Diversity and density of ground-dwelling spiders in Dwesa Nature Reserve, Eastern Cape, South Africa

Biodiversity is the source of essential goods and ecological services that constitute the source of life for all; despite this there are still some major gaps in our knowledge of biodiversity. One such gap is that of the diversity of spiders in many areas. Knowledge of spider communities is important for a number of reasons i.e. terrestrial arthropod communities are likely to be shaped by spiders as they are at the top of invertebrate trophic levels and can be employed as useful indicators of environmental health. Studies show that spider diversity and density are related to habitat structure. We therefore report on the diversity and density of ground-dwelling spiders in the former Transkei region. Three habitat types were identified and pitfall trapping was employed as a sampling method. A total of 180 individuals from 11 families were collected with family Ctenidae being the most abundant. Alpha, beta & gamma diversities and Simpson’s and Shannon-wiener indices were employed for the different habitats and variation in diversity when comparing different habitats was observed. Results show that habitat selection does affect both diversity and density; with the grassland habitat with highest diversity and riverine habitat with highest density of ground-dwelling spiders.