La destruction du couvert forestier consécutive à l'exploitation forestière de bois d'ouvre en forêt dense tropicale humide africaine ou américaine

Abstract

Articles in the media that point to logging as the main driver of tropical forest loss have become commonplace. However, this is a misconception that can be attributed to inadequate knowledge of actual forest con- ditions on the one hand, and to the confla- tion of logging and agricultural clearance on the other hand. This article, written by a practitioner with a thorough knowledge of the tropical forest context, sets out to assess the impacts of logging on dense tropical rainforests in Africa and South America. In the interests of accuracy, the article distinguishes between the different phases of a logging operation: establish- ment of the base camp, building of logging roads to ship out the timber and actual felling. Different scenarios are described according to the richness of forest environ- ments, where harvested volumes vary from 3 to 15 m3/ha. These estimations confirm that the destruction of forest cover is so low that, except in radical situations, logging is not a threat to the sustainability of tropical forests. Opening up road networks and log- ging roads affects 4.5% to 5.5% of forest cover. Clear-felled areas never exceed 4% of the forest cover and the figure drops to less than 2% in highly or moderately species-rich forests. Logging is therefore directly responsible for only 5.5% to 8.5% of forest destruction. Although the figure can rise to 12% to 16% in rich forest envi- ronments, it does not take into account the natural dynamics of biomass reconstitution between logging sequences. In Southeast Asia where logging is more intensive due to very high commercial potential, forest cover reconstitutes within 20 years. While the economic value of dense tropical rain- forests declines with logging, their ecologi- cal and biological value remains virtually intact.