Mpumalanga Biodiversity Conservation Plan Handbook - bgis-sanbi

MPUMALANGA BIODIVERSITY CONSERVATION PLAN HANDBOOK
10
Common Greenshank
Tringa nebularia
Most species are
completely dependent on
a narrow range of
environmental
conditions and the food
and shelter offered by
those conditions. Even
small changes can have
lasting and devastating
effects on whole
populations. Birds like
the migrant greenshank
are not rare but they are
restricted to feeding in
water between about
40mm and 120mm deep.
TABLE 3.1 Extent of Mpumalanga’s three biomes.
BIOME TOTAL SIZE (km 2 ) % OF REMAINING %TRANSFORMED
MPUMALANGA NATURAL
TRANSFORMATION
Transformation refers to the removal or radical disturbance of natural vegetation, for
example by crop agriculture, plantation forestry, mining or urban development.
Transformation mostly results in a serious and permanent loss of biodiversity and fragmentation
of ecosystems, which in turn lead to the failure of ecological processes. Remnants of
biodiversity may survive in transformed landscapes.
The MBCP transformation layer was created by merging the 1995 and 2000 National Land
Cover maps. These maps were created from satellite images that had been classified (by the
CSIR and ARC) into various land-use types, using remote sensing techniques. The MBCP
transformation layer is the best available representation of lost natural habitat based on
composite, six-year-old data. The composite layer was cross-checked against a false-colour
satellite image taken in 2000, allowing mis-classified areas to be corrected.
GRASSLAND
Grassland defines itself: landscapes dominated by grass. Although grasses are the most visible
plants, grasslands have a higher diversity than other herbaceous species, especially those with
below-ground storage organs such as bulbs or tubers. These plants produce many of our
spectacular wild flowers and contribute to biodiversity that is second only to the Cape Fynbos
in species richness. Grassland species are particularly well adapted to being defoliated,
whether by grazing, fire or frost. Repeated defoliation, within reason, does no real harm to
such plants nor does it reduce productivity.
African grasslands are particularly old, stable and resilient ecosystems. Most plants are
perennials and surprisingly long lived, with very few annual species, which are the pioneer
plants needed to repair disturbance. This makes our grasslands vulnerable to destruction by
cultivation; once ploughed they are invaded by weedy pioneer plants that are mostly alien.
Although many grassland plants do produce seed, very little germinates, most being used as
vital food for their rich rodent and insect fauna.
Mpumalanga’s grasslands are mainly found in the highveld above 1000m. These are cool,
M P U M A L A N G A
VEGETATION (km 2 )
Grassland 531 61% 298 44%
Savanna 338 39% 255 25%
Forest 40 0.5% 39 1%
Total 874 100% 558 36%
dry open landscapes, with rainfall of over 500mm/yr. Frost, hail storms and lightning strikes
Biodiversity
are common. It is the natural occurrence of fire and these other defoliating events that favour
grassland plants over woody species and help maintain the open treeless character of grasslands.
Grasslands have shallowrooted vegetation with a growing season limited to about six
months of the year. The nongrowing seasons are characterised by cool and dry conditions,
during which time most foliage is removed or killed by frost, and dies back to ground level.
CONSERVATION PLAN HANDBOOK