A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2015. / Mountains are one of the most important and yet environmentally sensitive habitats in the world, they act as reservoirs of species, and have frequently served as refugia for organisms during periods of climate change and provided subsequent sources for speciation. As temperatures increase due to global climate change, species are shifting to higher altitudes to escape the effects of warming at lower altitudes. The spatial distribution and diversity of alpine vegetation is strongly influenced by environmental factors such as snow cover, solar radiation, soil moisture, humidity, and air/ground temperature. Snow cover is one of the most important factors controlling ground level microclimate and alpine plant growth. My study was undertaken near Kotisephola Pass at ca. 3300 m.a.s.l. in eastern Lesotho. Three zones were identified namely, upper, middle and lower zones at the site, as a result of vegetation differences that were observed along a 30 m transect from the rock scarp to the tussock grasses. The environmental variables of temperature, soil moisture, solar radiation, snow depth and humidity were measured over a period of 17 months using i-Buttons, Hobo and Tinytag data loggers, probes, solar radiation and temperature data loggers. Vegetation sampling was undertaken to determine aerial cover, and species composition, richness and diversity during the summer growing season of January and February 2013. The study site portrays strong fine-scale botanical micro-zonation owing to ground level microclimatic differentiation as a consequence of topographic (i.e rock scarp) shading and snow capture. Temperatures were >5 °C warmer in the upper zone from July – September 2012 due to the deep (1 m) snow cover which lasted for two months longer than in the middle zone, and only lasted for 36 hours in the lower zone. Accordingly, the upper zone had the lowest solar radiation throughout the data collection period due to the continuous snow cover and shading from the rock scarp. Three botanical zones were identified as characterised by different Helichrysum species. The upper zone (21 species) was more species rich than the the middle (19) and lower (18) zones. The vegetation is dominated by grasses which cover >35% of the study site, whilst herbs and shrubs cover only ca. 6% with an average of 12.3% bare ground. The strong zonation in plant species composition is a response to the fine spatial-scale changes in the environment, resulting from snow cover acting in ameliorating the harsh iii alpine conditions in winter. More detailed research on a larger scale is still required to fully comprehend phenology and morphology of the plants at the study region.