London: The destruction of parts of the Brazilian Amazon has threatened scores of rare species doomed to disappear even if deforestation is halted, a new study has found.
The study, done by the scientists at Imperial College, London, has revealed that deforestation in Brazil has already claimed casualties, but the animals lost to date in the rainforest region are just a fifth of those that will slowly die out due to loss of habitat.
The researchers reached the bleak conclusion after creating a statistical model to calculate the Brazilian Amazon``s "extinction debt", or the number of species headed for extinction as a result of past deforestation. The model draws on historical deforestation rates and animal populations in 50 by 50 kilometers squares of land.
According to The Guardian, scientists have found that in parts of the eastern and southern Amazon, 30 years of concerted deforestation have shrunk viable living and breeding territories, which are enough to condemn 38 species to regional extinction in coming years, including 10 mammal, 20 bird and eight amphibian species.
The systematic clearance of trees from the Amazon forces wildlife into ever-smaller patches of ground, the report said.
Though few species are killed off directly in forest clearances, many face a slower death sentence as their breeding rates fall and competition for food becomes more intense.
“For now, the problem is along the arc of deforestation in the south and east where there is a long history of forest loss. But that is going to move in the future. We expect most of the species there to go extinct, and we``ll pick up more extinction debt along the big, paved highways which are now cutting into the heart of the Amazon,” Robert Ewers, co author of the study, said.
Writing in the journal Science, Ewers and his co-authors reconstructed extinction rates from 1970 to 2008, followed by forecast future extinction debts under four different scenarios, ranging from "business as usual" to a "strong reduction" in forest clearance, which required deforestation to slow down 80 percent by 2020.