The ephemeral pans of Gras-Holpan: Mokala National Park, Northern Cape, South Africa

Abstract

assemblages. A total of five pans were measured in the Northern Cape province of South Africa located on the Savanna and Nama-Karoo biomes within a 4500 ha area. The measurements taken included water quality variables (pH, salinity, total dissolved solids [TDS]), taxon diversity and richness of macro-invertebrates and aquatic birdlife. Evaporation rate between the pans varied with time. There was a difference in the macro-invertebrate taxon richness between the pans. Macro-invertebrate taxon succession was observed over time and some macro-invertebrates showed confinement to pans of a particular biome. It was found that pH was significantly the most contributing factor to the taxon richness and diversity of the macro-invertebrates recorded, while the salinity and TDS increased with time as water evaporated. Conservation implications: The shrimps (fairy, clam and tadpole) were unique to the Nama-Karoo pans. It was found that pH ( p < 0.05) was the most contributing factor to the taxon richness and diversity of the macro-invertebrates recorded, and salinity and TDS increased with time as water evaporated.