Ekologiese skeiding tussen groot herbivore van die Messina-proefplaas, Limpopovallei

Abstract

Herbivore-habitat relationships were studied on the Messina Experimental Farm. A phytosociological classification of the vegetation was done and the plant communities were mapped and described. The plant communities were quantitatively described in terms of veld condition score, standing crop and leaf phenology of the woody vegetation. Observations were made on the occurrence, distribution and density of Burchell' s zebra, blue wildebeest, eland, giraffe, gemsbok, impala, kudu and warthog in the different plant communities. The frequency of ungulate observations differed significantly for 14 of the 20 environmental parameters that were noted at each observation point (P < 0.05). The ungulates displayed a higher degree of overlap in plant community preferences in the wet season than in the dry season. This indicated that the ungulates were more selective when resources were limited. Preferences for plant communities, seasonal variations in these preferences and selection for specific environmental parameters, contributed to different levels of ecological separation of large herbivores on the Messina Experimental Farm. Coefficients of competition, based on indices of overlap in habitat and diet selection, were calculated for the different ungulates. These coefficients were used to calculate replacement values in terms of livestock units and browser units. It is proposed that these replacement values be used to calculate stocking rates for game ranches in the Mopani veld.