South Africa Contemplates Letting Climate Change Take Its Course

By Laurie Goering

KRUGER NATIONAL PARK, South Africa – Something unexpected is happening in the grasslands of South Africa’s premier game reserve, forcing grazers like zebras and wildebeest to move out of some areas while tree-loving species like elephants and leopards move in.

The savannas, home to the continent’s great grazing herds, are starting to disappear, possible victims of global warming.

For the first time in eons, fast-increasing levels of carbon dioxide in the atmosphere seem to be giving shrubs and trees a competitive advantage over grass, leaving once-open areas vulnerable to encroaching vegetation.

Noting the invasion of underbrush with alarm, conservation scientists say climate change is presenting them with a new challenge: To adapt their thinking about an environment that is changing before their eyes. Long trained to protect intact ecosystems, they must now ponder once unthinkable questions, such as whether it is still appropriate to protect every species and manage every terrain, or whether the future of some plant and animal life should be left to the whims of a natural world in flux.

South Africa’s environmental rethink is part of a much bigger shift, an awareness of global warming that was given a dramatic jolt last month when former Vice President Al Gore was given the Nobel Peace Prize along with a U.N. panel.

Businesses, governments and people around the planet are searching for solutions to the vexing problems presented by climate change, including efforts to harness new technologies, accept daily lifestyle changes or, in the case of the African grasslands, reconsider long-standing beliefs.

“The whole idea of conservation is based around stasis, of things being the way they always were. But that’s not a tenable way of doing conservation in the future,” said Robert Scholes, a leading systems ecologist and climate specialist in South Africa, which is at the forefront of the international effort to rethink conservation’s mission.

With nature reorganizing itself around the world, “a relaxation of our very purist paradigms about conservation is almost certainly called for,” said Scholes, who works for South Africa’s Council for Scientific and Industrial Research.

In South Africa, researchers and park managers are racing to understand the changes underway in some of Africa’s best-known nature reserves and to come up with plans to deal with savannas that are quickly coming to resemble thickets more than open plains. What they discover and what they decide will likely guide a new international conservation ethic for an altered age.

“We’ve passed the point where we can avoid things being different,” said Barend Erasmus, a researcher on climate change and biodiversity at the University of the Witwatersrand in Johannesburg. But “I think we will know enough to do something. I think we can come up with good common-sense solutions.”

Small climate shifts already are having a dramatic effect on natural areas across the planet. In most places, some species are thriving in altered climate conditions while others falter, a process that is reshaping ecosystems. Butterflies, frogs, antelopes, flowers and other plants and animals are trying to migrate toward more suitable habitat, but many find their way blocked by the boundaries of existing parks or the sprawl of roads and cities.

Conservation officials, hoping to preserve as much biological diversity as possible, are talking about things they once dismissed as lunacy: gene banks, cloning and even “assisted migration” – loading plants and animals on trucks to help them get to new, more suitable habitats.

But worldwide recognition is growing that there are limits to what can be saved. A longtime focus on ensuring no species goes extinct is giving way among some leading scientists to an acceptance that thousands, if not tens of thousands, of species will likely succumb to climate shifts in coming years.

A key laboratory for this work and worry is Kruger National Park, a 240-mile-long finger of land along South Africa’s eastern border with Mozambique.

Kruger, one of the best-studied conservation areas in Africa, is home to Africa’s iconic Big Five – elephants, lions, leopards, Cape buffalo and rhinos – and draws more than 1.2 million visitors a year. The Wales-size park is also home to dozens of South African and international researchers, who over most of the last century have helped keep meticulous records on everything from the size of the park’s elephant population to the water quality of its rivers.

The park, unlike many in Africa, is intensively managed. Artificial watering holes help support game in some of the driest areas of the park, controlled fires are used to help weed out brush. Scientists in recent years have developed a management program for the reserve based on “thresholds of potential concern” – key rises or dips in animal and plant populations or things like river flow as an indicator of impending problems.

By that standard, Kruger already has some major worries. Water flow and quality are declining as development accelerates along the unprotected headwaters of the park’s main rivers. A growing elephant population is contributing to the loss of many of the reserve’s big trees.

But park managers in recent years have encountered a new problem as well: bush encroachment, or the invasion of Kruger’s open grasslands by woody shrubs and small trees.

In South Africa, fast-increasing levels of carbon dioxide in the atmosphere are giving an edge to shrubs and trees, which build their woody skeletons out of carbon, while pushing out savanna grasses, which many scientists believe evolved to live in a low carbon dioxide world. In parts of Kruger, slow-growing shrubs and small trees once kept in check by fire and hungry elephants are now shooting up in a tenth of the time it used to take them and turning open grasslands into thickets.

Whether those changes extend to the earth’s other savannas – a dominant ecosystem that today covers a fifth of the planet’s land surface – remains in question, because studies in many places have yet to begin or are not yet conclusive. But savannas from northern Australia to South America and the U.S. Midwest potentially could be similarly affected, said William Bond, a University of Cape Town botanist.

Not everyone agrees with Bond. Many scientists say while rising carbon dioxide in the atmosphere appears to favor trees, the advantages may be subtle or disappear altogether depending on other factors.

But if bush encroachment continues, managers at Kruger admit they may soon need to find a way to confront it, whether or not it is becoming “natural” in a transforming climate.

“Rangers who have been here a long time say it’s thicker, that Kruger is changing. Tourists complain they can’t see game like they used to, that all they see are thick curtains of bush,” said Stefanie Freitag-Ronaldson, science operations manager at Kruger.

“If by 2020 or 2050, what is natural is uniform thicket across Kruger, we might try to find a way to flout that,” added Harry Biggs, Kruger’s expert on adaptive biodiversity. “One of our values is the park should be natural. But what is natural is a hard question anymore.”

Kruger’s managers are gradually coming to accept that some of the coming changes may be unstoppable.

Most of the world’s conservation efforts over the last century have focused on setting aside key pieces of land to preserve ecosystems and help ensure no species goes extinct. But as the Earth’s climate changes, a growing flood of extinctions are inevitable, many scientists say.

Persuading governments and wildlife groups to abandon old ideas about conservation in favor of a new ethic won’t be easy. Kevin Rogers, a University of the Witwatersrand ecologist who helped write Kruger’s adaptive management plan, predicts the rise of a new era of “greenies and bunny huggers” virulently opposed to allowing species to slip into extinction. Even pragmatic nature lovers may wince at the idea that emblematic species like the blue crane – South Africa’s endangered national bird that nests in grasslands – may no longer have a place in an altered world.

Originally published by Chicago Tribune.

(c) 2007 Sunday Gazette – Mail; Charleston, W.V.. Provided by ProQuest Information and Learning. All rights Reserved.