Peatland substrates in northern KwaZulu-Natal: a study of the forming environments, properties and an approach towards classification

<p>Peatlands in South Africa are rare and fulfil important ecological functions but are threatened by degradation. Because of this peatlands have gained increasing attention from scientists during the last two decades. However, knowledge of the peatland substrates and the means to classify them is limited. This study was conducted in peatlands of the Maputaland Coastal Plain. The approach uses the German Soil Mapping directive ‘KA5’, which acknowledges the accumulation process of substrates and botanical peat types. The aims were to investigate which substrates occur, whether these have affinities to certain hydrogeomorphic wetland types (HGMTs), and to determine the physical and chemical properties. Seven peatlands in five different HGMTs were investigated along 19 transects with 141 soil profiles and 674 horizons. In total 15 different peatland substrates were encountered and characterised, amongst them raphia peat, ficus peat and peat-gyttja, which have not been described previously. Mean values were determined for organic matter content, bulk density, degree of decomposition, porosity, pH and carbon/nitrogen ratio. A substrate reference scheme was also developed and classifies the encountered substrates with respect to their occurrence in HGMTs.</p>