Earth & Environment - Posted by Cynthia Lee-McGill on Wednesday, July 25, 2012 16:04 - 2 Comments
Biodiversity reserves ‘in danger of sinking’
MCGILL (CAN) / DUKE (US)— Many of the world’s tropical protected areas—the biologically richest ecosystems on Earth—are struggling to sustain their biodiversity.
More than 200 scientists from around the world, including Professor Colin Chapman of McGill University, report the findings in the journal Nature.
Straight from the Source
“Reserves are like arks for biodiversity, but some of the arks are in danger of sinking, even though they are our best hope to sustain tropical forests and their amazing biodiversity in perpetuity,” says lead author Professor William Laurance, of James Cook University in Cairns, Australia, and the Smithsonian Tropical Research Institute in Panama.
Laurance and his team studied more than 30 different categories of species—from trees and butterflies to primates and large predators—within protected areas across the tropical Americas, Africa, and Asia-Pacific.
They estimated how these groups had changed in numbers over the past two to three decades, while identifying environmental changes that might threaten the reserves.
“Our research is particularly alarming because the conservation community has relied on parks and reserves as the primary tool to protect the biodiversity of the tropics. The scale of the threat is highlighted by the fact that the only primate species that is believed to have gone extinct in the 20th century did so despite occurring in large national parks,” says Chapman, Chair in Primate Ecology and Conservation, and study co-author.
While most reserves were helping to protect their forests, about half were struggling to sustain their original biodiversity. “The scariest thing about our findings,” says Carolina Useche, of the Humboldt Institute in Colombia, “is just how widespread the declines of species are in the suffering reserves. It’s not just a few groups that are hurting, but an alarmingly wide array of species.”
The declines included big predators and other large-bodied animals, many primates, old-growth trees, and stream-dwelling fish and amphibians, among others.
The researchers found that reserves that were suffering most were those that were poorly protected and faced encroachment from illegal colonists, hunters, and loggers.
Eighty-five percent of the reserves studied lost some nearby forest cover over the past two to three decades, and only two percent saw an increase in surrounding forest. Deforestation is advancing rapidly in tropical nations and most reserves are losing some or all of their surrounding forest.
The team concludes that many nature reserves acted like mirrors—partially reflecting the threats and changes in their surrounding landscapes. “For example, if a park has a lot of fires and illegal mining around it, those same threats can also penetrate inside it, to some degree,” Useche says.
This is particularly alarming because the most endangered species are found in protected areas occurring in highly degraded landscapes, which implies that we may be facing a wave of extinctions in the near future.
The authors conclude that a better job needs to be done in protecting the protected areas—by fighting both their internal and external threats, and building support for protected areas among local communities. Such efforts will help ensure protected areas are more resilient to future threats such as climate change.
“We have no choice,” says Laurance, “tropical forests are the biologically richest real estate on the planet, and a lot of that biodiversity will vanish without good protected areas.”
Additional co-authors of the study contributed from Duke University, McGill University, University of Pennsylvania, Yale University, Monash University, University of Texas at Austin, Stanford University, University of Leeds, University of Washington, University of Southern California, Rice University, Texas A&M University, and Stony Brook University, among others.
More news from McGill University: www.mcgill.ca/newsroom/