Abstract

Rangelands occupy about 40-50% of the land area on Earth and are a critical resource for sustainable livelihoods in communities that depend on them. The productivity of these ecosystems depends on several factors such as water and nutrient availability, rangeland management strategies and complex adaptation processes. In South Africa, rangelands have been severely affected by anthropogenic activities such as imbalanced utilization and neglect of proper management processes and physical factors particularly rainfall and temperature. A randomized block sampling technique based on the rangeland management regimes and three rainfall zones characteristic of the North West province was employed to harvest biomass. The collected material was used to quantify above ground biomass (AGB). Results showed that rainfall (R²=0.44) and temperature (R2=0.43) distribution had significant impact on AGB productivity. Significant differences were also detected among rangeland management regimes [F(2,177)=85.20; P<0.001] in terms of AGB productivity. High rainfall areas produced higher quantity AGB, while low productivity is associated with low rainfall areas. Private ranches produced the highest AGB quantity and the communal areas produced the lowest. Based on these findings we can conclude that environmental factors such as temperature and rainfall and rangeland management activities are the most important factors that determine rangeland productivity in the North West province, South Africa. The study recommends proper management systems to maximise rangelands productivity.

Keywords: Above ground biomass; Communal lands; Private ranches; Protected areas; Rangeland regimes; Rangelands