Fynbos of South Africa

Introduction

Fynbos (an Afrikaans word for a “fine bush”) is a vegetation type comprising hard-leafed, evergreen and fire-prone shrubs and heaths. Fynbos shares similarities with the kwongan of southwestern Australia, the Californian chaparral, the Chilean matorral, and the Mediterranean maquis. All these types of vegetation occur at approximately the same distance from the equator (between 30° and 40° south or north of that line), and are either on the western edges of continents or influenced by prevailing winds from the west.

Fig. 1. Simplified map of biomes of South Africa
(Department of Environmental Affairs & Tourism, South Africa)

Location

Fynbos occurs in the Cape region, the far southwestern tip of the African continent, in a 100-200km wide belt stretching between the coastline and the Cape Mountain Ranges. The Cape Mountain Belt is crescent-shaped, with the flank of its northern horn facing west toward the Atlantic and the flank of its eastern horn facing south toward the Indian Ocean. In the north fynbos reaches as far as Olifants River near Vanrhynsdorp, Klawer and Vredendal. In the east it reaches west of Port Elizabeth (fig.1).

Abiotic features

The Cape Mountains are not particularly high. Mountain belts are generally 1000-2000 m in elevation. The area has a mild Mediterranean-type climate, with sunny and dry summers. Rainfall concentrates in the winter months and ranges between 300 mm and 750 mm annually, showing a great variation up to 3000 mm in southern mountainous areas to 200 mm on the leeward slopes of the interior ranges.

Most of the surface of the Cape region is covered by soils derived from pre-Carboniferous rock. A Devonian-Ordovican series of sedimentary strata, the Cape Fold Belt, consisting of alternating series of Quartzitic sandstones and fine-grained shales, lies above the Precambrian Malmesbury System, composed largely of shales. Differential weathering of the parent rocks yielded two fundamentally different soil types, coarse-grained sandy soils, poor in essential plant nutrients and richer clay soils. Mosaic effects of soils are intersected by rainfall variation, frequency of fires, and by elevation and aspect, giving a number of ecological niches available to plant life (Goldblatt, 1997).

A variety of abiotic conditions gives division into 9 regions in the lowlands (tab.1) and 4 in the mountains (tab.2).

Tab. 1. Subregion in lowland fynbos biome

Subregions	Location	Elevation	Geology	Rainfall
West Coast Forelands	Extends from the Cape Flats (south) to the Olifants River (north)	from sea level to 300 m	Several outcrops of Cape granite. Coastal areas -acid, aeolian sands, calcareous sands, with limestone underneath; inland - Malmesbury shales	Winter rainfall; north – about 200 mm annual south – about 500 mm annual
Warm Bokkeveld	Located between the mountains in the basin at Ceres.	500 m - 600 m	Underlying rocks are Cape shales	Winter rainfall: 300 - 500 mm annually
Elgin Basin	Located between the Hottentots Holland and Groenland mountain ranges	250 m - 350 m	Underlying rocks are Cape shales	Winter rainfall: 500 - 750 mm annually
Agulhas Plain	Located on the southwestern coastal lowlands from Danger Point (west) to the Gouritz River (east)		Sandplains and gravelly bottomlands in the west, and extensive limestones and calcareous dunes throughout	West: winter rains: about 600 mm annually East: rain evenly distributed throughout the year - less than 400 mm annually
Breede River Valley	Located between mountains surrounding Worcester.	250 m - 300 m	Alluvial deposits (principally gravels and sands) with Cape shales along the valley walls	Winter rainfall: 250 - 350 mm annually
South Coast Forelands	Located between Caledon (west) to Mossel Bay (east)	150 m - 400 m	Underlain predominantly by Cape shales with silcrete- and ferricrete-capped hills, residual Cretaceous deposits and low hills of Cape sandstone	West: winter rainfall: 300 - 500 mm Eastward it changes into non seasonal rains.
Little Karoo	Located between mountain ranges.	400 m - 1000 m	Shale-derived hills and plains	Non-seasonal rainfall: 250 - 400 mm annually
Langkloof	Located is located between mountain ranges.	600 m - 700 m	Underlying shale and sandstone	Non-seasonal rainfall: 400 - 650 mm annually
Southeastern Coast Forelands	Located between the Tsitisikamma region (west) and Port Elizabeth (east).	from sea level to 500 m; mainly between 100 and 200 m	Shale- and conglomerate-derived (Cretaceous) valleys and plains, extensive sandstone mountain footslopes, sandplains and calcareous coastal dunes	Non-seasonal rainfall: 400 - 650 mm annually

