Physico-chemical characteristics of soils at selected water-points in the Etosha National Pan, Namibia

Abstract

National parks are important systems for protecting biodiversity and ecosystems around the world. In Namibia, approximately 19% of the country’s land surface is proclaimed for protected areas including Etosha National Park (ENP). Managing the protected areas effectively and sustainably requires a great understanding of various components of the park, including the soils. This study aimed to understand the soil properties at different water-points in ENP (at Mushara, Rietfontein and Ombika water-points). Ten plots from each site were sampled, at different soil depths. Soil parameters such as soil texture, pH, electronic conductivity (EC), Cation Exchange Capacity (CEC), phosphorus (P), potassium (K) and organic matter content (OM) were measured and analysed. The results show that soils were poorer at Mushara than at Rietfontein and Ombika, in terms of OM, Zinc (Zn), EC, Iron (Fe), and CEC. Furthermore, Mushara had significantly more sand content than both Ombika and Rietfontein. However, there were no significant differences between Rietfontein and Ombika in terms of CEC, Zn, Calcium (Ca), pH, OM, iron, manganese, sodium (Na) and soil texture. All sites were largely dominated by sandy soil. However, Mushara had significantly more sand than both Ombika and Rietfontein, and significantly lower clay and silt content than Ombika and Rietfontein. The study concludes that the soil properties at assessed water-points might be influenced by vegetation communities, soil type and the total annual precipitation. Therefore, the results of this study can be used to refine conservation strategies and develop long-term monitoring programs. We recommend that future studies focus on the link between vegetation composition, above and below ground biomass and soil properties in ENP.