Class Notes NCERT Solutions for CBSE Students
Question: Explain the reasons behind deforestation.
Answer: Population explosion: Large areas of forests have been cleaned for agriculture, factories, road and rail tracks, industries, mining and quarrying have seriously affected the forest. Expanding agriculture is one of the most important causes of deforestation. As demands on agricultural products rise more and more land is brought under cultivation for which forests are cleared, grass-lands ploughed, uneven grounds leveled, marshes drained and even land under water is reclaimed. Forest fires also destroy trees, seeds and the animal life. A part from these Grazing and gnawing mammals trample the young plants, and damage their trunks and roots. Deforestation can endanger our life and environment.
Question: Explain why forest is called “the dynamic living entity”?
Answer: The wide variety of animals helps the forest to regenerate and grow. In forest, plants produce food. All animals, whether herbivores or carnivores, depend ultimately on plants for food. Organisms which feed on plants often get eaten by other organisms, and so on. For example, grass is eaten by insects, which in turn, is taken by the frog. The frog is consumed by snakes. This is said to form a food chain:
Grass→ insects→ frog→ snake→ eagle
Decomposers play an important role in the forest. They feed upon the dead plant and animal tissues and convert them into a dark coloured substance called humus. For example Fungi grow on decaying fruits and vegetables and convert them into humus. By harbouring greater variety of plants, the forest provides good opportunities for food and habitat for the herbivores. Larger number of herbivores means increased availability of food for a variety of carnivores, the wide variety of animals helps the forest to regenerate and grow. Thus forest is the dynamic living entity that is the full of life and vitality.
