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Biodiversity is a contraction of the term
biological diversity. The United Nations Convention on Biological
Diversity defines biodiversity as "the variability among living
organisms from all sources including terrestrial, marine and other
aquatic ecosystems, and the ecological complexes of which they are
part; this includes diversity within species, between species and of
ecosystems". Biodiversity is essential to human survival,
yet its value remains largely unrecognised.
The Northern Cape cannot afford to lose its
biodiversity asset. Despite having low population densities,
there are many challenges facing biodiversity management and
conservation. These need to be addressed in a systematic manner in
order to ensure the sustainable use of natural resources and the
continuance of this heritage and attraction for future generations.
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| Habitat change |
The loss, transformation and degradation of
natural habitat is one of the most important causes of
biodiversity loss. Conversion of natural habitat types by
cultivation, grazing, urban developments, afforestation, mining,
dams, industry and alien plant invasions results in substantial
ecosystem degradation
and species loss.
Sensitive arid areas
such as the Succulent Karoo Biome of
the Northern Cape are particularly prone to degradation through over-grazing,
invasive alien species and mining. In addition, the
aridity of the climate slows recovery of degraded areas. The Northern
Cape is the third most degraded province in South Africa, after
the Limpopo Province and KwaZulu-Natal. The
selected indicator is:
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| Conservation of biodiversity |
Of the seven biomes found in South Africa,
five are
represented in the Northern Cape. These are the
Savanna, Nama Karoo, Succulent Karoo, Grassland and Fynbos Biomes. Approximately 20
vegetation types are recognised within these biomes. In
addition, there are 18 centres of endemism within
South Africa, of which 8 are found within the Northern Cape:
the Kamiesberg, Gariep and Hantam-Roggeveld centres fall almost exclusively within the
Province, making their protection in the Northern
Cape
even more important.
In order to ensure the effective conservation
of biodiversity, a rational and consolidated system of formally
protected areas is essential. This is measured
through the indicator:
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| Species diversity |
South Africa is the third
most biologically diverse country in the world, containing between 250 000 and 1 000
000 species. These species provide people with resources that
supplement their livelihoods. Yet, plant and animal species are
over-utilised and between 14% and 37% of plant, bird, reptile, amphibian, mammal and
butterfly species are
listed as threatened.
The impact of decline or loss of species on
ecosystem services is a complex relationship and is difficult to
measure. Some species are known to play a more significant role
within the environment than others (known as keystone species). The
loss of one of these species has a particularly disruptive effect on
ecosystem goods and services. Species diversity is
therefore monitored using:
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| Alien invasive species |
Invading alien organisms pose the second
largest threat to biodiversity after direct habitat destruction.
They are a threat to
indigenous species through:
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displacement
by direct competition;
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reduction
of structural diversity;
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disruption of the
prevailing vegetation dynamics;
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impacts on fire regimes due to
increases in biomass;
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alteration of
local hydrology; and
-
modification
of nutrient cycling.
At current rates of expansion in
South Africa (5% per annum), the extent of alien invasive species could
double in fifteen years. This is measured in the
Northern Cape by:
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| Resource value and use |
Whilst
biodiversity should be conserved because
of the value of the biological resources,
goods and services they provide, the economic contribution of
biodiversity cannot be underplayed. Tourism is one of South Africa's
national priorities due to its potential to stimulate
economic growth
and create jobs.
The sustainable use of biological resources
is undermined by being undervalued and therefore overused. The trade
in flora and fauna reveals not only the value of natural resources
but also some of the difficulties encountered when striving to
practice sustainable use:
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| Resource management |
Biodiversity is no longer an issue confined
to conservation or wildlife supporters. Its importance to farmers,
indigenous people, human rights and global trade issues is
now well recognised.
The effective protection and use of
biodiversity within the Northern Cape requires sound management.
However, serious constraints to this may include insufficient
skills, expertise or funding, legal fragmentation and weak political
commitment. The indicator selected in
this report is:
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