Ecotonal Biomes of Southern Africa

This chapter presents continental ecotonal biomes (CEBs) that straddle zonobiomes E1, E2, S1, S2, T3, and A4. Zonobiome E2 (tropical seasonal zone) creates the largest (and ecologically most complex) zonoecotonal units—either when straddling the zonobiome T3 Warm-Temperate Zone (AMG African Montane Grassland units, including those representing the iconic Highveld) or S2 Hot Arid Zone (DHG Dry Highveld Grassland, incl. the arid grasslands marginal to Kalahari savanna). Endemic to South Africa is an intricate Albany Thicket, here interpreted as an ecotonal biome straddling zonobiomes S2 and E1 (subtropical section of the Equatorial Zone). Cape Valley Thicket (CVT) is found at the interface between S1 (Ethesial Zone), E1, and T3 zonobiomes. We hypothesise that this globally unique combination of bioclimates carries a relict signature. Several vegetation types found along the West Coast represent a transition between the zonobiomes S1 and S2 (WCS West Coast Arid Strandveld)—a bioclimatic situation repeated in all five global regions supporting the S1 Ethesial Zonobiome supporting the mediterranean-type ecosystems. The high elevations of the Cape Fold Mountains are home to a transitional CEB Cape Altimontane Fynbos, involving the S1 zonobiome and the austroalpine section of the A4 Antarctic Zone.