The
Grassland Biome is found chiefly on the high central plateau of
South Africa, and the inland areas of KwaZuluNatal and the Eastern
Cape. The topography is mainly flat and rolling, but includes the
escarpment itself. Altitude varies from near sea level to 2 850
m above sea level.
Grasslands (also known locally as Grassveld) are dominated by a
single layer of grasses. The amount of cover depends on rainfall
and the degree of grazing. Trees are absent, except in a few localized
habitats. Geophytes (bulbs) are often abundant. Frosts, fire and
grazing maintain the grass dominance and prevent the establishment
of trees.
There are two categories of grass plants: sweet grasses have a
lower fibre content, maintain their nutrients in the leaves in winter
and are therefore palatable to stock. Sour grasses have a higher
fibre content and tend to withdraw their nutrients from the leaves
during winter so that they are unpalatable to stock. At higher rainfall
and on more acidic soils, sour grasses prevail, with 625 mm per
year taken as the level at which unpalatable grasses predominate.
C4 grasses dominate throughout the biome, except at the highest
altitudes where C3 grasses become prominent.
Grass plants tolerate grazing, fire, and even mowing, well: most
produce new stems readily, using a wide variety of strategies. Overgrazing
tends to increase the proportion of pioneer, creeping and annual
grasses, and it is in the transition zones between sweet and sour
grass dominance that careful management is required to maintain
the abundance of sweet grasses. The Grassland Biome is the mainstay
of dairy, beef and wool production in South Africa. Pastures may
be augmented in wetter areas by the addition of legumes and sweet
grasses.
The Grassland Biome is the cornerstone of the maize crop, and many
grassland types have been converted to this crop. Sorghum, wheat
and sunflowers are also farmed on a smaller scale.
Urbanization is a major additional influence on the loss of natural
areas - the Witwatersrand is centred in this biome. The Grassland
Biome is considered to have an extremely high biodiversity, second
only to the Fynbos Biome. Rare plants are often found in the grasslands,
especially in the escarpment area. These rare species are often
endangered, comprising mainly endemic geophytes or dicotyledonous
herbaceous plants. Very few grasses are rare or endangered. The
scenic splendour of the escarpment region attracts many tourists.
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