how does deforestation affects the rainfall pattern of the area
Answers
Climate change: Trees are 50% carbon. When forests are cleared for agriculture or urban development, they are often just being burned down. This biomass burning directly releases CO2 into the atmosphere. Decomposing of wood or forest-floor biomass by microorganisms also releases CO2, although at a much slower pace than burning. Even when forest is turned into timber for construction, the wood will eventually be decomposed by microorganism and CO2 is released. A 2007 assessment by the Intergovernmental Panel on Climate Change (IPCC) estimated that 17% of annual CO2 emission comes from deforestation.
Soil: When an area is deforested for agriculture, farmers typically burn the trees and vegetation to create a layer of ash to enrich the soil. But the nutrient reservoir is lost and the soil often become unable to support farming in just a few years. Flooding and erosion rates also become higher after deforestation.
Social impacts: Tropical forests are home to millions of indigenous people who make their livings through subsistence agriculture, hunting, and gather. Deforestation in indigenous territories rob these people of their livelihood and often triggers violent conflicts.
Precipitation: Forest is an important part of the earth’s water cycle. Rain water that falls on forests is recycled by the trees back into the atmosphere through evapotranspiration. Also, the rough surface of the forest canopy stimulates convection and local rainfall. Deforestation would alter the rainfall pattern.
Biodiversity: Although tropical forests cover only about 7% of the earth’s land surface, they probably harbor about half of all plant and animal species. With deforestation, many species will become vulnerable or even extinct. Cascading changes in the types of plants and animals can rapidly reduce biodiversity in the forest that remains.
Urban heat island effect: Urban forests improve the human habitats in many ways; they filter air, water, sunlight, provide shelter to animals and recreational area for people, and moderate the urban heat island effect. Clearing urban forests would eliminate these benefits.
How exactly does deforestation impact rainfall?
trees absorb moisture, usually from the soil and/or standing water that their roots penetrate. this water is carried from the root structure all the way to the highest extremities of the tree. In the chemical process of photosynthesis that the tree uses to convert sunlight into stored energy water and carbon dioxide are chemically combined using captured solar energy to build glucose sugar molecules. Trees attach these molecules together in starch, to store energy, as well as in cellulose and lignin to build cell walls and new structures. In the process water soluble nutrients are absorbed by the roots along with the water and transported to the trees extremities. Because the surface area of the leaf or needle structures where this photosynthesis process takes place are so large it is inevitable that a lot of the water absorbed by the roots evaporates into the air around the tree and becomes water vapor. Water vapor rises to form clouds and eventually precipitates back out as rain or snow completing the cycle. When a large area of forest is removed and replaced with annual crops or pasture lands the new plants growing there are small compared to a tree so they have a much smaller surface area and transpire far less water from the root structure into the air as water vapor. Less water vapor means less cloud formation down wind and less rainfall.