AP BIOLOGY

Detailed explanation-1: -Desertification is the degradation process by which a fertile land changes itself into a desert by losing its flora and fauna, this can be caused by drought, deforestation, climate change, human activities or improper agriculture.

Detailed explanation-2: -’Climatic variations’ and ‘Human activities’ can be regarded as the two main causes of desertification. removal of the natural vegetation coverby taking too much fuel wood, agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity.

Detailed explanation-3: -Overfarming or drought can change the soil so that rain no longer penetrates, and the plants lose the water they need to grow. If the changing force is lifted-drought ends or cattle are removed, for example-but the land cannot recover, it is desertified.

Detailed explanation-4: -It occurs when trees and bushes are stripped away for fuelwood and timber, or to clear land for cultivation. Wind and water erosion aggravate the damage, carrying away topsoil and leaving behind a highly infertile mix of dust and sand. It is the combination of these factors that transforms degraded land into desert.

Detailed explanation-5: -Deforestation causes soil erosion that in turn, cause the removal of top soil. This cause exposure of the lower layers, and removal of humus which leads to loss of fertile soil. Loss of fertile soil does not support plant growth which leads to desertification.