The intensity of land-use influences the speed of regeneration in tropical rainforests, says new research. Tropical rainforests are a priority for biodiversity conservation; they are hotspots of endemism but also some of the most threatened global habitats. The Atlantic Forest stands out among tropical rainforests, hosting an estimated 8,000 species of endemic plants and more than 650 endemic vertebrates. However, only around 11 percent of these forests now remain. The quality of what remains is also a concern: 32 to 40 percent of remnants are small areas of secondary forest. Although the restoration of these secondary forests would go a long way toward mitigating the loss of forest cover and biodiversity elsewhere, it is not always possible to recover richness, diversity and floristic composition. Land-use history can make these changes irreversible.