Forests : Our Lifeline — Science STD 7 — Question

Structure of a Forest
A well-developed forest has different types of trees, climbers, creepers, herbs and shrubs. These make different layers in the forest, which are described below.
1. Canopy
The uppermost branches and leaves of tall trees which act like a roof over the other plants in the forest is called canopy. It is the highest layer of vegetation in the forest. The branchy part of a tree above the stem is known as the crown of the tree.


2. Understorey 
The different horizontal layers formed due to the different types of crowns in the forest are called understoreys. The constituents of understorey can be described as follows
(i) Top Layer It constitutes the giant and tall trees followed by shrubs and tall grasses.
(ii) Shrub Layer It has many shrubs and bushes of approximately 1-2 metres of height from the forest floor. It makes dense layer at some places of forest where enough sunlight is not present.
(iii) Herb Layer It occurs just below the shrub layer of plants. It is the lowest layer of vegetation in the forest having leafy plants. Most of the plants in herb layer have short lifespan. 
3. Forest Floor 
It is covered with different types of creepers. It has many kinds of insects, worms, toad stool, etc. Most of the forest floor is covered with dead and decaying leaves, fruits, seeds, twigs and small herbs.
Walking over the dead leaf layer on the forest floor feels like walking over a spongy carpet. It is generally dark as not much sunlight reaches here. Forest floor is warm and humid.
Thus, providing favourable conditions for seeds to germinate and develop into seedlings and saplings.