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Tab. 2. Subregion in mountainous fynbos biome

Subregions	Location	Elevation	Geology	Rainfall
Western Mountains	Extend for 375 km from the Cape Peninsula (south) to the Bokkeveld Mountains (north)	south to north: Cape Peninsula: 1086 m Hottentots Holland: 1590 m Hex River: 2249 m Groot Winterhoek: 1884 m Skurweberg: 2071 m Koue Bokkeveld: 1800 m Olifants River: 1015 m Cederberg: 2026 m Bokkeveld: 982 m	Series of sedimentary strata: some alternating quartzitic sandstones (Table Mountain and the Witteberg Groups) some alternating fine-grained shales (Bokkeveld Group) scattered outcrops of Precambrian granite, especially along the West Coast	Exclusively in the winter months, great variation: from 200 mm (along the Succulent Karoo ecoregion border in the northeast) to 3000 mm (on the upper slopes facing the coast in the south)
South Coastal Mountains	Extend from the Elgin Basin in the west, to near Port Elizabeth in the east, an unbroken chain of some 800 km	west to east: Groenland: 1201 m Riviersonderend: 1654 m Klein River: 964 m Langeberg: 1710 m Tsitsikamma: 1675 m Groot Winterhoek: 1758 m Elandsberg: 987 m		Extreme west: most rain falls in the winter months, elsewhere rain falls year-round. Annual rainfall: 800 - 1500 mm, along the inland foothills: less than 400 mm
Interior Mountains	North of the Little Karoo Basin, runs from Laingsburg (west) to the vicinity of Willowmore (east), a distance of 400 km	west to east: Witteberg: 1504 m Klein Swartberg: 2325 m Groot Swartberg: 2085 m Baviaanskloof: 1626 m		Annual rainfall :500 - 750 mm Interior foothills may receive 200 mm; upper slopes 1000 mm; extreme west: forms part of the winter-rainfall zone; extreme east: rainfall is bimodal with spring and autumn peaks, receiving rain throughout the year.
Little Karoo Inselbergs	Several isolated, fynbos-clad ranges within the Little Karoo, a basin between the South Coastal and Interior Mountains	west to east: Anysberg: 1622 m Rooiberg: 1490 m Gamkaberg: 1100 m Kamanassieberg: 1955 m Antoniesberg: 1720 m		Annual rainfall: 400 - 750 mm Northern foothills may receive as little as 200 mm; rain may fall at any time of the year, except in the extreme east where the distribution is bimodal

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Fynbos description

Fynbos is hard-leaved, evergreen, and fire-prone shrubland characterized by the presence of the following three elements:

1. A restioid component, belonging to the Restionaceae or the Cape Reed Family (fot.1). The Restionaceae, an old family that evolved in Gondwanaland, comprises approximately 480 species in the world, of which about 330 species inhabit the Cape region. These rush-like plants occupy the position of the grasses on nutrient-poor soils where there is a strong winter component to the annual rainfall.


Fot. 1. Restionaceae. Elegia filacea (Fot. A. Majchrowska, 2005)	Fot. 2. Erica sp. (Fot. E. Papińska, 2005)

The Restios are shallow-rooted with highly reduced dry, brownish leaves, and grow in clumps with the taller species being about waist high. The flowering spikelets at the ends of the stems typically give the landscape a greenish-brown look. Most of the species are dioecious. The male plants bears cones with pollen, while the female plants have cones with feathery stigmas to collect the pollen. Among the genera in this family represented in the Cape are Elegia, Ceratocaryum, Restio, Cannomois, Rhodocoma, Calopsis, Chondropetalum, and Thamnochortus. Fynbos is described as vegetation that has more than a 5% cover of Restios.

2. An ericoid or heath component (fot. 2) By far the majority of plant species - and the greatest cover after restioids - comprise plants with small, narrow, rolled leaves with thick-walled cells on the upper leaf surface and a channel containing hairs on the lower surface.

Fot.3 Senecio arenarius Hongerblom - Asteraceae (Fot. E. Papińska 2005)

Although the Heaths (Ericaceae) feature prominently, the Daisy (Asteraceae, fot. 3, 4), Blacktip (Bruniaceae), Pea (Fabaceae), Jujube (Rhamnaceae) and Thyme (Thymelaeaceae). Families also have structurally similar leaves.

