René Gaigher, James Pryke & Michael Samways
Department Conservation Ecology & Entomology, Stellenbosch University
I
n the past, nature conservation
and agricultural production
have been considered to be
competing land-uses, but there
is growing recognition that they
can be integrated in ways that can
be mutually beneficial. Conserving
biodiversity in farmland can make a
huge contribution to regional conservation, especially in the megadiverse Cape Floristic Region (CFR)
where high levels of biodiversity still
exist in farmland. This can also benefit production. Long-term sustainable agriculture relies on the important ecological functions provided by biodiversity, such as pollination, pest regulation and nutrient
cycling. The Department of Conservation Ecology and Entomology at
Stellenbosch University is studying
how biodiversity can be effectively
conserved in CFR farmland, especially on wine farms, which dominate the area. We focus on insects
and other arthropods, as they are
sensitive indicators of changes in
land-use practices and are also
some of the most important service
-providers in all terrestrial and
aquatic ecosystems. Here are some
of the key principles that have
emerged from studies over the last
few years:
The value of natural vegetation
remnants
Remnant patches of fynbos and
Renosterveld are extremely valuable
for farmland insects, as they provide critical food resources (such as
nectar, pollen and a variety of prey
organisms) that insects need to
complete their life cycle. They are
also refuge areas where insects can
overwinter, mate and lay eggs, and
escape the disturbances in the agricultural landscape. These remnants
have much higher insect diversity
than any other habitat in these
farmland mosaics, and we’ve seen
this for a wide variety of groups
such as monkey beetles, ants, bees
and wasps, as well as for the flowering plants that many of them depend on. Not only are remnants
rich in biodiversity, but individual
patches can contain distinct combinations of species that are not
found in the rest of the landscape,
which emphasises the unique value
and irreplaceability of each remnant.
Conservation of remnant vegetation