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Deforestation has been practiced by humans for thousands of years chiefly as a result of clearing land for commercial and industrial development, cutting wood for house building and furniture-making, making paper, intensive collection of firewood, road construction, clearing of land for growing crops and to develop pasture for grazing animals.
The rate of clearance increased during the second half of the 19th century due to agricultural expansion in Europe. There have been massive increases since then. Currently major worries concern the loss of tropical rainforest, one fifth of which was destroyed between 1960 and 1990. Estimates of deforestation of tropical forest for the 1990s range from ca. 55,630 kmē to ca. 120,000 kmē each year.
Deforestation is often cited as one of the major causes of the enhanced greenhouse effect. Trees remove carbon (in the form of carbon dioxide) from the atmosphere during the process of photosynthesis. Both the rotting and burning of wood releases this stored carbon carbon dioxide back in to the atmosphere.
Pressure has been exerted on forests by the worldwide demand for wood and by local people who clear forests in their quests to establish an agrarian land base. Clearing of forests for the development of pasture for cattle has also resulted in deforestation as has the encroachment upon forests due to increasing human populations.
Deforestation promotes erosion of soil. Under normal circumstances trees and bushes and the forest floor act as a 'sponge' for rainfall, slowing its' overland and underground flow and releasing it back into the atmosphere through transpirationTranspiration is a continuous process caused by the evaporation of water from leaves of plants and its corresponding uptake from roots in the soil. Transpiration cools plants down and enables mass flow of minerals to where it is needed in the plant. Mass. Without the buffering effect of forest cover, rain impacting bare soil runs off, often causing flooding. In this environment, nutrients in the soil are leached off and the microorganisms which can replenish these nutrients are disturbed.
Some forests are rich in biological diversity. Deforestation can cause the destruction of the habitats that support biological diversity.
While the earliest example of deforestation is unclear (there is some controversy over the origin of the Sahara Desert for example), see history of Easter IslandEaster Island ( Polynesian: Rapa Nui ("Great Rapa"), Spanish: Isla de Pascua is an island in the south Pacific Ocean belonging to Chile. Administratively it is a province of the Chilean region of Valparaiso, although it is located 3,515 km (2,185 miles) w for clear evidence of the ecological impact of human activity.
One answer to the problem of deforestation is to build houses out of non-wood materials, such as brick, stone, concreteIn general, a concept is considered concrete if it is not abstract: it must be both particular and an individual, and hence occupy both space and time. To say that a physical object is concrete is to say, approximately, that it is a particular individual, and fiberglassThere is a disputed proposal to merge this article with glass-reinforced plastic. See the for discussion. Fiberglass or fibreglass is material made from extremely fine fibers of glass. It is widely used in the manufacture of insulation and textiles. It is. These materials have the additional benefits of being fireproof, waterproof, and pest-proof. Paper can be made of hempHemp is Cannabis grown for fibre, food, fuel, or other non-drug uses. Historically, the textile uses have been most important. Cannabis grown as hemp is the same species as that grown for marijuana, although millenia of selective breeding has resulted in fiber instead of wood. Recycled paper reduces the number of trees cut down. E-mails and web pages reduce the amount of wood paper used too. Some lumber companies are planting trees to repalce the trees taken. Hay, dry weeds, trash, garbage, husks, and stalks can be burned for energy instead of wood, although it still causes air pollution. Non-polluting energy generation includes solar cells, windmills, and geothermal energy. New methods are being developed to farm more food crops on less farm land, such as high- yield hybrid crops, greenhouses, autonomous building gardens, and hydroponics. The reduced farm land means less land is cleared for growing crops. In cyclical agriculture, cattle are grazed on farm land that is resting and rejuvenating. Cyclical agriculture prevents the soil from being overfarmed and stripped of its nutrients. Grass is allowed to grow on the resting farm land. The cows eat the grass and leave behind their dung - free fertilizer. This also reduces deforestation by using farmland to graze instead of using forest land.
Some societies are making efforts to stop or slow deforestation. In China, where large scale destruction of forests has occurred, each citizen must plant at least 11 trees every year. In western countries, increasing consumer demand for wood products that have been produced and harvested in a sustainable manner are causing forest landowners and forest industries to become increasingly accountable for their forest management and timber harvesting practices.
The Arbor Day Foundation 's Rain Forest Rescue program is a charity that helps to prevent deforestation. The charity uses donated money to buy up and preserve Rain Forest land before the lumber companies can buy it. The Arbor Day Foundation then protects the land from deforestation. This also preserves the way of life of the primitive tribes living on the forest land.