Biodiversity Decline in Tropical Wildlife Reserves More Destructive Than Climate Change: Study

Scientists have found that the things happening around rainforest preserves and refuges are affecting what goes on inside them, and that at least half are degrading as a result of human activity in the vicinity.

Scientists in the journal Nature have released yet another study full of dire predictions. This study analyzed ecological data from protected reserves in 36 tropical countries,the British Independent reported on July 27, and found that half of the reserves are showing the effects of what is happening outside their borders.

Moreover, one of the researchers told Bloomberg, the resulting changes are even more marked than those resulting from climate change.

In the largest ever study of its kind, more than 200 scientists undertook a five-year analysis of data related to the reserves and mapped out the changes that had taken place in major tropical species groups over the past two to three decades, the Independent reported.

"These reserves are like arks for biodiversity, but some of the arks are in danger of sinking even though they are at best hope to sustain tropical forests and their amazing biodiversity," said Professor Bill Laurance of the James Cook University in Cairns, Australia, according to the Independent. "Tropical forests are the biologically richest real estate on the planet and they're rapidly falling before the bulldozer and chainsaw. Protected areas are quickly becoming the final refuges for many species and ecosystems and we need to know if they're going to do their job of preserving tropical nature.”

No animal was too big to be immune, Laurance told the British newspaper. Everything from tigers and jaguars, to elephants and primates, to freshwater fish, old-growth trees and exotic plants showed effects, he said. Half the reserves studied were “suffering,” he said, while the other half were doing okay.

"Among the suffering reserves, it's striking how sweeping the declines in biodiversity tend to be,” Laurance said. “It's not just one or a few groups but whole suites of forest-dependent species that are declining.”

Such concerns would seem to echo what has already been said in other contexts. Just before the climate-change meeting in Rio de Janeiro, Brazil, the United Nations warned that the earth was at or near a tipping point, after which no amount of environmental remediation could restore that which has been lost to industrialization and development. The Rainforest Alliance and other groups raise similar alarms.

“Thus far, our human family has erased half of our original endowment of tropical forests. Our world is now facing the greatest extinction crisis since the fall of the dinosaurs 65 million years ago,” the Rainforest Alliance says on its website. “The future of over 50 percent of Earth's plants and animals—and hundreds of human cultures—will be determined within the next few decades. Since our lives are so dependent on the forest's bounty, our future is at stake as well.

Laurance called the rate of decline “flat-out scary” and said that rainforest diversity inside and outside reserves faces “profound threats as their surrounding lands are being hit by a tidal wave of logging, fires and intensive human land-use.”

The data indicate that simply putting aside lands for preservation of wildlife and fauna is not enough, the study’s authors surmised.

“Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health,” the study’s authors wrote in the abstract. “These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.”