Common invasive weed species in the central and south western rangelands of Uganda

Abstract

A study was conducted in the central and southwestern rangelands of Uganda covering the districts of Kiboga, Nakasongola, Nakaseke, Kyankwanzi, Masindi, Isingiro, Mbarara, Sembabule and Kiruhura, to identify the key invasive weed species that pose a threat to pasture and livestock production in the rangelands. Sampling points were established in five farms per district. The selected farms had relatively similar pasture and grazing management conditions (paddock grazing, continuous grazing and rested areas) which were then stratified in valley, slope, hill tops and improved pastures. A Modified-Whittaker sampling plot was used to collect the herbaceous vegetation, which was sorted, identified and counted to compute species diversity (richness and evenness), species dominance and similarity. A total of 33 herbaceous species were identified, with seven species being invasive (Sida rhombifolia, Urena lobata, Lantana camara, Mimosa pudica, Elephantopus scaber, Rivina humilis and Leonotis nepetifolia) and two common weeds (Amaranthus and Solanum incanum). There was high species diversity in all sampling areas, which is reflective of lack of concerted efforts in pasture production, but also an adaptive strategy to the precarious climatic conditions in the rangelands especially under low input production systems. Strategies should be made to establish drought tolerant and nutritious pastures; including designing and implementation of ecologically sound invasive weed control measures.