Study: Extinction Debt Accumulated By Deforestation In Amazon

July 14th, 2012 BY VeganVerve | No Comments
Brazilian Rainforest

Tropical rainforests are home to a significant portion of the world’s biodiversity. The Amazon Rainforest in Brazil is no different, in fact Brazil is largely touted as the nation with the greatest biodiversity due to the rainforest. Overall, the Amazon is estimated to contain about ten percent of all species found on Earth. Unfortunately, this biodiversity has been and continues to be greatly threatened due to deforestation and other human activities.

Deforestation rates across the Amazon began being tracked approximately twenty-two years ago. Deforestation rates largely were high across Brazil for the majority of the tracking timeframe. However, in recent years deforestation began to drop. As of December 2010, deforestation was at its lowest in the recorded history.

However, between 2010 and 2011, deforestation rates were found to have drastically increased by approximately twenty-five percent. Some areas suffered deforestation more than others, especially those home to major soy and cattle farms. Overall, increased deforestation is attributed to the elevated demand for products popular for growth in Brazil, such as soybeans. Both cattle and soybean farming have been found to be the number one driver of deforestation in recent years.

While environmental groups and the government of Brazil have been attempting to resolve the deforestation issue, the future is uncertain. Recently changes to the Brazilian Forest Code were approved by Congress, although some aspects have reportedly been vetoed by President Dilma Rousseff. However, the changes would signal weaker protections for the rainforest, which could spell disaster for the future of the Brazilian Amazon.

Now a study recently published in the journal Science indicates that despite decades of severe deforestation, the full brunt of the effects have not yet been felt. According to the study, eighty to ninety percent of the species likely to go extinct due to deforestation in Brazil have not yet disappeared. The team of researchers determined the number of species likely to go extinct, based on ecological patterns in each section they broke the rainforest into, dating back to 1970. However, when the team compared their expected extinction numbers to what has occurred, the numbers were significantly different.

The so-called extinction debt is due to species not immediately perishing at the hands of deforestation but slowly becoming a smaller and smaller population over generations until finally they do disappear. Broken into individual thirty-one square miles, the segments the team studied were found to likely lose nine vertebrates and will see an additional sixteen extinction debts of vertebrates by 2050. Overall, even if deforestation stops today, extinctions will likely occur for thirty more years.

However, the researchers did indicate that the extinction debt lag time allows for changes to be made in order to save some of the species. Most pivotally the forest has a chance to be restored and protected in order to assure lower extinction rates than are expected.

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