Good in parts but very bad in others – that’s the ecological assessment of the massive fire that swept the northern slopes of Muizenberg and Steenberg mountains recently, burning across 800 hectares.
And the worst effects of the fire were in areas either still covered with dense stands of invasive alien vegetation, or where this vegetation had been cut and stacked but not yet burnt.
These areas included the government-owned land used by the SA Navy, from its Silvermine base up to the radio masts on top of Muizenberg mountain, and the surrounding area which was state land now being developed as the Stone Village residential estate by Tokyo Sexwale’s Mvelapanda group.
Senior Table Mountain National Park officials reminded the public that fynbos is a fire-dependant system that has evolved over thousands of years in conjunction with fires.
‘Those houses now have a firebreak’ But when a fire burns too hot – for example, when there is an excessive fuel load (amount of wood to burn) such as in stands of alien vegetation – fynbos’s mechanisms for coping with fire are less effective, or even totally inadequate.
“It’s not the fire that’s bad, it’s the heat,” explained Paddy Gordon, the park’s northern areas manager.
The area where the fire started – in Peck’s Valley off Boyes Drive above Muizenberg – consisted mostly of old veld that last burned in 1978.
“So that’s 26- or 27-year-old veld, and I would say the fire there was more beneficial than anything else,” said Philip Prins, the park’s co-ordinator of fire and technical services.
“But you get into trouble when you tell the people that a fire is a blessing in disguise!” he added.
‘We would have preferred to burn it ourselves’ Gavin Bell, the park’s southern area manager, commented: “You can say that it was a blessing in disguise there because those houses on Boyes Drive now have got a firebreak above them (that will be effective) for the next 10 years.”
But they acknowledged that the ash from the fire was a big nuisance for residents, and that if the city experiences sudden heavy downpours before the vegetation has a chance to re-establish itself, there could be some erosion.
Bell said there were also some patches of immature fynbos that had been burnt and where the plants were still too young to have produced and set seed – “So the fire in those areas was bad.”
The worst ecological damage from the fire was on areas of alien plant infestations and where such plants had been cut and stacked but not yet burnt.
And Gordon said that all the mechanisms that fynbos has developed to cope with fire over thousands of years – the various re-seeding and re-generation techniques – would not have been effective here because of the intense heat of the fire.
“So there was potential for huge destruction of the indigenous seedbank here, but also the stimulation of the alien invasive seedbank which can cope with a fire like this.
“Even in places where the fynbos may have been ready to burn, the temperature of this fire means that we’re probably going to find a greater re-growth and regeneration of alien plants, rather than fynbos.
“And while it wasn’t a bad thing that the old fynbos burnt, we would have preferred to burn it ourselves under controlled conditions, when there was more moisture in the air and a more favourable wind direction that would have taken the ash out to sea.”
Bell said there had been “quite a few” reports of steenbokkies fleeing from the fire on Ou Kaapseweg and Boyes Drive, but there had not been significant animal mortalities – “We’ve not seen huge numbers of carcasses lying around.
“There would have been porcupines and tortoises and snakes and other slower creatures, but animals have been in fynbos for thousands of years and while a few of them will have been burnt, a lot will have got away,” he said.
This article was originally published on page 5 of The Cape Argus on January 24, 2005