27) BIODIVERSITY IN SOUTH AFRICA
Biodiversity describes the variety of life in an area, including
the number of different species, the genetic wealth within each
species, the interrelationships between them, and the natural
areas where they occur.
An immensely rich species diversity is found in South Africa.
With a land surface area of 1,1 million km2 - representing just
1% of the earth's total land surface - South Africa contains
almost 10% of the world's total known bird, fish and plant
species, and over 6% of the world's mammal and reptile species.
This natural wealth is threatened by growing human populations
and their demands on the environment.
WHY SUCH DIVERSITY?
South Africa has a wide range of climatic conditions and many
variations in topography (e.g. narrow coastal plain, steep
escarpment, large plateau). In combination, climate and
topography give rise to broad vegetation zones which, together
with their associated animal life, are called biomes. These are
the Karoo, fynbos, forest, grassland and savanna biomes. Each of
these supports its own collection of plant and animal species.
The Karoo, for example, is home to plants and animals well suited
to hot, dry conditions such as the gemsbok, and succulent plants.
Fynbos is home to a variety of plants that are suited to a
mediterranean climate and the poor soils of the south west Cape.
SOUTH AFRICA'S LIVING WEALTH
* Plants:
More than 20 300 species of flowering plants occur in South
Africa. One of the six most significant concentrations of plants
in the world is the Cape Floral Kingdom, with its distinctive
fynbos vegetation, in the south west Cape. Most of South Africa's
2 000 threatened plants are found in fynbos (see Enviro Facts
"Fynbos").
* Mammals:
In total 243 mammals are found in the region. There are 17
threatened species in South Africa, including the black rhino,
pangolin and giant golden mole. The riverine rabbit, roan
antelope and wild dog are endangered. Two mammals have become
extinct: the blue antelope and the quagga.
* Birds:
Of the more than 800 bird species, 26 are threatened, including
the jackass penguin, Cape vulture, martial eagle, bateleur and
Cape parrot. The 5 endangered species are: wattled crane, roseate
tern, Egyptian vulture, blackrumped buttonquail and blue swallow.
* Reptiles and Amphibians:
In total 370 reptiles and amphibians occur in the region, of
which 21 are threatened. Six of these are endangered.
* Fish:
220 freshwater fishes occur, of which 21 are threatened. There
are more than 2 000 marine fish species, for which no information
is available about threatened species.
* Insects:
80 000 insects are known to occur, many of which are endemic.
There are many more as yet undescribed species.
THREATS TO SOUTH AFRICA'S BIODIVERSITY
Unfortunately this immense natural wealth is under extreme
pressure resulting from human demands placed on the environment
through economic development, agriculture and urbanisation.
Invasive alien vegetation and the trade in wildlife also
contribute to the problem. (See Enviro-Facts "Biodiversity")
PROTECTION OF SOUTH AFRICA'S BIODIVERSITY
* Red Data Books or RDBs, are lists of threatened plants and
animals specific to a certain region. They are a vital source of
information in guiding conservation decisions. South Africa has
produced 5 RDBs dealing with each of the following: birds, land
mammals, fishes (fresh water and estuarine only), reptiles and
amphibians, and butterflies.
* Southern Africa has 582 national parks and nature reserves
covering 6% of the region. More than 90% of the region's birds,
mammals, amphibians, and reptiles occur in this network of
protected areas. However, only 34% of plants are protected. There
is an urgent need to extend the network of conservation areas to
include unprotected plants.
* The Convention on International Trade in Endangered Species,
or CITES, signed by 100 countries, including South Africa,
controls and in some cases prohibits the trade in threatened
species.
DESCRIBING THE CONSERVATION STATUS OF A SPECIES
The conservation status of a plant or animal species is described
by the following terms:
- EXTINCT: a species for which there is a historical record, but
which no longer exists in the area under review.
- ENDANGERED a species in danger of extinction, and whose
survival is unlikely if the factors causing its decline continue.
- VULNERABLE a species which it is believed will move into the
endangered category if the factors causing its decline continue.
- RARE a species with small populations, which are not yet
vulnerable or endangered, but which are at risk.
The term THREATENED is commonly used as a collective description
for species which are endangered vulnerable or rare.
Some species are ENDEMIC, i.e. they are restricted to one region
and occur nowhere else. A threatened endemic is a conservation
priority.
WHAT YOU CAN DO
* Demands for goods and services place pressure on the
environment - the less we use, the less severe the pressure. *
When a conservation issue rears its head, make your voice heard -
draw up a petition, contact your local MP, write to the
Department of Environment Affairs and liaise with your newspaper.
* Support a conservation organisation.
FURTHER READING
SOUTH AFRICA'S THREATENED WILDLIFE.
J. Ledger. Endangered Wildlife Trust, Johannesburg, 1990.
THE GAIA ATLAS OF PLANET MANAGEMENT.
N. Myers (ed). Pan Books, London, 1985.
GOING GREEN: PEOPLE, POLITICS AND ENVIRONMENT IN SOUTH AFRICA.
J. Cock and E. Koch (eds). Oxford University Press, Oxford, 1991.
SOUTH AFRICAN ENVIRONMENTS INTO THE 21ST CENTURY.
B. Huntley, R. Siegfried and C. Sunter. Human, Rousseau &
Tafelberg, Cape Town, 1989.
BIODIVERSITY.
E. Wilson (ed). National Academy Press, Washington D.C., 1988.
Enviro-Facts: "Why Conserve?" and "Biodiversity".
USEFUL ADDRESSES
Department of Environment Affairs and Tourism.
P/Bag X 447, Pretoria, 0001. Tel. 012-310 3425.
WWF-SA.
P.O. Box 456, Stellenbosch, 7600. Tel. 021-887 2801.
Endangered Wildlife Trust.
P/Bag X11, Parkview, 2122. Tel. 011-486 1102.
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