Abstract
Karst ecosystems generally comprise of highly specialized troglofauna with certain preadaptations which enable them to survive in karst environments. The organisms in karst ecosystems form detritus-driven food webs which are unique to each karst system. There is also a high degree of local endemism, which in conjunction with micro distributions, generally results in an increased risk of extinction for these cavernicolous communities. Little is known of the biodiversity of South African troglofauna, with identification of cave dwelling arthropods and the description of their behaviour in the karst system being few and far between. With increasing anthropogenic pressures on karst systems, direct or indirect, through quarrying, groundwater abstraction, illegal dumping, urbanization etc., the rate of species extinction in these karst environments is faster than the rate of species discovery and description. This warrants the prioritisation of biodiversity studies and the conservation of karst ecosystems. However, to develop effective management programs for troglofauna, baseline knowledge of the species richness is required, including a sound understanding of the biotic and abiotic factors influencing community dynamics. This study established a baseline biodiversity index for troglophilic arthropods associated with guano in Bakwena Cave, Grobler’s Cave and Kemp’s Cave, by developing standardized methodologies for determining the community structure and estimating population sizes. This project also includes a study of the succession of guanophilic arthropods within a decomposing guano pile. The various food-webs associated with the guano in the different caves in order to determine predator-prey relationships, population sizes of the various trophic levels, and the degree of prey specificity among predatory species are discussed. The daily and seasonal variation in climatic conditions within these caves as well as fluctuations in the size of and diversity within cavernicolous populations in response to these seasonal cycles are also discussed.
M.Sc. (Zoology)