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PERDEBERG - home of zebras ... and tortoises
By Sue Winter, Biodiversity & Wine Initiative
During March 2006, Perdeberg Winery became the second co-operative cellar to achieve membership status with the Biodiversity & Wine Initiative. Nestled at the foot of the magnificent Paardeberg Mountain in the Swartland and named after the scores of Cape Mountain Zebra that once roamed this beautiful mountainside, the winery has 40 farms covering a total area of 16 500 ha of which 3 100 ha is planted to vines. The natural veld among the members totals 1 135 ha, which means that Perdeberg has 1 ha of conservation land for every 3 ha of vineyard!
Conservation has long been a priority amongst members of the Perdeberg Winery and conservation awareness has recently dramatically increased. Even the viticulturist, Stephan Joubert, now knows the difference between renosterveld and sand fynbos, and is on the look-out for interesting bulbs or tortoises during his visits to check on the vineyards! Evidence of Perdeberg's history of conservation involvement is the establishment of the Jan Briers-Louw Reserve in 1972 on a Perdeberg Winery member's farm that was proclaimed the first tortoise reserve in Africa. In fact, the whole of Perdeberg was proclaimed a Natural Heritage Site in 1992 by the Department of Environmental Affairs and Tourism due to its richness in botanical species and conservation importance. Furthermore, a number of landowners on the Perdeberg Mountain joined together to form the Perdeberg Conservancy, now chaired by Judy New from Slent farm.
What makes the Perdeberg and surrounding farms special is that it is covered by Boland Granite Fynbos on the mountain top (which is an endangered type of fynbos) and that there are still large fragments of critically endangered lowland vegetation on the foothills of the mountain, including the likes of Swartland Granite Renosterveld, Swartland Silcrete Renosterveld and Atlantis Sand Fynbos. While the Cape Mountain Zebras have sadly disappeared on the mountain, many rare and endangered plant species can still be found. For example on the farm Vlakfontein, owned by SP Van Blerk, a 115 ha patch of undisturbed Atlantis Sand Fynbos is located, which is an excellent representation of what the landscape would have been like before agricultural development. 14 Red Data List species were recorded when it was last surveyed, and a major part of the site is dominated by the endangered sandveld pincushion (Leucospermum parile) and the vulnerable silver-paw spiderhead (Serruria incrassate) was found at the site.
Several farmers have made great efforts to conserve their remaining natural areas and clear alien infestations. Mike Orpen of the farm Blijdschap, for example, has already felled 2 300 blue gum trees since the beginning of March 2005. Blijdschap also has a 40 ha site that contains a rich composition of bolplantjies associated with the granite rocks at the site. The site was an old orchard that is currently being rehabilitated by Mike who is devoted to conserving his land. There is an 18 ha remnant patch of Swartland Granite Renosterveld on the border between the farms Papkuilsfontein and Moerasfontein near Malmesbury, owned by the Geldenhuys brothers. The site follows a ridge formed by a series of rock outcrops, which has pristine veld and a number of interesting succulent species associated with the granite rocks.
The farm De Kopje owned by Lize & Hennie Mentz, includes about 700 ha of Boland Granite Fynbos on Perdeberg Mountain itself and is one of the largest pieces of pristine, privately owned habitat on the mountain. It has recently been the subject of a detailed botanical survey where a number of Red Data List species were also identified on this valuable piece of land. The farm Hoogstede, also part of Perdeberg Winery and situated on the western side of Paarl Mountain, contains 110 ha of unspoilt natural vegetation representing a mixture of Boland Granite Fynbos and Swartland Renosterveld types where numerous Red Data List (RDL) species have been recorded. The owners/trustees of Hoogstede recently committed themselves to never developing the natural area on the property. A worthy commitment indeed!
With such significant conservation highlights, Perdeberg Winery is setting a great example for other co-operative cellars of what can be done to conserve the rich biodiversity that often occurs on our back doorstep. I wonder who will be the next co-operative cellar member of the Biodiversity & Wine Initiative?
