Saturday, February 28, 2009

Is Our Mountain Drying Out?

- Reinwald Dedekind and Judy Maguire -

Whether you approach the Swartberg Pass from the Prince Albert side or from Oudtshoorn, coming across the tall pine forests on the Pass was always a welcome sight, with the stately ‘heritage green’ pines standing in stark contrast to the olives and greys of the surrounding fynbos. They offered the only decent shade and shelter from the wind to be had, except for a few shaded cutbacks in kloofs on the south side, where it is not possible to leave the road and enjoy. The forests of the Swartberg Pass, or plantations rather, were picnic venues of note, with carpets of deep soft pine needles, fragrant with pine resin and suffused with that unique swishing sound of the wind through the needles. The views from all three plantations were superb. Our particular favourite was the forest just after the turn-off to Gamkaskloof, close to the beginning of the Otto du Plessis Road to Gamkaskloof, where a particularly large pine specimen had half blown over, exposing its thick gnarled roots which made a comfortable bench.

Visitors to the town, and even some locals, are still asking why the forests had to be axed, even though they have been a thing of the past for well over a year now. This is their story.

When settlers arrived at the Cape from Europe, there were substantial indigenous Afromontane forests such as the ‘Kirstenbosch’ forest and others, mainly on the eastern side of Table Mountain, but also in the aptly named Hout Bay on the Atlantic side. Afromontane forest is very widespread in Africa, occurring in mountainous areas as far north as Ethiopia, in deep sheltered kloofs where they are protected from fire. There are many species in common.

Timber was needed for the many building projects embarked upon by the Dutch East India Company: for the first fort, for defensive palisades and stock kraals, for houses and shelters, to repair the wooden ships of the day, for wagon making, bridge-building and the like. Firewood was a daily necessity for domestic use and wood was needed in vast quantities for passing ships, to fire the lime kilns and later brick kilns, and to extract oil from seals and later whales at Dassen Island and Saldanha Bay. This huge demand seriously depleted the indigenous forests closest to the Cape within 70 years. From 1725 onwards, the forests of Riviersonderend, the Grootvadersbosch near Swellendam, the Outeniqua forests and even further afield at George and Plettenberg Bay were being exploited for their timber. Contracts were awarded to licensed woodcutters and no exploitation of the forests by private individuals was allowed. But still the insatiable demand for wood continued to grow.

The discovery of diamonds and then gold created a huge demand from the mining industry. Wood was needed for mine props and a host of other mining related activities. It became clear to the National Forestry Department of the day that South Africa needed an afforestation programme: indigenous trees are notoriously slow growing and for this reason, a variety of fast-growing imported or alien species were tried. In this area of the southern Cape and on the Swartberg in particular, pine species were imported (in the form of seed) from several countries which, like the Cape, have a Mediterranean-type of climate. Conifers were imported from California, Mexico, Italy, Corsica, Portugal, southern France, and even from northern India which does not have a Mediterranean climate. The Swartberg was chosen for suitability tests to ascertain which of the species would do best in the nutrient deficient, sandy and very acid soils of the quartzitic mountain ranges. The forests of the Swartberg were in fact experimental forest patches.

In the late twenties and early thirties, young pine trees were propagated in nurseries for later planting on the Swartberg. This was done in four plots at different altitudes: the south forest at a lower altitude, about a third of the way up the mountain, the main forest opposite Die Ou Tol, just below Die Top, the Scholtzkloof catchment forest at the start of the Otto Du Plessis road, and the last, close to Klippiesvlei, where there was a forestry outpost, formerly manned by the Wicomb family. Even cork oaks (to supply the burgeoning local wine industry) were tried, two specimens of which remain, their thick corky barks protecting them from the depredations of fire.

At that time, fires were controlled and firebreaks were constructed and maintained and different portions of the mountain were burned on a systematic basis. Firebreaks around each catchment enabled control so that it was unlikely that more than a few catchments would burn in any one uncontrolled fire. In the late 1980s this management passed from the Forestry Department to the then Cape Nature Conservation Department which abandoned controlled burning and started an open system whereby the mountain burns ‘naturally’ – i.e. by lightning-induced fire. In time, much damage was done to the trees, not only by devastating fires but by strong winds uprooting some and breaking side branches. Mature pine trees do not easily re-generate. However, their wind-blown seed was blown out into the surrounding fynbos and in time, an incipient ‘alien invader’ problem developed. An invader is any species which can establish more than 100 metres away from the parent clump.

Even prior to the declaration of the Swartberg as a World Heritage Site (it is one of the eight elements of the “Cape Floral Kingdom” World Heritage Site), CapeNature had decided to eradicate all the existing pine trees. Eradication of alien invasive species is seen as a necessary part of management, because ongoing invasion clearance is time-consuming and expensive. The trees were doomed. The issue was brought to a head when the remaining three forests succumbed to devastating fires around Easter-time, 2007. The trees had to be felled before the wood deteriorated any further and became unsaleable. The forests were axed within a few weeks. The Klippiesvlei forest had burnt down and been felled several years prior to this.

Even had the experiment proved successful and had forests been established, fire would have been an ongoing problem. The recent fires on the mountain attest to the frequency with which they can be started by dry electric storms – lightning strikes, in other words. Today many fires are started by humans rather than lightning. Fire is an essential ingredient of fynbos ecology. Fynbos needs a good burn every 10 to 14 years or so, otherwise a thick canopy of dry and dead material accumulates under bushes and shrubs. However, overburning can also do permanent damage by not giving certain species a chance to grow to maturity and set seed, before another fire burns them off. In this way, seed bank depletion can occur. Proteas usually survive because ants pick up their seeds and carry them underground into their nests where they germinate after having been smoke-stimulated.

The branches of fynbos plants contain a lot of tannin making them highly combustible, enabling the slightest spark to set them alight. After a fire, the ‘siergrasse’ or restios are usually the first to appear, after the geophytes such as the Watsonias, whose underground bulb makes them fire-resistant. The seeds buried by the ants take some time to germinate, and protea trees take many years to reach a good size. Older residents recall the Protea Forest at the turnoff to the Otto Du Plessis road, and for many kilometres along it, with “trees big enough to climb in, as a child”. The Protea Forest, like the pine forests, is alas no more, and so are the heavy snow falls of yesteryear which used to keep the pass closed for several days or even a fortnight at a stretch.

Is our mountain drying out?

Additional information supplied by Hannes Scriba, the Wilderness.

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