Late summer in Cape Town and smoke hangs over Rondebosch Common. It’s the usual scene: flashing red lights, grim-faced firefighters, crowds of anxious onlookers. And me: jumping up and down like an over-excited kangaroo shouting “Let it burn! Let it burn!”
Of course there are casualties. Birds and insects can fly to escape the flames but terrestrial reptiles such as tortoises and snakes aren’t so lucky. And as for the plants, there is complete and utter devastation – barely a leaf is left.
But the fynbos life cycle begins the moment the flames have died down. And it starts with something you might not expect in a burnt and smoking landscape: an enormous dose of biomass is suddenly made available. And biomass is a fancy word for food.
In the first few minutes after a fire, anything obviously edible – a dead snake for example – is immediately picked up by yellow-billed kites (Milvus aegyptius). They get to a fynbos fire quicker than the emergency services and there were half a dozen in the air, wheeling in the smoke, when I arrived. White-necked ravens (Corvus albicollis) came the next day to pick over the pieces, joined by hovering black-shouldered kites (Elanus caeruleus) and jackal buzzards (Buteo rufofuscus), hoping to snare rodent survivors.
Several centuries ago, a post-fire Rondebosch Common would have soon been echoing to the snorts and grunts of large herbivores. Fresh greenery arrives little more than a week after the fire, attracting rhinos, antelope, zebra and hippo like a magnet; this was a favoured – and very simple – hunting technique used by the indigenous Khoisan: burn and wait.
And speaking of easy pickings, it’s not that long ago – perhaps 200 years – that a fynbos fire like this would have drawn humans too, foraging for conveniently-exposed food – mostly in the form of edible corms (something like a bulb) in the Iris family. Roasting was one way to prepare these corms – uintjies in Afrikaans (little onions) – so perhaps in this case people used to simply dust the sand off them and eat them right there and then – ready-roasted.
There are still foragers on the common today, albeit smaller ones. A few days after the fire I watched disciplined lines of ants carrying freshly-released fynbos seeds to their underground homes. There were also spider-hunting wasps (Hemipepsis) flying in slow, buzzy loops next to the fire-line, searching for fat-bodied spiders in the singed vegetation. The wasps are female and pregnant and will mercilessly attack the spider, paralysing it with her sting; the spider is then unceremoniously dragged it into a hole whereupon the wasp lays an egg on it and disappears, leaving the spider as warm food for the hatching wasp-grub.
Visitors to Rondebosch Common hoping for fields of flowers so soon after the fire will have to wait a few more months until the winter rains kick in. But there are a couple of oddities that bloom very quickly in the post-fire landscape. This is a strategy adopted by several fynbos plants, mostly underground specialists such as bulbs in the Amaryllis and Hyacinth families. It’s a risky move to grow and flower so early after a fire – the weather is still hot and dry, there are hungry survivors – but there’s no competition from other plants and you have all the remaining insects to yourself for pollination.
Most plants however are saving their flowers for later in the year; they have only one thing on their mind at the moment: growing.
Everywhere you look, there are fists of bright green leaves punching out of the sand while long trails of greenery weave across the ground like a snake. The recent fire was well-timed: it burned 40-year old fynbos that had become overgrown with alien grasses and dominated by drab shrubs; now there are rare Cape Flats fynbos plants on the go – Pelargoniums and sprawling Peas (Lotononsis) for example – species I hadn’t seen in that area before. Having lain dormant for decades as seeds under a dark layer of ancient vegetation, they were now benefitting from the sudden exposure to sunlight and were making up for lost time.
Trouble is, all the alien plants were enjoying the new conditions too. Make no mistake, the greatest threat to the bio-diversity of Rondebosch Common is the stuff we like to spread a blanket over and sit down for a sandwich on: grass – specifically alien grass species. Creeping across the common like a silent green tsunami, these fast-growing grasses are choking the common and will kill it far quicker than climate change or urban pollution. And although the alien plants disappear under the flames too, a short walk two weeks after the fire quickly reveals the inevitable: unwanted weeds, grasses and alien invaders lurking amongst the new fynbos seedlings.
But a fire gives us time to fight back. The immediate post-fire landscape is when measures can be taken to aid the recovery of the fynbos at the expense of the exotic stuff: easy things like pulling out newly-germinated alien seedlings (pine trees for example) as well as more complicated procedures like indigenous planting, the removal of burnt alien trees and spraying alien grasses with herbicides. Bio-diversity counts are easier at this time – you can see everything – and this adds to the incentive to protect and preserve: if people know what amazing botanical jewels exist on their doorstep, they are more inclined to walk on it, enjoy it and keep it.
And with what’s waiting in store for us – botanically – after the rains, Rondebosch Common is something worth keeping indeed; stand by for the show.