The leaf characteristics are an adaptation to minimize water loss. About 80% of the Ericas are insect-pollinated, and the pollinators are often flies.

The great majority of species of genus Erica in the world are endemic to South Africa. It is speculated that the Ericas evolved after the break-up of Gondwanaland because they do not appear in either South America or Australia. Erica, with 657 species found, is the largest genus of flowering plant in South Africa. There are 625 species of Erica found in south-west Cape region, giving them the highest degree of regional speciation on earth (Rourke, 1996).

Fot.4. Daisies – Asteraceae (Fot. E. Papińska 2005)

3. A proteoid component (fot.5, 6). These plants, almost exclusively of the Proteaceae, have broad, isobilateral (both surfaces similar) leaves. They are the dominant overstorey in fynbos. Although some members occur in ecotones and some occur in renosterveld, by far the majority are confined to fynbos.

Fot. 5. Leucospermum cordifolium: Pincushion Proteaceae (Fot. E. Papińska 2005)

Proteas are generally shrubs with broad leaves and are mostly bird-pollinated. They are also characteristically deep-rooted, and they all have somewhat woody stems. What appears to be the protea flower is actually a flowering head made up of many long, slender flowers surrounded by a series of coloured bracts. Protea flowers do not have separate petals and sepals. Instead, they have what are sometimes referred to as tepals. The manner in which the tepals separate after the bud opens and the extent to which they remain fused at the base are characteristics which identify the various genera. The anthers do not have long filaments, but are attached near the top of the tepals, shedding their pollen onto the uppermost portion of the style just before the flower opens. Some species have four small nectaries situated at the base of the ovary which secrete nectar to attract pollinators. Proteas develop small dry fruits each containing a single seed. Some genera like Leucadendron have the sexes separated onto separate plants. Proteas’ two most important centres of distribution are South Africa and Australia. Africa is home to about 450 species of the Protaceae. These are currently classed into 14 genera, Protea (83 species), Leucadendron (82 species) and Leucospermum (49 species), being the largest (Paterson-Jones, 2000; Rourke, 1996).

Fot. 6. Leucadendron salicifolium; Common stream conebush (Fot. E. Papińska 2005)

Types of fynbos

Fynbos communities in different areas are not exactly the same depending on season, soil, slope, altitude and rainfall. However, although they may not contain precisely the same species, they are structurally very similar. In general, two basic types of fynbos, mountain and lowland fynbos, have been described. Lowland fynbos has perhaps more annuals and grass species, and is limited for the most part to sandy, clay or limestone soils. In addition to sandstone-derived soils, mountain fynbos may grow where rainfall is sufficiently high on leached soils derived from granites or even shales. Trees are relatively rare in mountain fynbos but some that do grow there are the Clanwilliam cedar, the silver tree, the wild olive and the mountain cypress. It is certainly to be suspected that the distinction between these two vegetative types is to some extent an artificial one. According to more detailed categorisation, fynbos has been divided into five separate vegetative types: mountain fynbos, grassy fynbos, laterite fynbos, limestone fynbos, and sand plain fynbos (tab. 3; fot. 7, 8).

Fot. 7. Mountain fynbos – Cape Peninsula (Fot. E. Papińska 2005)

