NCERT 7th Class (CBSE) Science: Forests: Our Lifeline

Question: Why forest floor seemed to be dark coloured?

Answer: The forest floor seemed dark coloured as it is covered with a layer of dead and decaying matters like leaves, fruits, seeds, twigs and small herbs.

Question: Define the following: Crown, Understoreys

Answer: Crown: The branchy part of tree above the stem is called crown.

Understoreys: Trees have crowns of different type and sizes, these creates different horizontal layers in the forest, these are known as understoreys.

Question: What do you mean by canopy?

Answer: Tall trees look like a roof over the other plants in the forest, this is called canopy.

Question: What is the interrelationship between plants, soil and decomposers?

Answer: Decomposers break down fallen leaves, branches, etc. into materials that plants can use. This also amends the soil so that it holds more water for longer periods of time. Soil is a living entity, made up of the dirt (inorganic sand, clay, etc.), nutrients, and microbes. The decomposers live in the soil, which is enriched by the dead forest material.

Question: What happens if an animal dies in the forest?

Answer: The dead animals become food for vultures, crows, jackal and insects and in this way nutrients are cycled, thus we say nothing goes waste in forest.

Question: Differentiate between humus and decomposers.

Answer: A dark-brown or black organic substance made up of decayed plant or animal matter. Humus provides nutrients for plants and increases the ability of soil to retain water. But decomposers are the microorganisms that convert the dead plants and animals to humus.

Question: If there were fewer trees, how will the water cycle be affected?

Answer: Forests help in bringing good rainfall in neighbouring areas. Forest also act as natural absorber of rain water and allows it to seep, it help in maintaining the water table throughout the year.

Question: Why even after a heavy rainfall, the ground in the forest remains dry?

Answer: The upper layer of the forest canopy intercepts the flow of rain drops and most of the water comes down through the branches and the stems of the tree, from the leaves rain water drips slowly over branches of the shrubs and herbs, thus the ground does not wet at all.

Question: What are the benefits of residing in nearby forest area?

Answer: Following are the benefits of residing in nearby forest area:

1. Pleasant weather
2. Less noise pollution
3. Good rainfall