There are many causes of deforestation. The WWF reports that half of the trees illegally removed from forests are used as fuel.
Some other common reasons are:
To make more land available for housing and urbanization
To harvest timber to create commercial items such as paper, furniture and homes
To create ingredients that are highly prized consumer items, such as the oil from palm trees
To create room for cattle ranching
Common methods of deforestation are burning trees and clear cutting. These tactics leave the land completely barren and are controversial practices.
Clear cutting is when large swaths of land are cut down all at once. A forestry expert quoted by the Natural Resources Defense Council describes clear cutting as "an ecological trauma that has no precedent in nature except for a major volcanic eruption."
Burning can be done quickly, in vast swaths of land, or more slowly with the slash-and-burn technique. Slash and burn agriculture entails cutting down a patch of trees, burning them and growing crops on the land. The ash from the burned trees provides some nourishment for the plants and the land is weed-free from the burning. When the soil becomes less nourishing and weeds begin to reappear over years of use, the farmers move on to a new patch of land and begin the process again