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Ecological burns are different from wildfires

Fire lilies grow on the slopes of Table Mountain after harsh fires. Picture: Andrew Ingram.

Fire lilies grow on the slopes of Table Mountain after harsh fires. Picture: Andrew Ingram.

Published Jan 15, 2022


As the City of Cape Town’s biodiversity conducts burns at various nature reserves, experts underlined the importance of ecological burns

Cape Town - As this year’s eco-burning season gets under way with the City of Cape Town’s biodiversity management team conducting burns at various nature reserves, experts have underlined the importance of ecological burns and why they are different from wildfires.

With several approved potential ecological burns at Table Bay Nature Reserve, the Parklands Fynbos Corridor, and Blaauwberg Nature Reserve, Cape Nature General Manager Petro van Rhyn said that ecological burns were used to manage either fuel loads on properties, or to burn veld that is very old and needs rejuvenation.

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“As with humans, veld that becomes old (moribund) also becomes less fertile (senescent) as the plants in that veld cannot reproduce any more. Something needs to happen to rid the veld of the old species and bring in the younger, more ’virile’ generation.”

“Fynbos fire is that driver that maintains the delicate balance of the ratio between young, medium, and old veld. Ecological burns are a means to this end. In the past, CapeNature and other land managers used ecological burns more often than today. The prime reason for this is that so many uncontrolled fires are occurring, so the veld doesn’t have to reach old age,” van Rhyn said

“In other words, we are responding to fires reactively and not protectively. A healthy reserve or veld community needs old veld, young veld, and middle aged veld. Using the human analogy again, having a population that is too young or too old is not ideal as it becomes unstable.”

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Given that higher temperatures, unstable weather and climate patterns all affect the balance of the veld, biodiversity area manager at the Blaauwberg Nature Reserve, Koos Retief said that fire plays an important role in the management and maintenance of nature reserves in the Cape, especially in very small urban nature reserves.

“Nature reserves in the Cape Floristic Region (CFR) need to be considered as part of a larger landscape which is closely associated with fire. The regeneration of many ecosystems in the CFR, such as a range of fynbos and renosterveld vegetation types, is driven by fire events. I

“Indigenous animal populations in the Cape require access to new plant material for forage. However, many indigenous plant species cannot regenerate as seedlings unless thick stands of old vegetation are opened up,” said Retief.

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“A lack of fire in natural landscapes can lead to the accumulation of large amounts of flammable timber over time, especially in areas that have been invaded by non-native plants. This could result in very intense, large-scale wildfires that could have disastrous effects on infrastructure and people.“

“One of the objectives of conducting ecological burns is, therefore, to attempt to manage fires under controlled conditions rather than having to scramble firefighting resources to respond to wildfire disasters.

“The implementation of ecological "block" burns can also promote a more diverse landscape with a mosaic pattern of vegetation patches of different veld ages, rather than a single large wildfire that resets the whole landscape to one veld age,” Retief added.

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The City’s deputy mayor and mayco member for spatial planning and environment, Eddie Andrews stressed that it was important to note that ecological burns are planned burns unlike wildfires.

“Wildfires are uncontrolled and happen accidentally, spontaneously like by lightning, arson, and so forth. This is not covered by ecological burns. That’s why the city informs residents adjacent to ecological burns before the operation takes place. Weather conditions for ecological burns are selected with wind to carry smoke away from residential areas as much as possible,” said Andrews.

“The Environmental Resource Management (ERM) Department works with the Fire and Rescue Service to ensure that the procedure is conducted efficiently and safely. Thus, carefully managed ecological burns conducted in conducive weather conditions, are vital to the preservation of natural vegetation and reduce the fire as well.”

"Hence any resident witnessing a wildfire starting or burning should report it as soon as possible by phoning 107 or 021 480 7700 from a cell phone," added Andrews.

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