Environmental Effects on Coleoptera Diversity in the Maloti-Drakensberg Region

A general paucity of studies on the dynamics of invertebrate assemblages exists despite the pivotal role that they play in ecosystem functioning. Altitude and season play vital roles in determining the composition of invertebrate assembalges world-wide. Invertebrate abundance and species richness generally decrease with an increase in altitude and are normally highest in the wet season. Additionally, assemblage composition tends to change dramatically along an altitudinal gradient and between wet and dry seasons. This study investigated the changes that might occur in the composition of Coleoptera assemblages at a low and a high altitude site and between wet and dry seasons in the Sani Pass area of the Maloti-Drakensberg region bordering South Africa and Lesotho, where extremely steep altitudinal gradients and clearly defined seasons exist. Beetle assemblages differed dramatically in composition between altitudinal sites and between wet and dry seasons with relatively little overlap occurring. Studies on the dynamics and composition of beetle assemblages need to include altitudinal and seasonal variations in order to capture the entirety of the assemblages in question.