grazing of animals
(vi) Indiscriminate felling of trees