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The opencast extraction of limestone at the PPC Cement (Pty) Ltd Loerie quarry in
the Eastern Cape, South Africa, has led to disturbance of the immediate
environment. Large tracts of thicket have been removed during mining and
exhausted quarry areas had to be revegetated. Revegetation
commenced 16 years ago and as a result of progressive revegetation efforts
since then, five seral stages were available for study. This presented an
opportunity to describe the successional progression that occurs where thicket
topsoil was used for revegetation. The quarry lies near the Gamtoos fault and
both thicket and mountain fynbos is found in proximity to the mine. Before
mining, the area was covered by thicket and quarry floors were revegetated by
covering landscaped areas with thicket topsoil. The vegetation that developed
in the quarry had a very low floristic relationship to fynbos. After 16 years,
the vegetation also had a low similarity to thicket, even though the soils used
for revegetation contained thicket propagules. The oldest seral stage (16
years) was a Rhus incisa– Panicum deustum thicket in which only 46% of
the species were mature thicket species. In order to develop thicket more rapidly,
active intervention will be required. This could take the form of planting of
saplings of key thicket species. A trial planting of such saplings showed high
survival success of most species. Long-term (50 year) monitoring will be
required to determine whether this approach was successful.

South African Journal of Botany 2003, 69: 434–445