The CMA is located within the Cape
Floristic Region (CFR) which is rich in biodiversity. The CFR contains some 8 500
indigenous flowering plant species (Bond and Goldblatt, 1984; Cowling et al., 1992) even
though the total surface area is only roughly 89 000 km2 (some 4% of the total surface
area of southern Africa). This area has been identified as a conservation
"hot-spot" (Myers, 1990) of international significance.
Sixty-eight per cent of plant species in the CFR are endemic (found nowhere else) and the
CFR has the distinction of being regarded, in its own right, as one of six floristic
kingdoms on Earth (Bond and Goldblatt, 1984), with three centres of diversity and endemism
found within or bordering the CMA (see Table 1). This unique
environment supports a rich diversity of fauna, namely birds, mammals, reptiles,
amphibians and invertebrates. |
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| Contents of CONTEXTUAL INFO on Terrestrial
Ecosystems: |
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| Flora |
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The Cape Peninsula contains some 2 256 species of indigenous plants. At
least 90 of these are endemic to the Peninsula and some 141 species are listed as Red Data
Book species. On the Cape Flats, 82 Red Data Book species are found as well as about 26
endemic species. By 1994, a total of 294 plant species in the CMA were classified as being
in immediate danger of extinction. There are three distinct centres of diversity and
endemism within or bordering on the CMA (Hall and Veldhuis, 1985). These are the Cape
Peninsula, the Cape Flats and the Darling-Dassenberg area (see Map
1).
Four main vegetation types occur in the CMA, namely Sand Plain Fynbos; Renosterveld;
Strandveld and Mountain Fynbos. Sand Plain Fynbos, Renosterveld and Strandveld are lowland
vegetation types.Table
1 provides a summary of the status of lowland vegetation types within the CMA.
Mountain fynbos is not included because this vegetation type has been significantly less
affected than lowland vegetation and is well conserved within the Cape Peninsula National
Park. Whereas lowland vegetation is mainly under threat from urban development, Mountain
Fynbos is threatened by invasive alien plant species particularly on the Cape Peninsula (Table 2).
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|
| VEGETATION TYPE |
% DESTROYED |
% ALIEN |
% REMAINING |
% CONSERVED |
| Sand
Plain Fynbos |
>89%
(in CMA) |
10%
(in CMA) |
<1%
(in CMA) |
<<1%
(in CMA) |
| WC
Renosterveld |
97%
(total) |
>22%
(in CMA) |
3%
(total) |
<0.5%
(total) |
| Strandveld |
58%
(in CMA) |
10%
(in CMA) |
32%
(in CMA) |
<<10%
(in CMA) |
|
|
Alien vegetation was introduced to the CMA from foreign continents such as
Australia, Europe and North America mainly for the stabilisation of sand dunes. Species
introduced include Pines (e.g. P. radiata, P. pinaster), Gum trees (Eucalyptus species)
and Acacia species such as Port Jackson Willow, Rooikrans and Long-leaved Wattle (A.
saligna, A. cyclops and A. longifolia) (Erasmus, D., Erasmus, C. and Goodall, J. 1997).
These plants have their origins in environments similar to that of the Western Cape. Given
this and the absence of natural predators these species have spread and produced rapidly,
becoming some of the most invasive plant species in the CMA. Invasive alien plants disturb
the natural ecology, compete for resources with indigenous plants and significantly reduce
water run-off. However, certain non-invasive alien plants have been used for greening the
city and add to the aesthetic appeal of many areas. Trees such oaks, stone pines and
palms, for example, have become an important element of the urban landscape.
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| Fauna |
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| The CMA has numerous indigenous animal species, including high diversities
of butterflies, amphibians and reptiles. As the vegetation habitat has become reduced and
fragmented, so habitats for the associated fauna have declined. Habitats may range from a
single bush to a complex plant community, or from a "home range" many kilometres
in extent to a cave on the slopes of Table Mountain. |
| Mammals |
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Due to infertile soils, the vegetation of the CMA does not support large
numbers or a variety of mammals. Most of the larger mammal species which once existed on
grazing in lowland areas have been excluded from the Cape Metropole (Skead, 1980).
Numerous medium and smaller mammal species do however, remain. The rooikat, porcupine,
Chacma baboon and steenbok are some of the larger mammal species that still range free
outside reserves. A small herd of three hippopotami have been re-introduced to
"Zeekoevlei" in the Rondevlei Nature Reserve, Grassy Park. The small area of the
reserve has limited the herd size. A greater area is required for a successful breeding
programme. The decrease in numbers and variety of predators such as snakes, mongooses and
raptors leads to an increase in rodent species, potentially at the expense of vegetation.
