Claims that tropical forests are declining cannot be backed up by hard evidence, according to new research from the University of Leeds.
This major challenge to conventional thinking is the surprising finding of a study published today in the Proceedings of the US National Academy of Sciences by Dr Alan Grainger, Senior Lecturer in Geography and one of the world's leading experts on tropical deforestation.
"Every few years we get a new estimate of the annual rate of tropical deforestation, said Dr Grainger. They always seem to show that these marvellous forests have only a short time left. Unfortunately, everybody assumes that deforestation is happening and fails to look at the bigger picture what is happening to forest area as a whole.
In the first attempt for many years to chart the long-term trend in tropical forest area, he spent more than three years going through all available United Nations data with a fine toothcomb and found some serious problems.
The errors and inconsistencies I have discovered in the area data raise too many questions to provide convincing support for the accepted picture of tropical forest decline over the last 40 years, he said. Scientists all over the world who have used these data to make predictions of species extinctions and the role of forests in global climate change will find it helpful to revisit their findings in the light of my study.
Dr Grainger does not claim that tropical deforestation is not occurring, as there is plenty of local evidence for that. But owing to the lack of frequent scientific monitoring, something for which he has campaigned for 25 years, we cannot use available data to track the long-term global trend in tropical forest area with great accuracy.
The picture is far more complicated than previously thought, he said. If there is no long-term net decline it suggests that deforestation is being accompanied by a lot of natural reforestation that we
|Contact: Simon Jenkins|
University of Leeds