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Growing threats to biodiversity 'arks'

Many of the world's tropical protected areas are struggling to sustain their biodiversity. This has been shown by a study just published in Nature by more than 200 scientists from around the world, including Mark-Oliver Rödel from the Museum für Naturkunde - Leibniz Institute for Research on Evolution and Biodiversity in Berlin. Mark-Oliver Rödel is a distinguished expert of the amphibians in West Africa.

The study's Principal Investigator, Professor William Laurance, from James Cook University in Cairns, Australia, and the Smithsonian Tropical Research Institute in Panama, said that "these 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."

Professor 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. The long-term experience of experts like Mark-Oliver Rödel was very helpful in this context. Laurance said the conclusion was that while most reserves were helping to protect their forests, about half were struggling to sustain their original biodiversity.

"The scariest thing about our findings," said 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." These 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 suffered encroachment from illegal colonists, hunters and loggers. Kadiri Serge Bobo of the University of Dschang in Cameroon, Africa, said that it was not just what was happening inside a reserve that was important. "Almost as important is what's going on outside it," he said. "Eighty-five percent of the reserves we studied lost some nearby forest cover over the past two to three decades, but 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 found 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," Ms Useche said.

The bottom line, the researchers say, is that a better job needs to be done in protecting the protected areas - and that means 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," said Professor Laurance, "tropical forests are the biologically richest real estate on the planet, and a lot of that biodiversity will vanish without good protected areas."

For further information contact:

Professor William Laurance James Cook University, Cairns, Queensland, Australia Email: bill.laurance@jcu.edu.au Phones: +61-7-4038-1518 and +61-7-4042-1819

Article details:

Laurance, William F., and 215 coauthors. 2012. Averting biodiversity collapse in tropical forest protected areas. Nature, DOI:10.1038/nature11318. Published online on 26 July 2012.

Contact at the Museum für Naturkunde in Berlin: Dr. Andreas Kunkel, Museum für Naturkunde, Tel. +49(0)30 2093 8690 Fax. +49(0)30 2093 8561, e-mail andreas.kunkel@mfn-berlin.de

idw :: 25.07.2012