Abstract:
The Pondoland region of the Eastern Cape province, South Africa is very poorly studied with
regard to invertebrate diversity, particularly in the case of arachnids. Accordingly, and in
view of proposed infrastructural and mining developments in this ecologically sensitive area
of high plant endemism, baseline data are provided on spiders (Araneae) of the vegetation
layer (i.e. excluding the ground-dwelling fauna) of the Mkambati Nature Reserve (MNR).
Spiders were collected at 26 sites (six forest and 20 grassland sites) in the MNR over an
eight-day period, using sweep sampling and active searching of flowers in grassland and
tree beating in forests, as part of a broader biodiversity survey. Additional specimens were
collected with Malaise and pan traps. A total of 1275 specimens were sampled, representing
132 species (6.6% of the total number recorded in South Africa) in 103 genera and 29 families.
Theridiidae and Araneidae were the most diverse spider families in the reserve, represented
by 22 species each (16.7% of the total), followed by Thomisidae with 19 species (14.4%) and
Salticidae with 18 species (13.6%). Grassland and forest had distinct spider faunas, with only
24.2% of species being recorded from both biomes. The average number of species sampled
per site in grassland and forest was 26 species for both habitats, although values for the two
biomes are not directly comparable because different sampling methods were used. All 132
species are new records for the reserve, of which 20 were new records for the Eastern Cape
and at least eight spider species may be new to science. The spider diversity captured despite
temporal and methodological limits indicates that many additional species are likely to occur
in the reserve. CONSERVATION IMPLICATIONS: If the MNR is not adequately conserved at least five new species,
which may be confined to the area, would be at high risk of extinction and 15 other species
endemic to the Pondoland and KwaZulu-Natal region would have their risk of extinction
increased.
