A pioneering alien vegetation clearing project at Vergelegen wine estate in Somerset West has revealed a natural treasure of indigenous vegetation.
Some 15 hectares of critically endangered Lourensford Alluvium Fynbos and 105 hectares of critically endangered Swartland Shale Renosterveld have been uncovered to date on the farm. The International Union for Conservation of Nature categorises this vegetation as facing an extremely high risk of extinction in the wild.
The Vergelegen project is believed to be the largest private conservation programme in South Africa. It was initiated by estate owners Anglo American after a wildfire about two decades ago, and should be completed by end-October this year. Only about 60 hectares of alien vegetation still need to be cleared, which will bring the total of restored vegetation to some 2200 hectares.
Lourensford Alluvium Fynbos
In the Western Cape, Lourensford Alluvium Fynbos originally extended over 6000 hectares, but only 9% remains. Some 3% of the original area is currently protected in the Helderberg and Harmony Flats nature reserves, with the remainder in the Lourens River area. Some 21 known Red Data plant species occur within this vegetation type.
According to a specialist botanical consultant, the Lourensford Alluvium fynbos on Vergelegen constitutes probably the only realistic chance to conserve a significant portion of this vegetation type. It consists of low-lying plains supporting low to medium dense shrubland with an underlying layer of short, grass-like herbaceous plants. Restios and asteraceous fynbos are dominant.
Swartland Shale Renosterveld
Swartland Shale Renosterveld originally extended over 495 000 hectares in the Western Cape, but only 8% of this remains. Less than 1% of the original area is currently protected. Some 151 known Red Data plant species occur within this vegetation type, with at least 35 endemic plant species.
This vegetation type consists of moderately undulating plains and valleys supporting low to moderately tall shrubland, with long slender leaves of varying canopy cover, as well as low, open shrubland dominated by renosterbos.
When this Vergelegen renosterveld area was surveyed previously, eight Red Data Book species and roughly 100 different plant species were identified. The renosterveld on the farm’s Schaapenberg area is a major regional conservation priority.
Vergelegen MD Don Tooth says the final stretch of alien vegetation to be cleared lies in high, difficult-to-reach terrain. The clearing team will have to tackle this in harsh winter weather conditions, but the end is in sight and it seems little will deter them. They will also undertake carefully controlled stack burns to dispose of large amounts of biomass from prior clearing, as these pose a fire hazard.
This huge project has created many opportunities for previously unemployed and unskilled people. All initial clearing is done by contract teams, with two teams of 35 and 40 people respectively employed. Workers are from local communities and they have been trained in skills such as chainsaw operation, herbicide application and first aid.
In addition to the jobs created for the initial clearing teams, three to four teams (of about ten people each) are employed to do annual follow-up work in the cleared areas.
“After clearing has taken place, it is extremely difficult to determine the size of the seed bank of invasive aliens,” says Mr Tooth. “Any wildfire will result in this dormant seedbank germinating, so it is vital that the maintenance programme deals with any re-emerging invasive aliens before seeds are produced.”
The project is also generating strong interest among researchers. Numerous scientific papers have been published in local and international journals and research findings are implemented into Vergelegen’s environmental management plan where applicable.
Currently, a Stellenbosch University scientist is working on a PhD based on the characterisation of wetlands by their biodiversity structures and processes; and another researcher from the same university is examining the advantages and disadvantages of drones in landscape ecology, for an ecology conservation degree.
The estate is also working closely with CapeNature, which would potentially re-introduce rare geometric tortoises into the area. The Lourensford Alluvium Fynbos vegetation is suitable for the tortoises, whose natural habitat is vulnerable to wildfires and other dangers.
“This has been a massive undertaking, made possible by dozens of people working as a team,” concludes Mr Tooth. “We’ve met visionary conservationists, fascinating scientists, and hard-working individuals from the local community who have created viable small enterprises through the clearing operations.
“Vergelegen estate was purchased as a national treasure for South Africa, and we are delighted that this privately funded project is revealing remarkable natural riches.”
Vergelegen conducts monthly bird counts, identifies wild flowers and (using infra-red camera systems) monitors wildlife movement. Species such as the Cape leopard, caracal, grey rhebok and spotted genet are regularly viewed on the footage.
On the estate the number of bird species has soared from 80 to at least 142 and at least 500 different plant species have been recorded.
