Featherbed Co. remains not only committed to restoring the natural habitat at Featherbed after the savage destruction left in the wake of the Knysna Fires of 2017 but also to prevent that horror from happening again.
The extent of the damage
The fires that swept through the Garden Route, raged for about ten days from the 7th of June 2017, destroyed almost 20,000 hectares of the region, and at Featherbed, reduced most of the vegetation to ashes.
Aerial photos of the reserve taken in the days after the smoke cleared, reveal a largely charred landscape with only a few small portions of indigenous forest left standing above Needle Point and Coffin Bay, as well as the forest above the site where our restaurant had stood. (This came as no surprise: multi-species, evergreen, indigenous forests are always the most fire-resistant of habitats in the regions where they occur.)
It was estimated that 95% of the reserve had been burned - this included most of our visitor facilities.
Featherbed Co. closed for business in order to rebuild - a process that took eighteen months.
New shoots
Within weeks of the inferno, we started noticing new seedlings sprouting! Needless to say, we were delighted.
But it wasn’t all good news: in large areas of the reserve, the greatest number of seedlings that were germinating were those of the Rooikrans or Red-eye Wattle (Acacia cyclops), which is an invasive alien that’s a particular threat to the fynbos of the Western Cape Province. Rooikrans was brought from Australia to Cape Town back in the 1830s to stabilise the sand dunes of the Cape Flats, but, with no natural enemies in this country, every one of the many seeds they produced became viable, and the species began colonising large areas that had previously been covered by fynbos (Cape heathland or Cape macchia). The Rooikrans had spread to the Garden Route by the middle of the 20th Century, and by the ‘70s and ‘80s, even places as remote and protected as Featherbed Nature Reserve had been colonised.
Although we began following a programme of cutting down as many Rooikrans as we could in the early 80s, the invasion proved almost too much of a challenge - so the fires came as something of a mixed blessing: while they killed almost all the old Rooikrans, they also burned the fynbos that had survived despite the onslaught of the invasive aliens.
Professional team
Good rains after the fires encouraged the germination of all kinds of plants - indigenous as well as exotic - but the speed with which the Rooikrans were sprouting was alarming. So, despite the fact that we have always taken advice from qualified and locally knowledgeable environmental consultants, we decided that we needed to employ a full-time team on-site to help us get Featherbed back rehabilitated.
This team included a qualified horticulturist with many years experience of in the reserve and the Garden Route, as well as 14 labourers, who came to us with no knowledge or experience of the work they would need to do. Our hort and his ‘Aliens Team’ began their work about six months after the fires. (Yes, hort. It’s the nickname horticulturists around the world have adopted for themselves). Six months after the burn was just the right time for the team to begin its work - because by now (mid-summer) the seedlings had reached a workable size, and they were thus both easy to identify, even from a distance, and easy to grip and remove.
Weeding
In essence, the team’s job - at first - was to go over every inch of the reserve that they could get to, and to pull the Rooikrans saplings out of the ground, roots and all. By hand. (Later on, when some of the plants got too big to pull by hand, they used a tool invented in South Africa for the purpose: the Tree Popper).
The team worked in blocks of 900 square metres - blocks which they marked for themselves and pegged out using 30x30 metre pre-cut lines - and rested after each plot was completed. Resting was necessary because most of the land at Featherbed is steeply sloped, and the team often had to climb considerable heights to get to their work.
When they got into the rhythm, though, the members of the team were usually able to finish each block in a reasonable period of time (varying depending on the degree of difficulty of the slope). But, on a particular day, our hort realised that they’d taken more than twice as long to cover less than a third of the usual area. So, curious, he marked out a square metre test plot, and personally pulled out and counted every one of the seedlings he found there.
There were 217 of them.
217 seedlings x 900 square metres = 195,300 future Rooikrans trees.
Fourteen people pulled 195,300 invasive Rooikrans seedlings out of one, steeply-sloping, 900-square-metre block of land in less than a single morning!
Now THAT’S rehabilitation for you!
Motivation
So how did the team stay motivated to keep going, to keep doing the same thing over and over again through those endless hours out there in the sun and the rain?
