Famed biologist Daniel Janzen once proclaimed, “No park is an island.” What Janzen meant is that the isolation of a park is corrosive for its ecology and deadly for its biodiversity.
The natural movements of species across landscapes are as essential to life as the flows of wind and water. But such movements are being stymied as parks and protected areas become increasingly isolated from their surrounding natural habitats—thanks to the ever-expanding footprint of agriculture, infrastructure, and other human activities.
Isolated protected areas lack the gene flow and demographic stability that arise from wildlife movement. As a result, they can become “extinction vortices” for vulnerable species—areas where small population sizes, inbreeding, losses to poachers and encroachers, and high mortality in surrounding modified habitats collectively conspire to drive species to local extinction.
Indonesia’s Palm Oil
A massive worry is Indonesia—where species are plummeting toward extinction twice as fast as almost anywhere else. Sprawling agribusiness crops, such as palm-oil plantations, create oceans of monocultures that are hostile to most native species.
Borneo’s oil palm plantations have lost up to 90 percent of their mammal diversity, and plant biodiversity has slumped to almost zero. Nearly all of the biodiversity in oil-palm landscapes survives only in small fragments of native forest, which harbor some forest-dependent species.
Sustainability certification is trying to conserve these critical fragments. For instance, corporations and smallholders that have joined the Roundtable on Sustainable Palm Oil are being urged to set aside habitats with “High Conservation Value” if they wish to be certified as sustainable.
Such efforts are important but far from adequate. In Borneo, most High Conservation Value habitats are themselves highly degraded, with just one-fifth still being fully forested. Forest-dependent species will be highly vulnerable in such wounded landscapes.
Hence, oil palm is taking a giant bite out of biodiversity and the practical measures being used to limit its burgeoning impacts are marginal at best.
Can wildlife corridors help to link protected areas and thereby reduce extinction vortices? A study of fishers—a predatory mammal similar to the wolverine—across Alberta, Canada found that protected areas alone had little effect on their movements.
Rather than stay in a single protected area, fishers used corridors of native vegetation to move across the landscape and exploit a variety of different areas for survival. This implies that protected areas alone can’t sustain vulnerable species, if we ignore environmental disruption in lands surrounding the protected areas.
Such insights underscore the limitations of voluntary guidelines—such as Aichi Target 11, which asserts that 17 percent of a country’s terrestrial habitats should be protected. Such metrics provide simple guideposts for conservation, but fail to emphasize that the ecological integrity of habitats surrounding protected areas is often as crucial for wildlife as the protected areas themselves.
Eye of the Storm: Australia
Australia has the worst historical extinction record of any nation on Earth—and its recent political record suggests the situation is only worsening.
One problem is that Australia’s national parks are largely in residual locations—places that weren’t useful for anything else. Even these marginal areas are now fair game for shooting, development, and livestock grazing during droughts.
At present, land-clearing rates in Australia are among the highest in the world. Conservative politicians have disbanded a Ministerial Council that oversaw Australia’s Biodiversity Conservation Strategy from 2010 to 2030.
And Australia’s efforts to counter forest loss are paltry. For example, a flagship program to plant 20 Million Trees is grossly inadequate when compared to the 400 million trees being cleared each year in the state of Queensland alone.
With its increasingly glaring conservation weaknesses, Australia has rightly fallen in the eyes of the world. It’s time for Australia to return to the vanguard of global conservation thinking—and to advocate the critical role of connectivity in sustaining nature and environmental quality.