The animals in forests are of various types. These could be herbivores, carnivores, microorganisms, etc. These play an important role in maintaining the food chains.
(i) Microorganisms convert the dead plants and animals into humus. This humus helps in returning the nutrients back to the soil. These are absorbed by plants.
(ii) The animals also help in dispersing the seeds of certain plants.
(iii) The decaying animal dung provides nutrients.
All these activities of animals dwelling in the forest help it to grow and regenerate.

The four factors which are responsible for the destruction of forests are
(i) Construction of roads.
(ii) Construction of buildings.
(iii) Industrial development.
(iv) Increasing demand of wood.

Autotrophs: Such living organisms which are capable of manufacturing their own food by the process of photosynthesis by using CO₂ water and light. e.g., green plants.
Heterotrophs: Such organisms which are not capable of manufacturing their own food and depend for their food on other organisms are known as heterotrophs.
Saprotrophs: Such heterotrophs which obtain their nutrition from dead decaying organic material are called saprotrophs.

(i) Growing plants and trees in the open area in the school.
(ii) Arrangement for water harvesting.
(iii) Reporting any kind of water leakage in the school.

Since, all food chains are interlinked disturbance in one food chain will affect the other food chain in a forest.

(i) If forests disappear, the quantity of carbon dioxide in air will rise, leading to the increase in earth's temperature.
(ii) In the absence of trees and plants, the animals will lack food and shelter.
(iii) In the absence of trees, the soil will not hold water, this will cause floods.
(iv) Deforestation is a menace to our life and environment.

(a) Deforestation: The cutting down of trees for commercial purposes is called Deforestation.
(b) Deforestation affects wild animals and human beings
(1) In absence of plants, the animals will not get food and shelter.
(2) In absence of plants, carbon dioxide in air will increase resulting in increase in Earth's temperature.
(3) In absence of plants, soil will not hold water, which will cause floods.
(4) Deforestation will endanger our life and environment.

The papers are made from wood pulp. We derive wood by cutting down trees. If we recycling existing quantity of paper in the market and will not let it decompose, we can stop cutting of forest trees for new raw materials required for paper making.It takes years to grow a tree and cutting a tree takes only few minutes. So, we should give a serious thought before cutting a single tree even and should encourage recycling of papers every where In our country and in the world.

We must protect our forest because:
(i) Forests provide us with oxygen.
(ii) They protect soil and provide habitat to a large number of animals.
(iii) Forest help in bringing good rainfall in neighbouring areas.
(iv) They are sources of medicines, timber and many other useful products.