Partnerships in the DCCP: Conserving the Critically Endangered Oxalis Natans

July 19, 2021

For over 100 years, the Nieuwepost Farm has been a multi-generational family farm, in the West Coast District Municipality, not too far from Darling. Vlakenberg Farming, a mixed agricultural business, farms various types of livestock and winter small grains, which produces various olive products on Nieuwepost, whilst roughly a third of the farm is used for livestock grazing. The land contains large tracks of Renosterveld and Sand Fynbos vegetation, which is located within the Dassenberg Coastal Catchment Partnership (DCCP).

The olive plantation of Vlakenberg Farm.(Image sourced from https://vlakenberg.co.za/about-us/)

The DCCP is located in the Cape Floral Region, the smallest of the six floral kingdoms in the world, with the highest concentration of plant species in one area. The DCCP aims to protect biodiversity while positively impacting the livelihoods of the communities located in this area. The GEF-5 PA Project, through CapeNature as an implementation partner, has supported the DCCP by funding the DCCP coordinator’s post. This has helped to maintain and further establish partnerships with other conservation agencies and relevant government departments.

In September 2019, Jacques van der Merwe from the City of Cape Town’s Biodiversity Management Branch, came across a large population of Oxalis natans, also known as Waterklawer in English, in a 2-hectare vernal pool on the farm. This is an enormous westerly range extension for the species. At present the species is restricted to only two small populations, Elandsberg Nature Reserve, and a small roadside reserve close to the Jonkershoek Nature Reserve, near Stellenbosch. Oxalis natans is listed as critically endangered on the Red List of South African Plants. It is very sensitive to eutrophication and changes to hydrological flow. The vernal pool is in one of the winter grazing camps on the Nieuwepost Farm and as such is at risk of trampling and eutrophication.

The critically endangered Oxalis natans, also known as Waterklawer. Image: Jacques van der Merwe.

Apart from the incredibly rare Oxalis natans, the wetland around the pool is home to a host of other threatened species, including Geissorhiza eurystigma (endangered), Ixia curta (endangered) and Aponogeton angustifolia (near threatened). Vernal pools are also breeding and feeding habitats for a range of water birds including Blue cranes (vulnerable), Black harrier (near threatened), Yellow-billed ducks, Greater flamingo, Black-winged stilts, various plovers and kingfishers. These natural pools on the Nieuwepost Farm also have healthy amphibian populations including Cape sand toad, African clawed frog, clicking stream frog and Klipheuwel caco.
As a result, Vlakenberg Farm decided to put up a fence to protect this highly sensitive environment. This would ensure that all species could benefit from the reduced grazing pressure and improved habitat quality. Funding from the Table Mountain Fund (TMF) was used for the procurement of fencing material for the site.

One of the farm workers erecting the fence. Image: Jacques van der Merwe.

In December 2020, the Nieuwepost Farm was purchased by Peter Duckitt, the owner of the neighbouring Cloof Wine Estate, a WWF Conservation Champion. When the new landowner was made aware of the conservation project underway, he suggested expanding the area. Duckitt agreed to sign a voluntary conservation stewardship agreement upon transfer of the property, over the high quality renosterveld wetlands around the vernal pool. This increased the size of the fenced off area from 2 hectares to 6.3 hectares.

Completed fenced off area. Image: Jacques van der Merwe.

The additional 4 hectares of critically endangered Swartland Granite Renosterveld wetland meant that an extra 400m of fencing was required. The Western Cape Department of Agriculture through their LandCare programme supported the initiative and donated fencing material. The landowner covered the costs of the Cape Vernal Pool information board. The fencing was done by highly qualified farm workers and was completed at the end of April 2021 – just in time for the winter rains to fill the vernal pools without any harm from grazing.

The Cape Vernal Pools information board funded by the farm owner. Image: Jacques van der Merwe.