There are 34 internationally recognised biodiversity Hotspots in the world. One of them is the Cape Floral Kingdom, the smallest of the six Floral Kingdoms of the world and the only Kingdom encompassed entirely within a single country. The Cape Floral Kingdom is divided in five different vegetation types or biomes, two of these are found in the Cederberg Conservancy namely the Fynbos Biome and the Succulent Karoo Biome. The Fynbos biome is subdivided in two distinct vegetation groups, Fynbos and Renosterveld.
The vegetation of the conservancy area changes from Fynbos to Succulent Karoo as the climate and geology change from west to east, with Central Mountain Renosterveld to be found in the transition area. The Cederberg Wilderness and adjacent farms comprise of Fynbos vegetation, while vegetation in the eastern section of the Matjiesrivier Nature Reserve and adjacent farms to the east and south changes to Central Mountain Renosterveld and Succulent Karoo.
The Fynbos Biome is largely within the boundaries of the Western Cape with an estimated 9 500 species of which 70% are endemic and contained in this biome. Only 9% of this biome is formally protected.
Fynbos vegetation is largely confined to soils derived from sandstone which are well-leached, infertile soils. Fynbos is recognized by the presence of reeds (Restionaceae), ericas (Ericaceae) and many different types of Proteaceae such as sugarbush proteas, cone bushes, pincushions and spiderheads. Plants commonly seen at lower altitudes are the grey-leaved sugarbush (or suikerkan; Protea laurifolia), the spinning top (or tolletjiebos; Leucadendron rubrum), and the common sunshine conebush (or stompieknopbos; Leucadendron salignum). Waboom veld is a predominant feature of the lower slopes where the sturdy, fire-resistant wagon tree (or waboom; Protea nitida) gives an almost savannah-like appearance to the landscape. In spring bright patches of purple-blue ridderspoor (Brachy-capaea juncea) are eye-catching, as are the large yellow Clanwilliam daisies (harpuibos; Euryops speciossimus, and Sederberg-harpuis; E. wageneri).
The Cederberg Fynbos is also home to the rooibos tea plant (Aspalathus linearis) and many different types of buchu (Rutaceae) with their fragrant oils. Wild olive trees (Olea europaea subsp. africana), rockwood (or kliphout; Heeria argentea), and rock candlewood (or klipkershout; Maytenus oleoides) form woody thickets on dry slopes and round rocky outcrops. In contrast, plants growing along stream banks include the wild almond (or wilde-amandel; Brabejum stellatifolium), the lance-leaved myrtle (or smalbaar; Metrosideros angustifolia), and in the streambed itself grows the palmiet rush (Prionium serratum). On the high plateaus red disas (Disa uniflora) and other orchids occur close to water. The endemic snow protea (or sneeuprotea; Protea cryophila) occurs on the snow-line of some of the high peaks only. The Clanwilliam cedar tree (or sederboom; Widdringtonia cedarbergensis) after which the Cederberg is named, grows along cliffs and rocky areas at an altitude of between 1 200 and 1 700 m.a.s.l. and occurs in a patchy distribution over about 250km2 in the Cederberg. This handsome tree with its gnarled growth form has fragrant, durable wood - a feature shared with the true cedars, such as the Lebanon cedar (Cedrus libani). The endemic Clanwilliam cedar which was formerly more numerous is now threatened with survival due to several centuries of exploitative harvesting and frequent fires. A unique feature of the dry, eastern Fynbos areas is the presence of large, flat, rock platforms. Plants such as the Clanwilliam sugarbush (or kreupelwaboom; Protea glabra) and many different kinds of small, succulents grow in cracks in the rock slabs. Fynbos vegetation is fire-prone and fires are often a feature in the dry summer season. Fynbos has evolved over millions of years and Fynbos plants have a wide spectrum of survival strategies. However, fires that are too frequent pose a threat to many Fynbos species.
The changeover from Fynbos to succulent Karoo occurs in the valley along which the Wupperthal – Ceres road passes. It is in this transition that Central Mountain Renosterveld is located on the fine-grained clay and silt soils, derived from shale which is more fertile than the sandstone soils. In places the components of both Fynbos and Succulent Karoo plants can be seen, reflecting the transition between the two vegetation types. Renosterveld is characterised by the dominance of members of the daisy family (Asteraceae), particularly renosterbos (Elytropappus rhinocerotis) from which the vegetation gets its name. This vegetation type is also rich in geophytes of the iris- (Iridaceae), lily- (Asphodelaceae, Colchicaceae, Hyacinthaceae and Eriospermaceae) and orchid families. Grasses are also abundant if not overgrazed by livestock.
The Succulent Karoo Biome is shared with Namibia and the Northern Cape and unlike other arid areas this biome has exceptional high biodiversity. This biome has about 4 849 recorded plant of which 1 940 are endemic. Only 1% of this biome is formally protected.
The occurrence of the Succulent Karoo is primarily determined by low winter rainfall (20 – 290 mm per annum) and extreme summer aridity. The Succulent Karoo vegetation is characterised by the abundant presence of "vygie" (Mesembryanthemaceae) and Crassulacaea families. The "daisy" family (Asteraceae) is also well represented. Although the vegetation here is sparser than the relatively "lush" Fynbos vegetation to the west, the succulent Karoo produces bright displays of spring-flowering vygies, daisies and other annual flowering plants after a good preceding rain season. Some of the large succulent-stemmed plants characteristic of the area is the gifmelkbos (Euphorbia mauritanica) and the botterboom (Tylecodon paniculatus). There are also many species of small, succulent-leaved Mesembryanthemaceae. Interesting plants that are not readily seen, but are worth hunting for are the elephant's foot (or olifantsvoet; Dioscorea elephantipes), and a type of gifbol (Boophane haemanthoides). The Namaqua fig (or Namakwavy; Ficus cordata) is a tree that grows flattened against rock faces in the area. A feature of the area is the regular pattern of large, round "heuweltjies" or mima-like earth mounds (0,1 - 0,5m high and 2 - 10m in diameter) supporting "islands" of vegetation that are noticeably different from the surrounding vegetation. These are old termite mounds where the soil has been altered by termite activity and hence support certain plants such as the daisy, Pteronia divaricata, and Tylecodon paniculatus. The Succulent Karoo hardly, if ever, burns.
Interesting books for further information on the vegetation and plants
Taylor, H.C. 1966. Cederberg Vegetation and Flora. Strelitzia 3: 1-75. Van Rooyen, G. & Steyn, H. 1999.
Cederberg: Clanwilliam and Biedouw Valley: South African Wild Flower Guide 10. Botanical Society of South Africa, Kirstenbosch