Probably more than 10 million hectares are degraded each year by the action of loggers, firewood collectors, and livestock herders. Although the land remains under forest use, its composition and biological functions are compromised by human intervention. The chief cause of forest degradation is exploitative logging, with its selective removal of tree species, felling damage to the residual forest, soil damage from road construction and log skidding, and the displacement of bird and mammal species. Logging roads provide new access for farmers and ranchers who come to clear and burn the logged-over forests once the skidders and chainsaws have left. Forest degradation also occurs as a consequence of intensive fuelwood collection and overgrazing by livestock and wildlife.
More research is required on the scale and impact of degradation on all types of forests. . . .