/ 21 January 2000

Blame it on the weeds

Dense uncontrolled alien vegetation fuelled the flames which scarred the Cape Peninsula this week.

As the worst fires in decades ravaged the area, scientists blamed vast tracts of alien vegetation for the scope of the inferno in the current dry, hot and windy conditions.

It has proven a combustible mix. From Noordhoek, Kommetjie and Hout Bay along the Atlantic Ocean to Glencairn and Simon’s Town in False Bay and inland to Constantia, huge areas of land have been scorched.

“The fire has gone into areas which should not have burnt,” said Professor Richard Cowling, director of the Institute for Plant Conservation at the University of Cape Town. “Some areas have burnt which are going to create problems in the future, particularly erosion.”

The “chief nasties” feeding the flames were pines, bluegum trees, Australian wattles, myrtles and hakeas, a Protea-type shrub from Australia. This alien vegetation burns more easily than the local trees.

In the intense heat at Rooi Krans near Scarborough, for example, every seed in the topsoil has burnt. It will take a long time to recover.

“The peninsula will not be a happy place to look at for at least the next six months,” Cowling added.

Over the past week more than 6E000ha, or 20%, of the protected nature reserve, has been obliterated. Although much of the world-famous fynbos has been destroyed, experts said this was not necessarily a bad thing.

“Fynbos thrives on fire,” said Cowling. “It’s good to burn if it has reached an age of more than eight years.” But the problem is that the burning happened in concentrated areas – and in those areas, all of the fynbos was wiped out.

Although the focus remains on completely extinguishing the fires, the long-term consequences are likely to be a headache for conservation officials and the provincial purse. Cowling said it is crucial for conservation officials to go in after the fire to remove the alien vegetation.

A system of block burning – controlled burning of patches of vegetation as firebreaks – is necessary to ensure effective conservation management and fire prevention across the peninsula.

Cape Peninsula National Park officials say they had already removed alien vegetation from a few thousand hectares and had secured international funding for further eradication when the fires hit.

The only area where block burning has been done regularly is around Cape Point. In other areas the practice had fallen behind.

Park representative Stephen Hulbert said it would be a great challenge for officials to raise the cash and find the staff to remove new alien vegetation in the burnt- down areas.

But conservation officials’ work is not made easier as people build homes high up on the mountains, often too close to the alien vegetation. In other cases homeowners do not adequately protect themselves against fire.

One thatch-roof house in the middle of the inferno has been built just metres from dense alien vegetation without a firebreak. Although there are water sprinklers on the roof, any moderately strong south-east wind blows the water away.

“The big issue is that this is a fire-prone environment and that people should learn to live within these constraints,” said Cowling. “We are going back to sleep again whereas we actually need to institute a system of block burning … landowners must get wise and chop out [alien vegetation].”