Explain deforestation.

(N/A) Deforestation is the conversion of forested land areas to non-forested ones.
According to an estimate,almost $40\%$ of forests have been lost in the tropics compared to only $1\%$ in the temperate region.
The present scenario of deforestation is particularly grim in India.
At the beginning of the twentieth century,forests covered about $30\%$ of the land of India.
By the end of the century,it shrunk to $19.4\%$.
The National Forest Policy $(1988)$ of India has recommended $33\%$ forest cover for the plains and $67\%$ for the hills.
The main reason is the conversion of forest to agricultural land to feed the increased human population.
Human activities like slash-and-burn agriculture,also called $Jhum$ cultivation,involve farmers cutting down trees and burning the plant remains.
The ash is used as a fertilizer,and the land is then used for farming or cattle grazing. Other causes include the use of fertilizers and the cutting of trees for industries and residential use.
The main consequences of deforestation include: $(a)$ Enhanced carbon dioxide concentration,$(b)$ Loss of biodiversity,$(c)$ Disturbed hydrologic cycles,$(d)$ Soil erosion,and $(e)$ Desertification.