Cape Elements on High-Altitude Corridors and Edaphic Islands: Historical Aspects and Preliminary Phytogeography

Abstract

The heathy, sclerophyllous vegetation type known locally in South Africa as 'fynbos' is not restricted to the Cape Floral Kingdom (CFK), but occurs throughout sub-Saharan Africa, Madagascar and the Mascarene Islands. The fynbos shrublands of these regions occur mostly in cool, montane environments where rainfall is high and soils are highly leached. Montane environments, however, are not the sole repositories of fynbos-type communities. Outcrops of Msikaba Formation (Pondoland) Sandstone in KwaZulu-Natal, South Africa, support similar shrublands, including many 'typical' fynbos genera and growth forms. The floristic and physiognomic resemblance of communities to the CFK, especially fragments of the high-altitude eastern (Afromontane) corridor extending into tropical East Africa, has prompted much speculation. A preliminary phytogeographical account is presented concerning the distribution of fynbos ('Cape') elements in the Drakensberg Alpine Region (DAR) and Pondoland Sandstone Region: two biotopes in southern Africa which share Cape elements. The significant sharing of Cape elements between biotopes suggests analogous growth environments.