The Cape floral kingdom or fynbos is the characteristic shrubland of the mountains and coastal lowlands of the southwestern and southern Cape of South Africa. It is of relatively minut extent and a large proportion of species in the fynbos flora have tiny ranges and exist in small populations. They are threatened principally by housing and development, pollution, agriculture, fragmentation, changed fire regimes, and the rampant spread of alien trees and shrubs.
The Cape floristic region, of which fynbos forms the dominant part, covers about 90,000 km2 (about the size of Portugal, or the state of Maine in the USA) and is home to more than 8500 species of higher plants and about 75 species of ferns and other non-flowering plants. The flora of this region is richer than that of any other area of equivalent size in the world. Almost three-quarters of the plant species in this region occur nowhere else on Earth. It is also a major repository for entire plant groups: for example it contains 526 of the world's 760 species of the family Ericacaea and 96 of 160 known species of the genus Gladiolus.
The name fynbos, which literally means 'fine bush', was coined by Dutch settlers, with reference to the dominance of fine-leaved shrubs in the vegetation, or specifically to its poor potential (being fine - 'fijn' in Dutch; 'fyn' in Afrikaans) as a forestry or fine wood resource.
Fynbos is best defined in terms of its unique mixture of three main plant types. Most conspicuous are the broad-and leathery-leaved shrubs of the Proteaceae family, many of them with the showy flowers for which the region is renowned. Heath-like shrubs, typically belonging to the Ericaceae family, with small leaves typically form the lower shrub layer. Thirdly, the single feature that most clearly distinguishes fynbos from other types of vegetation in southern Africa is the presence of Cape reeds: stout grass-like plants of the family Restionaceae. Besides the leucadendrons and proteas, ericas and Cape reeds, there are also many herbs with underground storage organs, such as bulbs, rhizomes and tubers, and annual plants such as daisies. Trees are usually confined to stream banks or sheltered ravines.
Fynbos ecology is distinguished by a Mediterranean type climate, with cool wet winters and hot dry summers. The summer droughts, together with the extremely poor soils that occur in most areas, and the intense fires that occur at intervals of between four and twenty years, have been the major driving forces in the evolution of the extraordinary assemblage of plants that comprise fynbos communities. Fire is a natural part of fynbos. It creates space and increases the availability of nutrients, light and water that otherwise limit regeneration in mature fynbos. The seeds of many fynbos species are stimulated to germinate by the chemical substances found in smoke or leached from healed or charred wood.
Fynbos is one of the world's richest repositories of biological diversity. It is not only the diversity of plants in the whole region that is special, but also the way that this floral richness is distributed within the region. The 60 square kilometres of Table Mountain alone supports 1,470 species.
It is estimated that 75% of South Africa's rare and threatened plants are found in the fynbos. The Cape Flats, an area under intense housing development, has the highest concentration of plant species in the Red Data Book. Overall 1,406 plant species are considered to be facing extinction.
The conservation status of fynbos is most critical on the lowlands, where only a very small part of the natural vegetation remains. Only about 5% of the total area of land in the fynbos that enjoys any formal conservation status is in the lowlands. Much more intact vegetation remains in the mountains which are not suitable for intensive agriculture and a large proportion of this land enjoys some form of protection. Invasive alien plants pose the greatest immediate danger to biodiversity in the fynbos. Thickets of Australian acacias and hakeas and forests of exotic pines cover thousands of hectares of fynbos. These stands suppress the native plants, destroy habitat for native animals and alter fire regimes.