Distribution of termites (Isoptera) throughout Namibia - environmental connections
Termites contribute greatly to the functioning of ecosystems. as effective soil modifiers and transformers of energy they are of particular importance in arid systems, adding to soil fertility and energy flow. Loss of biodiversity is a worldwide concern and loss of termite genera, as well as changes in generic distribution and composition of termite communities, may impair ecosystem health. The question is whether climatic variability and/or changes in land-use affect termite communities. In this study, based on the data of the Namibian National Survey of Isoptera which was conducted between 1964 and 1968, the distributions of termite genera were mapped using a Geographic Information system. Distribution maps of generic richness, as well as guilds based on feeding and nesting characteristics, have now been derived for Namibia using the above data. Distinct distribution patterns of individual genera as well as guilds are discernible. In order to ascertain whether termite community patterns would possibly alter in relation to climatic change, relationships between rainfall and the distribution of individual termite genera were established. It was found that individual genera show distinct associations with rainfall. Four genera recorded from Namibia show a negative association with increasing rainfall, while 22 genera are positively associated. Generic richness increased with increasing rainfall. The comparison of two rainfall models derived for the periods 1952-'67 and 1978-'93 shows that average rainfall in Namibia has declined over the past decades. The possible implications of such changes for termite distribution patterns are hypothesised. Continuous studies of termite ecology are important both scientifically and for the future welfare of arid ecosystems and human environments in Africa.
Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Science, 1997