Abstract:
As part of the second phase of the South African National Survey of Arachnida (SANSA),
field surveys were conducted in many degree-square grids throughout the country using a
standardised rapid sampling protocol. This study reports on the arachnid diversity of the
Ophathe Game Reserve (OGR) in northern KwaZulu-Natal, as found during a preliminary
survey in June 2007 (mid winter) and a SANSA field survey in October 2008 (mid spring) in
four representative habitats. The SANSA survey included seven sampling methods: pitfalls,
beating, sweep-netting, litter sifting, hand collecting, night collecting and Winkler traps. A total
of 282 species in six arachnid orders were collected during the two surveys, of which spiders
were the most species-rich order (268 species in 47 families). The SANSA survey yielded 966
adult arachnids, representing six orders and 197 species, with a further 67 species represented
only by immatures. Although adult arachnid abundance (n) differed considerably between
the four habitats (range: 156–321), adult species richness (Sobs) was less variable (range: 65–85).
These survey results are comparable with several longer-term surveys in the Savanna biome,
and indicate that the SANSA sampling protocol can yield an impressive diversity of arachnids
during a relatively short period of sampling, with a high level of coverage (> 0.8 for sites
and most sampling methods) and moderate levels of sample completion for adults (> 0.55
for all sites), despite logistical and temporal challenges. Additional repetitions of the SANSA
sampling protocol in other seasons will likely increase biodiversity knowledge of arachnids in
OGR considerably.
CONSERVATION IMPLICATIONS : The implementation of rapid sampling protocols in an atlas
project is essential to generate a large volume of species-level data. The SANSA protocol is an
efficient means for rapidly generating arachnid data, and in future will allow for an assessment
of diversity patterns in degree-square grids across South Africa.
