of the Phase Three situation. In fact, Phase Four would probably require artificial veld reclamation measures. The destruction of Phase Four vegetation the development of Phase Five appears to be a final stage; this is where vegetation is practically entirely destroyed and the soil completely exposed to erosive agents.
It must be borne in mind that the concept of vegetation change as set out above has bearing on the general situation in the Karoo Region. At any particular locality, depending on its grazing history and climate – especially average rainfall - the various phases may vary in duration and intensity and may overlap and merge considerably or may even be indistinguishable. The various phases should never be considered as distinct or discrete stages.
In the marginal grassveld regions the Phase One situation rapidly develops into Phase Three. Phase Two is usually of relatively short duration and is usually not severe. Also, as a result of the higher potential of grassveld areas there are far greater prospects of the reversal or halting of phases here than in arid areas, excluding possibly that of the western arid grasslands (Bushmangrassveld). It should be pointed out here that there are still vast tracts of veld - especially in the eastern dry grassveld and adjoining grassveld which are in the late stages of Phase One.
The ecological unravelling of these phase changes and those taking place within phases, afford some of the most demanding and complicated studies that can be undertaken by the plant ecological and pasture sciences. The identification of the phases as set out above can afford the basis for developing new philosophies and new approaches to the reclamation of vegetation.
It should be pointed out here that the geographical distribution of insects, birds, mammals and reptiles are also affected by the development of the phases.
In the Karoo Region there are deserts, semi-deserts and arid lands, such as they have been over the centuries. It cannot be disregarded that there is desert encroachment and there is climatic change. However, currently these processes are negligible as compared to the alteration of degradation of the vegetation under grazing by domestic animals. Grazing by stock is today the most active and overriding ecological factor operating in the South African grazing lands. It can, however, operate for better or for worse.
In the years that lie ahead the Karoo farmer will have to face the problem of vegetation utilization as well as reclamation. However, utilization and reclamation are well within reach as the numerous and excellent examples of veld reclamation show. In order to substitute for loss of grazing capacity and to decrease grazing pressure on the veld without forfeiting economy, it is imperative that additional sources of stock feed be created on the greater majority of farms. In this respect it is inevitable that in the nineteen-eighties the establishment of plantations of drought hardy fodder species and fodder reserves will gain new status and impetus. Such resources, coupled with sound veld and stock management, spells good for the future of extensive stock farming in the arid region of South Africa. There is every reason to believe in the economic success of extensive small stock farming.
Karoo Agric 1 (5), 15-16