Abstract
M.Sc.
Mabula Game Reserve initiated an extensive grass-monitoring programme ten years ago. At the same time, management kept records of factors such as rainfall, burning, game numbers and game composition that might have an influence on grass production. They also conducted an extensive mapping programme over a number of years to familiarise themselves with the physical phenomena of Mabula, namely geology, soils, slope and aspect, that influence grass growth. The most important aspect of their mapping programme was to divide the reserve into different vegetation communities.
The objective of the study is to supply Mabula Game Reserve with clear-cut evidence of the condition of the grazing resources at Mabula. The aim of the study is to assist the management of Mabula with future guidelines in the veld management of the reserve.
The overall purpose of this study was to investigate the veld management efficiency of Mabula Game Reserve by establishing whether the ecological status of the grazing had been degraded or improved over the study period. This researcher analysed the grass monitoring data to determine veld condition indices, grazing values, perenniality and to establish the amount of climax and pioneer grass. He sequenced his research by:
• classifying grass species in terms of the ecological index method to determine whether grass had been utilised in a sustainable manner or over-utilised;.
• calculating the grazing capacity for each vegetation community over the past ten years;
• highlighting those grass species in the analyses that showed abnormal growth or decline over the ten years; and
• interpreting the results in terms of the ecological status of the relevant area..
The study was conducted firstly by categorising the grass monitoring stations into different vegetation communities. Ecological indices for each vegetation community was determined. The grass species that showed the biggest increase/decrease in the ten years of monitoring were seperated to determine the ecological significance of the increase/decrease. The ecoloical indices of the different vegetation communities were compared with each other to determine the overall improvement or deterioration of the veld quality.
By re-calculating the game numbers for every year, this researcher was able to determine the Game Livestock Unit for the area. With this figure, he was able to differentiate between the grass utilisers, comparing them from year to year in terms of their grazing capacity.
The study revealed that in order to obtain an objective view of the condition of the veld, it is necessary to evaluate the condition of the veld in terms of each vegetation community, as well as the total area. Such an approach would enable the manager to plan according to a specific vegetation community. The study also made it clear that it is necessary to reduce the number of game, but that this must be done by culling the appropriate group of utilisers. The necessity of introducing a browsing monitoring programme soon became evident.
The study showed how the grass and game monitoring analyses for the area can be applied in association with the rainfall figures in forward planning in order to manage the sustainable utilisation of biological resources and to minimise the effects of drought conditions.
The researcher concluded this study by highlighting the shortfalls of the ecological index method in determining the condition of the veld, and recommended other methods i.e. the Benchmark Method, Key Species Method, and the Weighted Key Species Method to supplement the present method. Another recommendation was to collect two different sets of data during monitoring to avoid conflicting results, as was the case with the 2004 survey. One data set should include herbs and forbs while the other set should only contain grass species.