For example, numbers of rock dassie, if unchecked, are able to significantly reduce plant
material.
Numerous mammal species have been introduced to the Peninsula over the past centuries.
These include the Himalayan Tahr, bontebok and Burchell's Zebra and are present within the
borders of the Cape Peninsula National Park. The presence of domestic animals (especially
feral cats and dogs) in and around conservation areas pose a threat to indigenous species.
Approximately, 41 mammal species have been recorded, or are likely to occur on the Cape
Peninsula, none of which appear in the South African Red Data Book for Mammals.
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| Avifauna (birds) |
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Numerous bird species that utilise the CMA as a permanent home or
migratory destination are under threat from urbanization (Brooke, 1984). The CMA, and more
specifically the Cape Peninsula, provides a variety of habitats for birds. There are birds
adapted to life in open fynbos veld such as the Orangebreasted Sunbird, Cape Sugarbird,
Grassbirds, Cape Siskins and Cape Francolin), natural forest (e.g. Sombre Bulbul, Cape
Batis, Kynsna Warbler and Redcrested Cuckoo) and rocks and cliff-faces (e.g. Cape Rock
Thrush, Rock Pigeon, Black and Alpine Swifts, Rock Kestrel and Black Eagle).
Coastal areas of the CMA also support birds such as Kelp and Hartlaub's Gull, Cape, Bank,
Crowned and Whitebreasted Cormorants, African Black Oystercatcher, and several Tern
species, whereas freshwater vleis provide a habitat for Egyptian and Spurwinged Geese,
African Black Duck and Yellow-billed Duck. Even the built-up areas of the CMA create a
habitat for a number of bird species. The Cape Flats Waste Waterworks, along the False Bay
coast, is rated as the fifth most important waterbird habitat in South Africa and is a
potential Ramsar site. It is widely known and highly regarded as a prime birdwatching site
but has no official conservation status.
The Cape Peninsula supports 155 regularly breeding bird species. Of these, eight are
listed in the South African Red Data Book for Birds. A loss of habitat has caused the
exclusion of some species, such as the Grass Owl, from the CMA. Certain alien bird
species, such as the House Crow and Mallard Duck, are associated with urban areas. Both
are competing with locally indigenous species and the latter is interbreeding with
indigenous species.
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| Amphibians |
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The numerous permanent and temporary wetlands as well as waterbodies such
as dams and rivers throughout the CMA, harbour numerous amphibian species. Several of
these species are listed in the Red Data Book (Branch, 1988). These include the Arum lily
frog, the Cape Rain frog and the Ghost frog. The Cape river frog is plentiful next to
streams and rivers.
Of the 18 species recorded on the Cape Peninsula, four are listed in the South African Red
Data Book for Reptiles and Amphibians. Their status is classified as follows: three
endangered and one vulnerable.
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| Reptiles |
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At least one species occurring on the Tygerberg, namely the Cape dwarf
chameleon, is endemic to the south-western Cape. In the Tygerberg area over 34 reptile
species have either been recorded or are likely to occur (Wood and Low, 1993). The
geometric tortoise is endemic to the few remaining patches of renosterveld on the Western
Cape lowlands.
The Cape Peninsula also offers a variety of habitats for several species of lizards such
as the koggelmannetjie and the black Cordylus cordylus. On the Peninsula two snake species
are listed by Branch (1988) as Red Data Book species, namely the Cape Sand Snake and the
Yellowbellied House Snake. Although snakes control pests, thus playing a useful role in
the broader ecosystem, they are often killed on sight.
Some 48 snake, lizard and tortoise species have been recorder on the Cape Peninsula. Of
the five reptile species mentioned in the South African Red Data Book on Reptiles and
Amphibians, one is endangered, one is vulnerable and three are rare.
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| Invertebrates |
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Research on invertebrates (Claassens and Dickson, 1980 and Picker and
Samways, 1996) has identified some 111 endemic invertebrate species in the Cape Peninsula.
The presence of at least four Red Data Book butterfly species (Henning and Henning, 1989;
Wood and Low, 1993) on the Tygerberg, as well as the fact that the CMA is the centre of
diversity for butterflies and other organisms, renders the CMA an important site for
conservation of invertebrates. Some 75 species of butterfly occur on the Cape Peninsula.
