Namaqualand Sand FynbosNamaqualand Sand Fynbos was not formally recognised as a Fynbos vegetation type until the publication of South Africa’s National Vegetation Map in 2006. Previous national vegetation mapping by Acocks and by Low and Rebelo, published in 1953 and 1996 respectively, classified this large, remote area as a form of Succulent Karoo with no mention of the striking Fynbos elements present on the Namaqualand coastal plain.

 

This is a Sand Fynbos habitat that is classified as part of the Fynbos Biome rather than as part of the surrounding Succulent Karoo Biome, which is represented by Strandveld vegetation units. Namaqualand Sand Fynbos is the driest of all Fynbos types, with average rainfall ranging from 75 to 150 mm. This west coast vegetation type is supplemented by dew and fog as sources of moisture. The presence of large, fog-trapping, Sand Fynbos-filled depressions in the coastal plain, such as Die Kom near Brand se Baai, suggests that these fog bowls have acted as refuge habitats for Sand Fynbos in the face of historic climate change.

Namaqualand Sand Fynbos spans around 240 km from the Olifants River, west of Koekenaap, near to Koingnaas, west of Springbok. Mapping by Dr. Philip Desmet and Nick Helme suggest that the total area of this vegetation type is about 110,000 ha. It can be difficult to define an exact boundary between Namaqualand Strandveld and Namaqualand Sand Fynbos, as the ecotone (habitat transition) can be gradual and diffuse. This is also the only locality in the world where Fynbos and Kalahari habitats co-occur and where Camel Thorn trees (Vachellia erioloba) naturally co-exist with Pincushions and Cape Reeds.

Namaqualand Sand Fynbos is a relatively species-rich vegetation type with over 550 species recorded versus 486 in adjacent Strandveld. This Fynbos system seldom burns and is described as having an extremely low natural fire-frequency. Fire is not needed for germination or recruitment in this vegetation type and youngsters merely come up in available gaps, some of which are left by the death of elder plants.

Genera typically found in southern forms of Sand Fynbos, such as Erica, Staberoha, Protea and Serruria are absent from Namaqualand Sand Fynbos. Some of the dominant species in the southern vegetation types are present but in low numbers. Exciting discoveries made in this vegetation type in the last decade include at least four new species, plus the documented occurrence of numerous species that were not known to occur much north of the Olifants River.

There is a lot more to discover. Relative to the Sand Fynbos vegetation types south of the Olifants River, Namaqualand Sand Fynbos is poor in endemic species, and, with a few exceptions, the Fynbos elements tends to be less common. Babiana teretifolia and Romulea lutea were discovered in 2007, and are presently known only from the southern tip of this vegetation type, just west of Koekenaap. Elegia namaquense and lachenalia arenicola are other recent discoveries, the former (still in press) being known from a few patches between Lotzesrus and the Spoeg River, and the latter occurring throughout the full range of the vegetation type.  These recently discovered species all appear to be endemic to this vegetation type and, given the imminent threats to this habitat, will all be Red Listed as threatened.

Lampranthus procumbens also appears to be a habitat endemic, but is a northern species, extending from Kommagas south to Kotzesrus. A legume, Calobota lotononoides, is shared with Strandveld, but was also described only in 2007, and is now known from the full extent of this vegetation type.

The sands supporting Namaqualand Sand Fynbos are notably less alkaline than the sands which support the many forms of the adjacent Namaqualand Strandveld, though they are not as acid as the soils in typical Fynbos further south. The sands also seem to be rich in heavy minerals, notably zircon, rutile, titanium and ilmenite.

The primary land-use in this vegetation unit is low-intensity grazing by livestock. Grazing and browsing pressures are usually moderate, with low densities of antelope and livestock. Approximately 4,000 ha have been cultivated for cereals and supplementary grazing.  The primary long-term threat to this vegetation type is mineral sand mining. Heavy minerals in these sands are components of a variety of industrial products, most notably ceramics, cosmetic, pharmaceuticals and paint.

Namakwa Sands was the first commercial operation at Brand se Baai and has recently received authorisation to strip-mine a further 5,000 ha in addition to the approximately 7,000 ha already mined. About a third of this area is in what is, or was, Namaqualand Sand Fynbos. Prospecting rights to some 30,000 ha have been granted to Exxaro and various other companies reaching as far north as Bitter River. Within two decades one may well be looking at the potential loss or degradation of close to 50% of the total historical extent of the Namaqualand Sand Fynbos.

The mining operations do attempt rehabilitation, however, the mining process mixes the soil profile and what is returned to the landscape is an ‘average’ of what was there previously. While mineral sand mining restoration efforts can successfully rehabilitate Strandveld communities, this is not so in Sand Fynbos, and much of the diversity and complexity is likely to be lost forever. Mining is also having landscape-level impacts on ecological processes.

Unfortunately given the remoteness of this region very few people are aware of this growing threat. Fortunately around 11,000 ha are now protected within the Namaqua National Park, but it is recommended that the proportion conserved be expanded soon. A number of adjacent properties have been recommended as biodiversity offsets for the proposed Zirco Groen River mineral sand mine, however, the southern parts of the Namaqualand Sand Fynbos, far from Namaqua National Park, remain vulnerable.

Through the efforts of the South African National Parks, the Leslie Hill Succulent Karoo Trust and also through effective implementation of biodiversity offsets for mining and renewable energy projects, it is possible that we could see large tracts of this special Namaqualand vegetation type protected for future generations.

Article adapted from Veld & Flora, June 2015 by Nick Helme and Dr. Philip Desmet

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