“Two or three days into the project, I asked them if they knew why we were doing this boring stuff,” said our hort. “They did not. So I explained that invasive alien plants threaten the biodiversity of the habitats they infest - which threatens the local ecology as much as it threatens local economies, especially in tourism destinations like Knysna. Aliens also deplete our water resources and increase fuel loads, which causes wildfires to become far more damaging and destructive than the regular, lower-temperature veld fires that form part of the fynbos’s natural cycle. Simply understanding why we were doing what we were doing, and knowing that the job was bigger than any one of us, made all the difference, and the team remained motivated for the rest of the period of our contract.” he said.
Stabilising the slopes: Mats and why we removed them
Our first concern on seeing the exposed soil after the fire was that slippage might happen. It’s easy to understand why: the soil at Featherbed looks and feels very much like loose beach sand, and without plants to bind it, we were worried that it might wash right down into the lagoon. So, on received advice, we covered the slopes that we thought were most vulnerable with roll-on mats made of biodegradable netting filled with poplar-wood shavings, and we pegged them down to hold them in place.
But when our hort-friend looked carefully at what was happening beneath those mats, he found that the germination rate for all seeds left in the soil after the fires (indigenous as well as invasives) was far lower under the mats than it was on the exposed slopes - which slowed down the entire rehabilitation project. The mats also trapped the heat of the sun, which raised soil temperatures considerably (seeds don’t like that). The leaves of seedlings that did manage to germinate beneath the mats quickly became yellowed and unhealthy (chlorotic, or starved of chlorophyll), which caused those plants to grow slowly. It was also evident that the soil actually (in most places) held itself in place quite effectively.
A decision was taken to remove the mats, and, in those few places where we still felt we needed to protect the slopes against erosion, replaced the mats with lines of 30-cm diameter ‘sausages’ made of the same materials. These sausages were pegged down along the contours at intervals of between two- and four metres. The soil above each line was. worked into shallow, almost horizontal basins (‘swales’ in the jargon) to trap and hold any water that might seep down from higher up.
New planting
Although we quickly learned that our policy of minimum intervention worked best, we did find it prudent to speed up coverage of the ground in various places where the soil had been disturbed by the construction of our new facilities.
We planted the swales above our ‘sausages,’ for example, and also planted the exposed ground along the cut lines of our roads. For this, we chose mainly two species for this effort. Firstly Bitou bush (Osteospermum moniliferum. The seedlings we harvested from the veld, and allowed to grow in our on-site nursery. Secondly, a succulent groundcover called Sour fig (Carpobrotus edulis), which we also collected in the veld. Sour fig cuttings do not need any special preparation. "Simply cut ‘em and stick ‘em in the ground, no irrigation required."
Biological control
It’s probably no exaggeration to say that South Africa is a world leader in the science of biological control of invasive alien plants - and biological control agents are certainly helping us at Featherbed, especially where the Rooikrans is concerned.
At around the turn of the millennium, the Biocontrol Research Programme of the University of Cape Town’s Plant Conservation Unit identified and released a gall midge (Dasineura dielsii) onto the invasive Rooikrans trees of the Western Cape. The midge lays its eggs in the Rooikrans flowers, and by feeding on the flowers, the larvae cause them to form galls rather than set seeds - which prevents reproduction. We were excited to find that a viable colony of these midges had survived the 2017 fires.
The Plant Conservation Unit’s Prof. John Hoffman and two of his research associates visited Featherbed in April 2018, and then again in April 2019. After examining more than forty samples from each of two different sites on the reserve on each visit, they reported a dramatic decline in the number of viable Rooikrans seeds in the soil.
Reasons for this include firstly predation, mostly by field mice and other small mammals that began to re-establish themselves at Featherbed within months of the fires, secondly the removal of the seedlings that had emerged from seeds that had been resting in the soil before, during, and after the fires, and finally the fact that the Rooikrans on the reserve had been prevented from forming new seeds during almost two decades before the fires - so the stock of seeds in the soil had become a finite resource.
As our hort still likes to say: “Hearing Prof. Hoffman tell us that we were basically on top of our Rooikrans problem was one of the most satisfying moments of my time at Featherbed.”
Into the future
Although our hort and his aliens team left us after about 18 months of intense work, we’re acutely aware that the environment at Featherbed will need ongoing vigilance - and we’ve committed ourselves to keeping up their work for the sake of all the generations to come.
Biochar Seedballs Project
You can help us with our rehabilitation project when next you visit Featherbed Nature Reserve. Please click here for more information.
Our catalogue of life at Featherbed
Please visit Featherbed on iNaturalist.com to see images and our latest observations of the plants, birds, insects, and other life forms at Featherbed.
Comments