The government regularly granted logging concessions of less than ten years. Since it takes 30–35 years for a second-growth forest to mature, loggers had no incentive to replant. Compounding the error, flat royalties encouraged the loggers to remove only the most valuable species. A horrendous 40 percent of the harvestable lumber never left the forests but, having been damaged in the logging, rotted or was burned in place. The unsurprising result of these and related policies is that out of 17 million hectares of closed forests that flourished early in the century only 1.2 million remain today.Attribution of deforestation to population pressure or agricultural expansion was found not to be backed by existing evidence in a 1992 study. Subsequent research has shown that intensification of existing farmers and improved off-farm income reduced forest pressure. However, in some parts of the country forest encroachment still happens due to high demand for vegetables.