Tab.3. Types of fynbos

Type name	Area and location	Abiotic features and key parameters	Vegetation	Conservation status
Mountain fynbos	27 462 km²; The most widespread vegetation type in the fynbos biome, occurring mainly along the Cape Fold Belt from north of Nieuwoudtville to Cape Town and Cape Agulhas and to near Port Elizabeth, with outliers in the Kamiesberg in the north. Altitude ranges from sea level to 2200 m.	Climate. Rainfall varies from 200 to over 2000 mm per year, occurring mainly in the winter months. Geology& Soil: Largely confined to soils derived from sandstones of the Cape Supergroup, except where the rainfall is sufficiently high, when it occurs on leached soils derived from granites (greater than 300 to 400 mm per year) and even shales (greater than 600 to 800 mm per year). Key Environmental Parameters: Summer drought has a major influence on vegetation and ecosystem processes. Not only do many species become dormant, but the vegetation is susceptible to fires which remove almost all above-ground fuel and burn off much of the available nutrients. The species are adapted to fires, which occur at cycles of between 6 and 45 years.	In terms of flora and structure, mountain fynbos has not been rigorously defined. Mountain fynbos is merely fynbos on the mountains of the fynbos biome.	±11% of the area transformed; 26,14% conserved. Much of mountain fynbos is conserved as water catchment areas. Woody alien plants are the major threat in this vegetation type: Pines Pinus spp., Needlebushes Hakea spp. and Wattles Acacia spp. are the most important, impacting not only on the flora, but also on tourism and water yields. Many localized, high-altitude species suggest that global warming may be a threat to some species. Certain pristine river systems are being considered for further dams.
Grassy fynbos	6 313 km²; The Eastern Cape from the Kouga Mountains to Port Elizabeth, and on the Grootrivierberge from Steytlerville to Grahamstown, and to Bushmans River Mouth, mainly on the mountain tops.	Climate: Grassy fynbos replaces mountain fynbos in areas where the component of summer rainfall increases. Geology & Soil: Mainly on sandy soils derived from Cape Supergroup sandstones, Witteberg Group quartzites and Enon conglomerates in the Uitenhage Group. The sandstones tend to be fine-grained in the east and thus yield slightly more fertile soils. Since this parallels the pattern of increased summer rainfall, it is difficult to untangle cause and effect. Key Environmental Parameters: Since the grasses result in finer fuel, fires are more frequent than in mountain fynbos.	The major difference between mountain and grassy fynbos is the high proportion of grassy elements in the latter, which tend to replace the restioid component. These grasses tend to be of the widely distributed genera: Brachiaria, Eragrostis, Heteropogon, Themeda and Trachypogon. In addition, the incidence of non-proteoid small-leaved shrubs and succulents (e.g. Aloe spp.) and hairy forbs separates grassy fynbos from mountain fynbos.	±3% of the area transformed; 16,14% conserved. Certain areas are very well protected. Representative examples are found in the Zuurberg National Park and the Baviaanskloof and Groendal Wilderness areas.
Laterite fynbos	616 km²; Occurs on the flats and lowlands of the Elim Flats in Western Cape, from 15 m to 100 m above sea level.	Climate: The climate is relatively uniform. Rainfall varies between 440 and 460 mm per year, mainly in winter. Average annual temperature ranges between 15°C and 16°C. Geology & Soil: The soil is derived from a variety of depositional material with gravelly, lateritic and seasonally waterlogged soils. Key Environmental Parameters: Unique features are the large expanses of seasonally waterlogged soils with surface water, surrounding the many pans and vleis in the area, and the lateritic soils.	An open to closed, low shrubland, with very occasional tall shrubs. The communities are species-rich and comprise a distinct centre of endemism. The area of the vegetation type is recognized as a major node of Red Data Book plant taxa, principally in the Proteaceae. Laterite fynbos is dominated by the endemic shrubs Elim Conebush, Roughleaf Conebush. and Bredasdorp Conebush. Blombos Metalasia muricata, Fine Featherbush, Elim Gonna and Disparago anomala are locally dominant species in the non-ericaceous ericoid guild, and many Heath Erica species are present. Compared to neighbouring vegetation types laterite fynbos is transitional between fynbos and renosterveld.	±50% of the area transformed; 0.47% conserved. There are no reserves or conservation sites in the area. Alien plants, especially Port Jackson Acacia saligna, are a major threat to existing stands. Many Red Data Book taxa are recorded from the area.
Limestone fynbos	2 148 km² In Western Cape from Walker Bay to Mossel Bay, on low, coastal, limestone deposits, from 0 to 290 m altitude.	Climate: The winter and autumn-spring rainfall area, with rainfall varying from 350 to 600 mm per year. Mean daily temperatures range from 12 to 22°C, averaging 17°C. Geology & Soil: Limestone fynbos is restricted to calcareous, neutral to alkaline, shallow sands overlying limestone and associated calcretes of the Bredasdorp Formation. Key Environmental Parameters: Limestone fynbos is confined to limestone and associated soils of the southern coast. On the coastal fringe, dune fynbos is dominant and is usually seral to dune thicket communities in areas which do not burn frequently.	Communities vary considerably in species composition between the shallow limestone soils and the deeper neutral sands. However, they are structurally very similar. The dominant species on limestone are: Limestone Sugarbush, Limestone Conebush, and Limestone Pincushion with Limestone Heath, and Whisk Reed. On neutral sands Stinkleaf Sugarbush, Mossel Bay Pincushion, Dune Conebush dominate, with Gonnabas, Ricebush, and the restioids, Muir's Reed, Jackaltail Reed, Broom Reed. Limestone fynbos comprises two centres of endemism with a transition zone in the Potberg area. Members of the Rutaceae may be abundant, especially on the ecotone with dune fynbos.	± 40% transformed; 13.84% conserved A large part of the De Hoop Nature Reserve comprises this vegetation type. Several private nature reserves occur in the region. The area contains the Bontebok NP. More conservation is required in the extreme west and east of the limestone fynbos, where elements not found at De Hoop occur. Huge stands of Rooikrans Acacia cyclops threaten this vegetation type.
Sand Plain fynbos	5 208 km²; From the Olifants River Mouth to Muizenberg on the West Coast lowlands from 5 to 300 m. In the lower Berg River region extensive mosaics of Strandveld succulent karoo and sand plain fynbos occur, apparently related to subtle physiographic changes in landscape which influence fire spread.	Climate: Mediterranean with summer drought. Rainfall from 200 to 500 mm per year, mainly in winter. Geology & Soil: This is confined to the deep acid sands of the West Coast. Most of these sands are of Tertiary origin, being aeolian and podsolized, but some are derived from the Cape Granite Suite and Table Mountain Group sandstones. In some areas waterlogging may occur. Key Environmental Parameters: sand plain fynbos is defined by the presence of deep, acid sands on the flats. It is confined to the West Coast, where the uniform conditions result in a relatively monotonous vegetation type.	The vegetation is typical Asteraceous and Proteoid fynbos and does not differ structurally from equivalent mountain fynbos types, although very few species are shared. Ericaceae are seldom dominant, but ericoid-leaved shrubs tend to dominate with Restionaceae and Proteaceae. Sand plain fynbos is characterised by the presence of Ninepin Heath, Baboonface, and the restioids Thamnochortus obtusus and Sandveld Thatching Reed. In the south the incidence of grass is much higher than in the north, but most of these are alien Mediterranean grasses. Three centres of endemism occur within this vegetation type.	± 50% transformed; 1.05% conserved. Only the Riverlands Nature Reserve and a few small Natural Heritage Sites currently conserve sand plain fynbos. The region comprises three major centres of endemism. Of these the southern-most centre is almost engulfed by the Cape (Town) Metropolitan Area. At least 84 Red Data Book Plant species occur in this vegetation type within the boundaries of the metropolis and are in danger of extinction. The vegetation is also heavily impacted by alien Acacia species. The area between Milnerton and Malmesbury must rank as one of the world's hottest spots for the loss of plant biodiversity.