Vegetation in the CMA, and more specifically indigenous flowering plant species provide
food for a variety of invertebrates including beetles, bees, ants and spiders.
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| Conservation of natural habitats |
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Conservation
in the CMA is very important, given the high biodiversity and endemism in the area. The
CMA is also an area of spectacular scenic beauty that attracts many visitors. There are a
number of nature reserves and bird sanctuaries across the CMA. For additional information
pertaining to Marine Protected Areas around the CMA, (see Marine
& coastal ecosystems). The key conservation areas in the CMA are listed in Table 2 and shown in Map 2.
In 1997, the Botanical Society based at Kirstenbosch National Botanical Gardens undertook
a study of 47 botanical sites. From these, 15 core sites on the Cape Flats requiring
comprehensive conservation were identified, nine of which have some form of conservation
status at present. The conservation status of the nine sites consists of:
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- two natural heritage sites (Plattekloof, Six
Base Ordinance)
- one provincial nature reserve (Driftsands
Nature Reserve)
- two local authority reserves (Wolfgat Nature
Reserve, Rondevlei Nature Reserve)
- one private nature reserve (Cape Flats
Nature Reserve)
- a national monument (Rondebosch Common)
- a reserve owned by the National Botanical
Institute (Edith Stephens Nature Reserve)
- one site which has still to have its status
confirmed (Rietvlei)
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| The
six sites, which still require official protection, are Milnerton, Kenilworth, and
Durbanville Race Courses, the Macassar Dunes, the N1-N7 interchange and Swartklip. These
15 sites would conserve over 80% (40 out of 48) of Red Data Book botanical species
(McKenzie and Rebelo, 1997). It should be noted that the Botanical Society study excluded
renosterveld vegetation as well as additional conservation worthy sites in the eastern
section of the Cape Flats. Map 2 shows all the conservation
areas in the CMA, including some Marine Protected Areas.
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|
NAME |
SIZE (ha) |
CONSERVATION FOCUS |
| Cape Flats
Private Nature Reserve |
21 |
fauna and flora |
| Cape of Good Hope
Nature Reserve |
7
750 |
fauna and flora |
| Durbanville
Nature Reserve |
6 |
fauna and flora |
| Duiker Island |
- |
seals and marine
birds |
| Kirstenbosch
National Botanical Gardens |
828 |
Flora |
| Miller’s
Point Marine Reserve |
- |
marine fauna |
| Orange Kloof |
285 |
fauna and flora |
| Raapenberg Bird
Sanctuary |
10 |
freshwater and
marine birds |
| Rietvlei Bird
Sanctuary |
- |
Waterfowl
|
| Robben Island |
574 |
marine birds and
west-coast strandveld |
| Rondevlei Nature
Reserve |
200 |
waterfowl and
flora |
| Seal Island |
2 |
Seals |
| Silvermine Nature
Reserve |
2
158 |
fauna and flora |
| Table Mountain
Nature Reserve |
2
904 |
fauna and flora |
| Tokai Forest
Nature Reserve |
2
572* |
fauna and flora |
| Tygerberg Nature
Reserve |
67 |
fauna and flora |
| Wolfgat Nature
Reserve |
248 |
marine fauna |
| Zandvlei Bird
Sanctuary |
20 |
Waterfowl |
| Helderberg Nature
Reserve |
244 |
fauna and flora |
| Cape Peninsula
National Park |
16
000 |
fauna and flora |
| Cape Peninsula
Protected Natural Environment |
29
100 |
fauna and flora |
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| The Cape Peninsula |
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The
Cape Peninsula has been the focus of conservation in the CMA as it contains the highest
density of plant species, endemic plant species and threatened species of any similarly
sized area on earth. In the 1990's over 60% or 291 km2 was awarded some protection from
development. The conservation status of parts of the area, called the Cape Peninsula
Protected Natural Environment (CPPNE), was elevated by the creation of the Cape Peninsula
National Park on 29 May 1998 (Map 2). This national park is
under the management of the South African National Parks and currently covers
approximately 16 000 ha. It is likely to incorporate more land within the next five years,
expanding to approximately 30 000 ha. The Global Environmental Facility is funding the
Cape Peninsula Biodiversity Conservation Project that aims to conserve indigenous fauna
and flora.
Furthermore, the Cape Peninsula National Park is unique in that it is situated within a
growing metropolitan area and shares a common open boundary with public and private
landowners. In order to ensure effective conservation of fauna and flora within the CMA,
management initiatives need to take cognisance of urban context.
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