Blazes are crucial for Cape Floral Kingdom
SOME Capetonians have described the peninsula’s burnt fynbos areas as “devastated” or “a moonscape” – but fynbos experts describe it as a good, clean-burnt area crucial for the regeneration of the veld.
Fynbos is one of the oldest vegetation types, thousands of years old and has evolved to be dependent on fire. Without it, it would eventually die out.
More correctly called the Cape Floral Kingdom, it is the smallest of the six floral kingdoms in the world and home to an extraordinary 9 000 plant species. Of these, 69 percent occur nowhere else in the world.
Conservation authorities say this places an obligation on the country to ensure its survival. Fynbos also has an economic value of about R77 million a year from ecotourism and harvesting of wild flowers.
Fynbos expert Jan Vlok said last week’s fires, which burnt 6 900ha of 15-year-old fynbos, came at exactly the right time. Earlier than 15 years would have been detrimental for some plants and later than 20 years would have meant some plants had already become moribund. It was a “hot burn” – a fire that burnt fast, taking almost everything in its path – which is what the veld needed.
“It was a high-intensity, clean burn. It burnt everything, except plants with stems thicker than 2cm. Around 99 percent of fynbos is absolutely dependent on fire. It triggers a whole lot of species to germinate. Even smoke itself triggers germination,” Vlok said.
Other benefits of a hot fire are that it burns all the leaf litter, so it kills pathogens, like fungi, that are harmful to fynbos; it opens up space for plants to germinate; and nutrients like phosphates are released in the ash.
“If you have these constant piffling winter burns, it does not get rid of the leaf litter and also doesn’t get rid of the rodents. This is important because rodents have a high predation rate on seeds, so they need to be kept in check.”
Vlok says a fynbos fire driven by high winds moves rapidly and is at any one area for only 10 to 15 seconds. This will kill some animals, but the soil temperature just 2cm below the surface remains normal so animals that burrow can survive, while others can escape for those 15 seconds in cracks and crevices.
Research shows that the rodents that survive leave the burnt area as it is too exposed to predators. Nocturnal rodents tend to stick around as they have the benefit of the cover of darkness.
Tortoises will die but their eggs, buried underground, will survive.
Fynbos seeds, many of which are taken underground by ants, can stay in the soil for many years until they germinate. Others, like those of proteas, are stored on the plant in cones until a fire comes through and the proteas release them.
“But the problem is, this also happens with the seeds of aliens. After a fire they pop up like hair on a dog’s back.
“That’s going to be a big problem,” said Vlok.
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