Tuesday, 5 February 2013

Destroyed fynbos ‘no ecological disaster’

Brian van Wilgen, of the CSIR s natural resources and environment department and Stellenbosch University s centre for invasion biology, says it s also too soon to confirm claims that the fires in places like the Wemmershoek mountains have caused an ecological disaster . Picture: Neil Baynes

Cape Town - Media reports that the latest wave of veld fires burning through the Western Cape have “destroyed” thousands of hectares of fynbos are simply not true, says leading fire ecologist Professor Brian van Wilgen.

And Van Wilgen, of the CSIR’s natural resources and environment department and Stellenbosch University’s centre for invasion biology, says it’s also too soon to confirm claims that the fires in places like the Wemmershoek mountains and the Cederberg have caused an “ecological disaster”.

Fynbos is a fire-adapted and fire-dependent vegetation type, he said. Regular fires are necessary to prevent plant senescence (growing old and declining) and to stimulate seed germination. “Without fire, there would be no fynbos – it’s as simple as that. The evidence is there for everyone to see,” he said.

Noting that mountains were still covered in fynbos, despite repeated fires in the past, he said: “There will be spectacular displays of mass flowering by bulbs and geophytes (plants with underground tubers or corms) in the coming spring.”

“By and large”, fynbos fires were not ecological disasters, he said, but he confirmed that fynbos could be damaged by too-frequent fires. This could now be happening in the province.

“There is a very real concern that fires are becoming too frequent. This could eliminate some of the long-lived shrubs, like proteas and leucadendrons, that need time between fires to build up new seed reserves. Normally, 12 years or so between fires should be sufficient. There is some evidence that fires are becoming more frequent than that, especially in areas close to large cities and towns – simply because there are more and more people who could start accidental fires.”

There was also evidence that the regional weather was becoming hotter and drier, and this increased fire opportunities, he added.

“Is this an ecological disaster? I reserve judgement on that, but I would call each fire that burns in the veld that last burnt less than 10 years ago ‘an ecological setback’.”

The other major cause for concern was that fires spread invasive alien trees and shrubs like pines and hakeas.

“Unless we can cut them down first so that they release their seeds and so that the subsequent fires can kill the seedlings.

“The recent fires would have burnt many areas infested with untreated alien plants. This too is an ecological setback – and if it happens several times in a row, I would call it an ecological disaster.”

Van Wilgen acknowledged that the fires could be an economic and social disaster for people whose houses were destroyed, livestock killed, and crops and plantations burnt down – “but such disasters are not ecological”.

There were strong arguments for investing in sound fire management through alien plant control combined with prescribed burning.

“We spend enormous amounts of money fighting wildfires. This would be more effectively spent on controlled burning if we are to reduce risks and eliminate disasters.”

- Cape Argus/IOL

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