LINKING RIPARIAN VEGETATION TYPES AND FLUVIAL GEOMORPHOLOGY ALONG THESABIE RIVER WITHIN THE KRUGER-NATIONAL-PARK, SOUTH-AFRICA

Vegetation types were studied in relation to the fluvial geomorphology along the mixed bedrock-alluvial Sabie River within the Kruger Nation al Park, Mpumalanga, South Africa. Six vegetation types were identifie d using TWINSPAN analysis, namely: Phragmites mauritianus, Phyllanthus reticulatus, Breonadia salicina, Combretum erythrophyllum, Diospyros mespiliformis and Spirostachys africana vegetation types. Spirostachys africana and Diospyros mespiliformis vegetation types were found to o ccur predominantly on the stable, infrequently flooded macro-channel b anks, while the remaining four vegetation types were found almost excl usively along the more geomorphically and hydrogically dynamic macro-c hannel floor. The degree of bedrock or alluvial influence was identifi ed as being an integral factor in the distribution of the four macro-c hannel floor vegetation types at both the morphological unit and the c hannel type scale. The geomorphological continuum from the bedrock inf luenced bedrock anastomosing channel types, to mixed anastomosing and pool-rapid channel types, to the fully alluvial braided channel types, is reflected in the change in species composition from Breonadia sali cina vegetation type, to Phyllanthus reticulatus and Phragmites amurit ianus vegetation types, to Combretum erythrophyllum vegetation types, respectively. Given the vegetation/alluvial geomorphology links establ ished, changes in vegetation composition are proposed in response to s cenarios of geomorphological change as a result of a progressive sedim entation.