Vegetation type endemic to the city of Cape Town, South Africa
Peninsula Granite Fynbos is an
endangeredFynbos vegetation type which is endemic to the city of
Cape Town and occurs nowhere else. It is a unique type of tall, dense and diverse scrubland, scattered with
trees. It can be found all along the belt of
granite that encircles
Table Mountain.[1][2]
Natural Distribution
This unique vegetation type occurs only within the city of
Cape Town, particularly in a band that encircles the
Table Mountain range – following the stratum of the Cape Granite Suite. It occurs from
Lion's Head in the north, to
Hout Bay and
Muizenberg in the south. There is also an isolated patch near
Simonstown, further to the south.[3]
It grows on the gentler, lower slopes of Table Mountain, over rolling hills and valleys - in rich, deep soils formed from eroded granite. Because of the rich soils and gentle terrain, most of this ecosystem has been destroyed to make way for vineyards, wealthy
suburbs and commercial
pine plantations. In fact, the largest patches of exposed granite soils are at
Newlands,
Wynberg Hill and
Constantia, and these are all areas that have been developed for housing, farmed, or planted with invasive
pine trees.
Description
Peninsula Granite Fynbos is dominated by
Asteraceous (
daisy) and
Proteoid (
protea) species, although
Erica and
restio species become more dominant in wetter patches.
There are two distinct subtypes of this vegetation: the especially endangered South Peninsula Granite Fynbos which grows on the more lush southern and eastern slopes, and North Peninsula Granite Fynbos which dominates the drier northern and western slopes.
A striking feature of this vegetation is the presence of massive, tree-like
Proteas such as the groves of
Waboom trees (Protea nitida) which grow in the northern section, the famous
Silvertrees (Leucadendron argenteum) which dominate the wetter southern and eastern slopes, and the endemic
Grey Tree Pincushion Protea (Leucospermum conocarpodendron) which covers the drier western slopes. Tall, dense, indigenous
Afromontane Forest (a very different vegetation type) takes over from fynbos in any areas that are protected from seasonal fires, especially in river valleys and wetter areas.
Peninsula Granite Fynbos used to support a great many wild animals but the larger game is now mostly locally extinct.
Threats and Vulnerable Species
Today the major threat to this endangered ecosystem is definitely from invasive alien plants. The two main invaders are
Wattles (especially Blackwood, but also
Black Wattle and Stinkbean) and
Pines. In fact, much of the remnants of this endangered vegetation type are still beneath large commercial
pine plantations. However, apart from the main two, there are a great many other invasive plant species – both trees and smaller plants. This is actually one of the most severely invaded of all vegetation types in South Africa.
Another threat is the prevention of the seasonal fires that naturally sweep the area every few years, replenishing and revitalising the vegetation. Without the fires, the fynbos plants grow old and die, and their seeds cannot germinate. The areas of dense
Afrotemperate forest then expand and replace the fynbos.[4]
Some of the plants that are
endemic to this vegetation type and occur nowhere else are: