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Thursday, July 26, 2012

Half of the Reserves Biodiversity Threatened

A red-eyed treefrog
A red-eyed treefrog (Agalychnis callidryas) from Barro Colorado Island, Panama. This island, just 3700 acres in area, is one of the tropical protected areas evaluated in the study (photo © Christian Ziegler, Smithsonian Tropical Research Institute)
The impact of human activities that explore the tropical rain forest, by the rapid deforestation, lead to protected areas are increasingly threatened, biodiversity and ecosystem conservation also threatened. The low legal sanctions, as well as the weakness of the lead, is one of the causes of human daring exploit the forest haphazardly. As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity.

Published today in Nature, the survey by more than 200 scientists world-wide, including Monash University’s Dr Patrick Baker, assessed the health of 60 tropical reserves over a 20 to 30–year period and found that stressors such as habitat disruption, hunting and forest-product exploitation had taken a toll.

Lead author Professor William Laurance, of James Cook University and the Smithsonian Tropical Research Institute in Panama, said these reserves were like arks for biodiversity.

“Even though they are our best hope to sustain tropical forests and their amazing biodiversity in perpetuity, some of the arks are in danger of sinking,” Professor Laurance said.

They studied changes in biodiversity over the last 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions.

The result, about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them.

Dr Baker of Monash University’s School of Biological Sciences said that while many of the reserves had provided an effective haven for flora and fauna, around half had experienced declines in biodiversity.

“This is a serious concern because many of these reserves are among the last great wild places in the tropics,” Dr Baker said.

Dr Baker also said the degradation of areas surrounding the protected areas had negative effects on the health of the reserves themselves.

“Decline is a slippery slope. Once a reserve starts down that path, it is very hard to turn it around,” Dr Baker said.

The researchers concluded that if these arks are to withstand future threats, such as climate change, both their internal and external risks must be more effectively managed. Further, support for protected areas must be built among local communities.

“We have no choice. Tropical forests are the biologically richest real estate on the planet, and a lot of that biodiversity will vanish without good protected areas,” Professor Laurance said.

This article has edited by authors of threelas
Source: Monash
Publication: Nature