Deforestation


Deforestation is the removal of trees, often as a result of human
activities. Deforestation has been practiced by humans for thousands of
years chiefly as a result of clearing land for commercial and industrial
development, intensive collection of firewood, clearing of land for growing
crops and to deveop passture for grazing animals. The rate of clearance
increased during the second half of the ninenteenth century due to
agricultural expansion in Europe and there has been massive increases since
then. Currently major worries concern the loss of tropical rainforest, one
fifth of which was destroyed between 1960 and 1990. 12 million hectares of
tropical forest are lost each year, a land approximately the size of England.

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 transpiration. 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.

Forests are rich in biological diversity. Deforestation causes the
destruction of the habitats that support biological diversity.

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.