With careful planning, areas of rainforest can he re-established, although it takes over a hundred years for the forest to return to its original state. However, it the land is damaged, only scrubby vegetation will grow again.
We all know it takes a long time for cleared rainforests to regenerate, but how long exactly? According to a study focusing on the Brazilian Atlantic forest, certain aspects can return surprisingly quickly – within 65 years. But for the landscape to truly regain its native identity takes a lot longer – up to 4000 years.
The Atlantic forest originally stretched along the southern half of Brazil’s Atlantic coast, covering some 1.2 million square kilometres. Once lush, the forest has been continually exploited for food, wood and space.
Today, land it used to occupy is home to most of the country’s population, including Brazil’s two largest cities, São Paulo and Rio de Janeiro, and only 100,000 square kilometres of forest remain. In 1993, however, the government created several protected areas to conserve the forest’s remnants. To determine how long it would take for the forest to regenerate, Marcia Marques and colleagues at the Federal University of Parana collected data on different parcels of forest that had been virtually cleared and left to recover for varying amounts of time.
The researchers looked at four different measures of forest regrowth: the proportion of tree species whose seeds are dispersed by animals, the proportion of species that can grow in shade, tree height, and the number of native species.
“Animal-dispersed trees sustain a large number of fruit-eating animals, that sustain other animals including large carnivores,” says Marques. “Thus, from the proportion of animal-dispersed trees we can estimate how complex the forest’s ecological web has become.”
Animals are key to the successful regeneration of cleared areas and, typically, 80% of the tree species in a mature tropical rainforest are animal-dispersed. The researchers found that it took just 65 years for a forest to recover to this level.
Picture Credit : Google