For more information about Perdeberg, contact Stephan Joubert at tel: (021) 869-824,e-mail: stephan@perdeberg.co.za or visit www.perdeberg.co.za.
The Cape boasts an impressive level of tortoise diversity. South Africa itself has the highest tortoise diversity on Earth, and five species are found almost exclusively within the Cape Floristic Region. These include the angulate tortoise, parrot-beaked tortoise; leopard tortoise and geometric tortoise. The geometric tortoise (Psammobates geometricus) is one of the rarest tortoise species in world, but also one of the most beautiful in the world characterised by bright yellow geometric patters on a black carapace. Geometric tortoises are the only ones of South Africa's twelve land tortoises which may face extinction. Although all tortoise species of South Africa are protected by law, this does not automatically stop them from the threats of their disappearing habitats.
The rarest of them all
The distribution range of the geometric tortoise, commonly known as the 'suurpootjie' is restricted to the areas where West Coast renosterveld used to occur, which is also unfortunately the preferred habitat for the wheat and wine farmer. The largest single population consisting of approximately 2 500 individuals is found on a private nature reserve near Wolseley, containing about 1 000 ha of suitable tortoise habitat. The current estimated population size is approximately no more than 5 000 tortoises. However current data is lacking as to the exact locations and numbers of all remaining tortoises that still survive on small renosterveld fragments on private land, and therefore the co-operation of farmers is desperately needed. The greatest threat to the geometric tortoise is man's alteration and destruction of its natural habitat, including threats such as too frequent fires, the spread of alien vegetation, crop-spraying, interference with drainage lines, and over-utilisation of veld by stock. Residues of a variety of chemicals used as pesticides and fertilizers in surrounding wheat-fields and vineyards can find their way into the remaining tortoise habitats. Geometric tortoises cannot tolerate changes to their natural habitat and they do not survive where renosterveld has been destroyed or mis-managed. Therefore the fate of this beautiful and endangered tortoise rests entirely with landowners who at any time could plough the land or destroy their habitat in other ways.
What do suurpootjies eat and what habitat do they prefer?
The fact that geometric tortoises are confined to West Coast renosterveld indicates that their diet must be very specialised. In winter, they mainly eat bulbs, annual grasses and other herbaceous plants, while perennial grasses, shrubs and succulent components are important food resources during dry summers. Geometric tortoises prefer low-lying, relatively open renosterveld areas of medium height (50 - 100 cm) within the 350 - 600 mm winter rainfall areas. Four main factors, namely food, cover, nesting and the ability to move around in the habitat are important for the survival of these special tortoises.
On the farm Eensaamheid, which delivers grapes to Perdeberg Winery, the JN Briers-Louw Tortoise Reserve was established in 1972 as the first tortoise reserve in Africa. It was proclaimed a Provincial Nature Reserve when a population of geometric tortoises was found - this after the initial perception that this species were extinct or almost extinct. The reserve was specifically proclaimed for the Geometric tortoise population as well as many important threatened and Red Data plant species found on the reserve.
References:
The Southern African Tortoise Book, p. 145-149.
Baard, E., 1995. A preliminary analysis of the habitat of the geometric tortoise, Psammobates geometricus. S. Afr. Journal of Wildlife Research 25(1): 8-13.
http://www.biodiversityhotspots.org
If so, you have a biodiversity gem well worth conserving! And what a great biodiversity story they can create to go with your wine! Because these species are threatened with extinction, take care in who you tell this information to, and the general access to the area where they are found. Please contact CapeNature (Ernst Baard) if you have geometric tortoises so that a database can be created of privately owned renosterveld fragments that still contain these rare tortoises.
For more information, contact Ernst Baard, head of Scientific Services at CapeNature. E-mail: baarde@cncjnk.wcape.gov.za, tel: (021) 866-8000.
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