Deforestation of tropical forests ‘occurs in waves’
By Mark Kinver Science and environment reporter, BBC News
3 August 2010 Last updated at 05:17 ET An international team of researchers has developed a model that suggests degradation of tropical forests occurs in a series of “waves”. High-value trees were felled in the first “wave”, followed by a wave that removed mid-value timber before the remaining wood was felled for charcoal. The team hopes the model will help manage forests as vital carbon sinks and limit the loss of biodiversity. The findings appear in the Proceedings of the National Academy of Sciences. The researchers said an economic theory was used to provide a general model to predict patterns of tree loss. “This translates to a prediction that waves of forest degradation will emanate from major demand centres and expand into nearby forested areas, targeting resources in sequence, starting with those of highest value,” they wrote in their PNAS paper. “Such a sequence of demand, linked to resource utilisation, has been demonstrated for unmanaged fisheries … but has not been shown for the exploitation of differently valued tropical forest products.” The team used data collected in the area surrounding Tanzania’s largest city, Dar es Salaam, to see how far the degradation “waves” had travelled between 1991 and 2005. …
