Question

Explain how deforestation leads to reduced rainfall.

Answer 1

Hint: Deforestation is the cutting of trees in large numbers. We know that the roots of trees help to bind the soil together thus preventing soil erosion. These roots take up water and nutrients from the soil. These assist in the process of photosynthesis for the preparation of plant food. We also know that the excess water leaves the plants in the form of water vapor or even as water droplets by the process of transpiration or guttation respectively. Trees also play a major role in maintaining carbon dioxide levels in the atmosphere.

Complete answer:
Trees play a pivotal role in the cyclic flow of moisture from the soil to the atmosphere and back to the soil. Roots of trees travel far and wide in search of water. This water is absorbed by the roots and utilized by the plant for the process of photosynthesis. Due to the capillary action of the transpirational pull, the roots continue to absorb water from the soil. Thus, trees continue to add moisture to the atmosphere. Deforestation leads to decreased humidity in the atmosphere. Also, carbon dioxide is utilized by the plant in the process of carbon fixation. Reduced carbon dioxide levels in the atmosphere mean there would be no global warming. Lower temperatures would facilitate better precipitation thus increased rainfall in the area. During rainfall, the water droplets that get evaporated from the leaves also contribute to the increased moisture content of the atmosphere. The wind may move these moisture-laden clouds elsewhere causing rainfall in distant places. Thus we can say that deforestation not only brings scanty rainfall to the affected area but to other neighboring places as well.

Note: Deforestation not only causes reduced rainfall but it may also lead to floods causing mass destruction of agricultural as well as economically important crops. This is because the water holding capacity of the soil is reduced. Trees hold the soil particles together. In absence of trees, the soil gets loosened, the water does not seep down but is carried away leading to floods.