From climate change to berg winds and alien vegetation, it appears the recent devastating Cape Town fires have been attributed to a number of factors.
This begs the question whether the intensity of the fires will become a norm in the Cape and elsewhere in South Africa.
On Sunday when Cape Town’s fires started, South African National Parks (SANParks) fire manager Philip Prins told The Citizen the South African Weather Service flagged it as an “orange day” – when careful note should be taken of any signs of smoke and that any fires must be attacked with “maximum force at hand”.
The reason for this is because Sunday 18 April was unseasonably hot, with several weather stations recording temperatures up to 17 degrees higher than the average temperatures at this time of year.
There was also a north-easterly berg wind blowing at the time of the fire.
“This is not a once-off event, but part of a trend that has been observed in the past decade,” Prins said.
The Table Mountain National Park (TMNP) has an initial fire attack success rate of 95%. Fires in the park are typically contained within the first 90 minutes.
But this fire seemed to burn out of control at a a rate faster than firefighters were able to quell.
Prins said increased temperatures are attributed to climate change, which is associated with more extreme weather events such as heat waves and floods.
“Hotter temperatures and more variable rainfall will certainly create more frequent conditions suitable for wildfires and also make it more difficult to contain and extinguish wildfires. So far, we have had a very dry and warm autumn period, which exacerbates the effects of fires that do occur.”
A popular conclusion drawn whenever there is a fire in Cape Town is that alien vegetation is to blame. Alien plants increase fire intensity and make it more difficult to contain and extinguish.
But Prins said TMNP was making concerted efforts to reduce the impact of alien species in the park. Some R165 million has been spent in the past 10 years to treat 113,000 hectares of land and created 204 jobs.
The most recent fires destroyed more than 600 hectares of biodiversity area.
“’Stockpiles of alien plants referred to as stacks are usually burnt during the colder and wetter months of the year. TMNP is conducting stack burning or fuel reduction burning on an annual basis and these burns can only take place once an open burning permit has been issued by the city of Cape Town.”
The north-easterly breeze coupled with the fire moving towards pine trees saw numerous spot fires crop up.
Prints said this caused the fire to spread more rapidly in a southerly direction, also due to the wind and slope of the mountain. Another factor was the spotting of fire embers.
“Also, the heat from the fires create its own wind system and this can lead to very strange weather effects and wildfire behaviour.”
Were flora and fauna affected?
TMNP head of conservation Dr Luthando Dziba said much of the park’s plants, namely fynbos and renosterveld, are adapted for fires. In fact, fires form an important part of many plant species’ life cycles, Dziba said.
“As part of this natural cycle, smoke and heat from fires stimulate plants to release their seeds or stimulate seeds to germinate. Some species also resprout after a fire.”
However, if fires occur too frequently, this can stimulate the growth of invasive species. Animals too have adapted to fire, many of which will run away when they smell smoke.
The TMNP is an urban park, but does not have many fences in order to better facilitate wildlife corridors and animal movement.
But slow-moving species such as tortoises are bound to be killed in fires. Even these species have adapted, with Dziba saying they now lay their eggs underground so that even if the adults die, the eggs are able to start a new generation.
Department of Forestry, Fisheries and the Environment Minister Barbara Creecy plans to visit the TMNP on Saturday.
The extent of the damage is still being determined by authorities.