Vegetation monitoring, recording the recovery or change in plant cover over time, for several Karoo shrubs was undertaken to evaluate the Savory Grazing System on a farm in the Succulent Karoo. This evaluation was quantified by establishing if the proposed 120- day rest period between grazing events was sufficiently long enough for complete recovery of the vegetation. Complete recovery was described as sufficient regrowth after a grazing event so that continual cover loss would not result over time. Optimum resting periods would ensure that cover loss, due to grazing, could be recovered so that plant size and reproductive potential was not detrimentally affected. The ellipse intercept method was used to sample piospheres (or zones of attenuating animal impact) around water points in two vegetation types. From these results, 320 line transects for vegetation monitoring were located between 140 and 180m from the water points. One and a half year old piospheres of one farm were compared to seventeen year old piospheres on another farm with similar vegetation composition. The piospheres on the younger farm were expanding at an approximate linear rate of 80m per year, however, this rate slows considerably, as was found on the farm with older piospheres. Stability or equilibrium appears to be reached at approximately 320m from the water point in the older system. The line transects were used to record the change in cover of palatable and unpalatable Karoo shrubs on a monthly basis over an 18 month period. In all instances it was concluded that the proposed 120-day rest period was not sufficiently long enough for complete recovery of the vegetation. The highly palatable species, especially Osteospermum sinuatum and Tetragonia spp., were the most heavily utilized and detrimentally affected. Larger individuals of the palatable shrubs O. sinuatum and Tetragonia spp. were more severely grazed than smaller individuals as a result of smaller individuals utilising spiny nurse plants under which to establish. If the present rest period is continued the result could be overgrazing and local extinction of these important fodder species. The responses of two highly palatable species, O. sinuatum and Tetragonia spp., were monitored closely in relation to rainfall and grazing events. Grazed and ungrazed (protected) individuals were monitored over one year to substantiate the results obtained from the line transects. The rest period was again found to be too short for full recovery and was also found to be reducing the reproductive output of O. sinuatum and Tetragonia spp.. The recruitment of O. sinuatum and Tetragonia spp. was also measured by comparing seedling establishment in grazed, ungrazed (vegetation protected from sheep grazing) and cleared vegetation. In an attempt to rehabilitate these rangelands, Pteronia pallens, a dominant unpalatable shrub, was cleared and the resultant seedling recruitment of O. sinuatum and Tetragonia spp. monitored and compared to grazed and ungrazed vegetation. Juvenile recruitment of these species was found to be significantly lower in the grazed than in the ungrazed vegetation. Recruitment of Tetragonia spp. was found to be significantly higher in the cleared strip compared to the grazed and ungrazed vegetation. The results obtained in this study suggest that the present grazing regime is having a detrimental effect on the vegetation and that revised management procedures are needed to ensure the conservation of these rangelands. The rest periods between grazing events need to be lengthened as well as a reduction in stock numbers. Certain camps need to be skipped on a seasonal basis during the flowering season in order to increase the reproductive output of highly palatable species. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1995.

A grazing trial investigating the effect of season of grazing and stocking rate initiated at the Nortier Experimental Farm in 1988 provided an opportunity to assess the response of the veld to both grazing and environmental influences in an arid environment. The trial allowed an assessment of the relative influence of internal (equilibrium) and external (non-equilibrium) forces on the dynamics of an arid rangeland. This study involved the analysis of a nine year data set stretching from 1988 to 1996 and served to provide evidence supporting the existence of an equilibrium/non-equilibrium continuum in rangeland dynamics. The most significant implication of this result is that rangeland systems should not be classified as either equilibrial or non-equilibrial, but rather according to a continuum extending between equilibrium and non-equilibrium poles. The exact position of any system on this continuum is a function of the relative influence of internal and external forces on its species dynamics. The dynamics of the veld at the Nortier Experimental Farm showed significant response to both grazing and environmental variables suggesting conformity to both equilibrial and non-equilibrial paradigms. Both ordination and analysis of variance highlighted the importance of rainfall particularly in the fluctuations of the predominant grass species, Ehrharta calycina, which increased in abundance with rainfall. Partial ordination enabled the assessment of species variation following the removal of variation associated with rainfalL Partial ordinations revealed the gradual, directional movement of samples through multivariate space in response to grazing treatments. Individual plant species were also shown to be responding to grazing, the extent of which was influenced by season of grazing and stocking rate. Both the partial ordinations and the ANOVA showed Melothria sp., Tetragonia fruiticosa and Hermannia scordifolia as increasing and Ruschia caroli as decreasing in absolute abundance in response to grazing. Season of grazing was shown to significantly influence the abundance of H. scordifolia over time. The 'shrublherb complex', which constitutes the 'key resource' at the Nortier Experimental Farm displayed an increase in absolute abundance over the duration of the trial. This increase in absolute abundance was accompanied by an increase in the relative abundance of the palatable component of this resource. The application of medium to heavy stocking rates during spring, summer and autumn and low stocking rates during winter resulted in elevated absolute abundances of palatable plants. Furthermore, low stocking rates, when averaged across all season of grazing treatments, resulted in a significantly higher absolute abundance of unpalatable plants. These findings provide the basis for the development of management principles for the Strandveld Vegetation Type. The application of medium to heavy stocking rates within a rotational grazing system, as recommended by the literature dealing with grazing systems in the Karoo, is supported by the results of the Nortier grazing trial. Medium to heavy stocking rates should be applied during spring, summer and autumn and low stocking rates during the winter months. Furthermore, it is recommended that rests of between 12 and 14 months should be afforded to portions of the veld periodically due to the variability in growth, flowering and fruiting times ofdifferent plants in the Karoo. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.