A red-eyed tree frog (Agalychnis callidryas) from Barro Colorado Island in Panama. This small island, just 1500 ha (3700 acres) in area, is one of the tropical protected areas evaluated in this study (photo © Christian Ziegler <[email protected]>, Smithsonian Tropical Research Institute). Note: It is prohibited for any third party or agency to use or license this image; any use other then described above shall be subject to usage fees as determined solely by the photographer.
Much of conservation science boils down to good decision making: when, where and how we ‘set aside’ terrestrial or marine areas for specific protection against the ravages of human endeavour. This is the basis for the entire sub-discipline of conservation planning and prioritisation, and features prominantly in most aspects of applied conservation and restoration.
In other words, we do all this science to determine where we should emplace protected areas, lobby for getting more land and sea set aside so that we have ‘representative’ amounts (i.e., to prevent extinctions), and argue over the best way to manage these areas once established.
But what if this pinnacle of conservation achievement is itself under threat? What if many of our protected areas are struggling to insure biodiversity against human consumption? Well, it’d be a scary prospect, to say the least.
Think of it this way. We buy insurance policies to buffer our investments against tragedy; this applies to everything from our houses, worldly possessions, cars, livestock, health, to forest carbon stores. We buy the policies to give us peace of mind that in the event of a disaster, we’ll be bailed out of the mess with a much-needed cash injection. But what if following the disaster we learn that the policy is no good? What if there isn’t enough pay-out to fix the mess?
In biodiversity conservation, our ‘insurance’ is largely provided by protected areas. We believe that come what may, at least in these (relatively) rare places, biodiversity will persist despite our relentless consumerism.
Unfortunately, what we believe isn’t necessarily true.
Today I’m both proud and alarmed to present our latest research on the performance of tropical protected areas around the world. Published online in Nature this morning (evening, for you Europeans) is the 216-author (yes, that is correct – 216 of us) paper entitled “Averting biodiversity collapse in tropical forest protected areas” led by Bill Laurance.
Using data derived mainly from exhaustive expert interviews (hence the long co-author list) and validated with real time-series data, we looked at 31 functional groups of species (e.g., big predators, raptors, rodents, dung beetles, lianas & vines, etc.) in 60 tropical protected areas across Asia, Africa and the Americas to see whether they had remained stable, increased or decreased in abundance over the last 20 or 30 years.
With these data, we constructed a ‘reserve-health index’, which showed that about half of the 60 protected areas we examined weren’t doing terribly well (i.e., they were in poor biodiversity ‘health’). Of course, this also means that about half of the reserves were doing reasonably well at protecting their biodiversity.
Perhaps not all that surprisingly for unprotected habitats, the species groups known to be sensitive to change (e.g., big predators and other large-bodied animals, many primates, old-growth trees, and stream-dwelling fish and amphibians) were declining in the ‘poor-health’ reserves (in fact, about 20 of the guilds have been declining), and those known to respond favourably to disturbance (e.g., diseases, lianas & vines, exotic species) have been increasing.
How could all this be happening in so many of our protected areas and parks?
Well, we looked at the drivers, too. Parks with active on-the-ground management over the last 30 years to fight things such as invasive species, fire and deforestation, certainly did better; if there ever was a better justification for investing in protected area management, I’m unaware of it.
More importantly though, we found that the land-use changes outside the protected areas were ultimately responsible for their health. If the region surrounding a protected area had suffered from high deforestation, mining, illegal human colonists and hunting, then the chances were higher that the biodiversity within was declining.
In other words, protected areas do not act as islands buffered from the sea of degradation surrounding them. What we do around them, we do to them to a large degree.
Although we only had only one datum from Australia in our sample (Mt. Spec in Paluma Range National Park, north Queensland), the trends we observed are indeed occurring broadly across our tropics as well. Our largest national park, Kakadu, is a particularly good example of a struggling protected area. The region as a whole is rife with feral animals, the bushfire burning frequency is too high, and the lack of coordinated, regional-scale management is making matters worse.
Now, I know what some of the more spiteful libertarians might think that because so many protected areas are struggling to conserve the biodiversity they were created to protect, we should abandon the idea and let development proceed uninhibited. Of course, that is (as is typical of the libertarian) a monstrously stupid idea.
We showed that with active management and a history of lighter environmental footprints surrounding protected areas, tropical protected areas do just fine. Globally, we still have a huge gap between the areas now protected and what should be protected, and our policies surrounding the interstitial habitats between protected areas is way too lax. If we continue to add protected areas and manage them and their surrounds well, we’ll be successful at protecting a good component of our biodiversity.
Let’s hope we can continue to improve.
Finally, I’ll leave you with a little video interview promo Bill and I did up (thanks to Mike ‘Fang’ Seyfang) a few weeks ago in preparation for the paper’s online appearance. It is a little teaser for the paper, with a full video interview coming online later.
I’m sure Bill will be going guns with the media today, and I’m available for comment too (although I’m overseas at the moment).
CJA Bradshaw
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