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Wild biodiversity
The wide range of biomes and
habitats in southern Africa yield a spectacular array of wildlife. The
term 'wildlife' really comes to much the same thing as 'wild biodiversity' yet
it has tended to be used more for the life one encounters in conservation areas
such as national parks. Wild biodiversity is about all forms of life from
bacteria through to lions that are encountered in natural, rather than
human-made, habitats.
The three main wild biodiversity realms
There is a relatively sharp division between the life
found on land (terrestrial biodiversity) and the life found in our oceans
(marine biodiversity). For instance among the arthropods, the crustaceans
dominate in the oceans whereas the insects dominate on land. Among plant-like
forms, there are the seaweeds in the oceans and the seed plants on land. In-between
these two extremes is the freshwater
biodiversity in rivers and lakes. Some insects,
such as dragonflies, have immature stages that live in freshwater and adults
stages that live on land, so the interface between freshwater and land is not as
sharp as between seawater and land.
Marine biodiversity
There are over 10 000 species of marine plants and
animals around the coast of southern Africa, constituting about 15% of the
coast marine species known worldwide. Part of the reason for this high
diversity is that the west, south and east coasts of southern Africa
experience different currents and water temperatures, resulting in three
main biodiversity 'provinces'. In addition, off shore there are the
pelagic species living in the surface waters where there is light
penetration, and the deep benthic species living in subdued to dark
conditions on the ocean floor and relying mainly on organic matter coming
down from above.
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Freshwater biodiversity
Freshwater is a great limiting factor within
southern Africa. Most of the region is arid and many rivers and lakes are
ephemeral in nature. Some organisms are specially adapted to these
ephemeral systems, being able to go into aestivation during the dry
periods. However, there are also substantial perennial rivers, streams and
lakes as well as man-made dams, and these systems yield a rich array of
organisms. Disruption of the ecology of the organisms in these systems
through pollution, siltation or nutrient loading, can have a devastating
effect on the health of these systems, which impacts directly on supply of
freshwater to human populations.
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Terrestrial biodiversity
Diversity of topography, geology, soils, moisture
and temperature within southern Africa yields an impressive diversity of
life adapted for life on land. Southern Africa is one of the most
botanically rich regions in the world with the fynbos, succulent
karoo and being particularly rich in endemic species. Woodland and subtropical elements extend into southern
Africa from further north and yield a diverse assemblage of plants and
animals that can be observed in famous tourist destinations such as the
Kruger National Park.
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About wild biodiversity
The term 'wild biodiversity' is used here in a loose sense
to refer to biodiversity that one encounters in natural habitats. This is to
distinguish it from other sections of Biodiversity Explorer that deal with
biodiversity we encounter in man-made habitats such as cities, towns, gardens
and farms. Hence wild biodiversity makes up the vast majority of life
forms in a region like southern Africa yet most people spend so little time in
natural habitats that it is the least encountered form of biodiversity.
Hopefully the information presented here will encourage you to explore wild
biodiversity by getting out into the country and observing what is around
you.
There is obviously overlap between the biodiversity in
natural areas and that in man-made habitats yet many people are now living in
urban habitats that have little vegetation in them and from which wild
biodiversity is excluded through use of pesticides or through the insidious
effect of pollutants. Hopefully with time we will see the errors of our ways by
reverting back to making the habitats we live in more suitable for other forms
of life that we can enjoy. Some people are already doing this through growing
indigenous plants in their gardens and avoiding the use of
pesticides.
The term 'wildlife' really comes to much the same thing as
'wild biodiversity' yet it has tended to be used more for the life one
encounters in conservation areas such as national parks. Hence 'wildlife' often conjures
up visions of animals like lions that can eat you unless you are sitting safely
inside your car. Wild biodiversity is about all forms of life from bacteria
through to lions. While you can't see bacteria directly unless you have a high
powered microscope, you can see their effects through the diseases they cause in
other organisms or through the symbiotic relations they have with other
organisms. As an example of the latter, most termite species are dependent on
bacteria to turn plant cellulose into substances that can be easily digested.
Without such bacteria there would be no termites and none of the large diversity
of organisms that depend on termites. So when we see an organism like a termite,
it leads to a whole cascading series of relationships with other organisms. In
Biodiversity Explorer we try to link in to these other relationships and show
how all of life on earth is linked in some way or other.
All forms of biodiversity including us humans were once
'wild'. Over thousands of years, we have become domesticated in our ways by
domesticating a narrow range of wildlife that can provide us with food and
security (see other sections of Biodiversity Explorer, accessible from the home
page, that deal with domesticated forms). However, the process of domestication
has not stopped. There are many plants and animals that are currently in the
process of being domesticated. The Ostrich and the Marula tree come to mind as
examples.
We are also still very dependent on wild biodiversity. For
instance, most of the medicines we use are derived from chemicals extracted from
organisms in the wild (mainly plants but also some animals, fungi and bacteria).
Most of the fish we eat is derived from wild stock. We also depend on wild
habitats, in particular forests, to regulate the earth's atmosphere. We are
currently entering a crisis situation of where humans are shunting huge
quantities of carbon dioxide into the atmosphere (mainly through the burning of
fossil fuels) and plants are not managing to keep up through the photosynthetic
process of converting atmospheric carbon into solid carbon that makes up wood
and leaves. As a result of this excess carbon in the atmosphere, global warming
is happening, which is changing sea levels, rainfall patterns and many other
phenomena. Besides causing the extinction of many species, global warming will
disrupt many human communities and cause suffering, death and destruction. For
the sake of our own survival, we cannot afford to destroy natural habitats on
earth that play this pivotal role and we also need to live more responsible,
less resource consuming, life styles. Our oceans also play a pivotal role in
regulating the earth's atmosphere and we also need to ensure that they are kept
healthy.
Besides the fact that we are dependent on wild
biodiversity, we also need to develop a respect for life forms other than our
own. We have no right to destroy other species of life on earth. It sounds clichéd
but just as we do need to learn to live in harmony with ourselves, we need to
learn to live in harmony with nature - our survival and quality of life depends
upon it!
This section of Biodiversity Explorer is still in its
infancy. It focuses mainly on conservation areas such as nature reserves and
national parks but sometimes it goes beyond this to feature unprotected areas
that offer interesting experiences of the life around us.
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