Low, A.B. & Robelo, A.G. (eds) Vegetation of South Africa, Lesotho and Swaziland.
Department of Environmental Affairs and Tourism, Pretoria., 1996

Fot. 8. Fynbos in Agulhas Plain subrergion (Fot. A. Majchrowska , 2005)

Floral Kingdom and hotspot

Fynbos vegetation characterises the Cape floral kingdom, where it accounts for half of the surface area and 80% of the plant varieties. The Cape Floral Kingdom (CFK) or Cape Floral Region is the smallest of the six such natural areas in the world, and is the only one contained within the borders of a single country. The CFK comprises less than 0,04% of the earth's land surface, yet harbours 3% or 4% of the world's species. All of tropical Africa contains some 30000 plant species in almost 20 mln km². This high regional richness is a consequence of the extremely rapid changes of communities along geological, morphological and climatic gradients. Although geographically the Cape Floral Kingdom occupies less than 5% of the area of South Africa, more than 40% of all South African plants are to be found there. Owing to the remarkably high level of plant diversity and endemism, the region has been identified as one of the world's biodiversity hotspots. It is one of the five temperate Mediterranean-type systems on the hotspots list. In 2004 the Cape Floral Region was inscribed as the UNESCO World Natural Heritage site.

Unfortunately, biodiversity in the CFR is under threat from the spread of invasive alien species, land-use transformation due to agriculture and urbanisation, unsustainable harvesting and poor land-use planning.

References

Ecoregions of South Africa . www.routes.co.za/nature/ecoregions

Goldblatt P., 1997, Floristic diversity in the Cape Flora of South Africa. Biodiversity and Conservation 6, pp.359-377.

Low, A.B. & Robelo, A.G. (eds), 1996, Vegetation of South Africa, Lesotho and Swaziland. Department of Environmental Affairs and Tourism, Pretoria.

Paterson-Jones C., 2000, The Protea family in Southern Africa, Struik Publishers

Rourke J.P., 1996, Wild flowers of South Africa. National Botanical Institute, Kirstenbosch, Struik Publishers