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Sunday, September 1, 2013

Sound ecosystem science should drive conservation

In the mid 19th century the Ahwahneechee, a Native American tribe, was forcefully expelled from the Yosemite Valley a landscape, which they had inhabited for over 200 generations. In October 1890, Yosemite became a national park. This was the birth of the Yosemite model of wildlife conservation. Like other American inventions, the Yosemite model has been promoted with zeal across the world.

Over the past century African governments, often enabled by European and North American wilderness romantics, have established over 1100 enclaves of protected areas; national parks and reserves, which play an essential role in sequestering wildlife and core habitat components from grubby human hands.

It is phenomenally admirable that total protected-area coverage in Africa has increased nearly two-fold since 1970, and now cover circa 3.1 million square kilometers. Although the expansion of protected areas over the last four decades is heartening their ability to maintain viable populations of diverse wildlife species, over the long-term, is now threatened by a combination of human-induced or anthropogenic factors, including naked greed and natural factors, including climate change.

The effect of reserve isolation and insularization on wildlife diversity and abundance is now grabbing significant attention. Across Africa agriculture land, urbanization and roads have chocked dispersal areas and migratory corridors that hitherto enabled seasonal dispersal of wildlife across contiguous requisite habitats. Today wildlife is sequestered and trapped in islands, parks and reserves, which lack the requisite habitat resources – water, vegetation, prey and refugia – to support viable populations, especially of large mammals and associated predators.

Long-term data for 69 large mammal species from 78 protected areas in Africa revealed a 59 percent decline in large mammal population between 1970 and 2005. The impact of habitat loss on wildlife populations is well documented in the Maasai Mara ecosystem. When wheat cultivation in the Mara ecosystem expanded from about 4,900 hectares to over 50,000 hectares between 1970 and 19990, the total population of migratory large mammals declined by circa 58 percent.

A recent study by J. Ogutu et al., published in the Journal of Zoology analyzed trends in populations of seven ungulate species in Maasai Mara between 1989 and 2003 based on monthly monitoring using vehicle ground counts. The study revealed that the abundance of six of the seven ungulate species declined markedly and persistently in the reserve over the fifteen-year period. According to the study the declines happened simultaneously with habitat degradation, land use change in adjacent pastoral ranches, recurrent severe droughts and an exceptional El Nino flood in 1997/1998.

Are the chickens coming home to roost? Is the paradox at the heart of the Yosemite model of conservation unraveling? In the face of irrevocable human induced land use transformation and greed – urbanization, agricultural expansion, infrastructure development and poaching as well the impact of climate change on habitat quality – I am persuaded that a model of conservation based on the romantic pre-human wilderness model has run its course. We must re-imagine a new conservation model for a crowded planet, where majestic parks of yesteryears have become glorified zoos.

I argue that a post-modern construct of conservation must re-examine the Yosemite model of conservation predicated on the bizarre notion of isolated patches of undisturbed wilderness, apart from humans. Such a notion has no basis in sound ecosystem science. Conservation must embrace a whole landscape based approach in which diverse wildlife species and natural habitats are interconnected, resilient and integrated with compatible human land use.

Connectivity among protected areas will enable and sustain dynamic interactions among species and enable utilization of ecological resources across large spatial scales, taking advantage of seasonal variability of habitat resources. The challenge lies in negotiating access and incentivizing change of user or buying back wildlife migration corridors or dispersal areas currently under private ownership and incompatible use.

There is a great opportunity here to create the largest and most lucrative ecosystem service market on the planet. Landowners could be persuaded using financial incentives to individuals or associations of landowners to offer their land for use as wildlife migration corridors. The ecosystem service market could be developed further to enable trading of such leases in national and international stock markets.

For the large and wide ranging mammals like the elephant, which are already under intense human predation pressure, range constriction and decline in habitat quality could trigger catastrophic population collapse and extinction. Lack of good ecosystem science, not poaching, is the greatest long-term threat to our wildlife.

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