High-altitude wetland vegetation of Bokong Nature Reserve in Matšeng Biosphere Reserve, Lesotho

Bokong Nature Reserve (BNR) forms part of the core of the first and newly established Matšeng Biosphere Reserve in Lesotho. However, lack of baseline data makes it difficult to monitor the wetland vegetation in BNR. This study characterised the vegetation of the high-altitude montane palustrine wetlands of this area. Plant species composition was assessed using the Braun-Blanquet approach, and the height and cover of the vegetation were measured. Furthermore, environmental data were collected using standard methods. The data were analysed by determining species richness and calculating Shannon-Wiener diversity and evenness, as well as employing cluster analysis, canonical correspondence analysis and redundancy analysis. The results show that a total of 175 plant species from 102 genera and 40 families were encountered. The dominant plant families were Asteraceae, Poaceae and Cyperaceae. Hierarchical cluster analysis produced 10 plant communities in the range of 1–36 species per 3 m × 3 m plot. Important environmental factors influencing the wetland vegetation were longitude, altitude, latitude, soil sodium, inundation, soil texture, soil magnesium and soil phosphorus. The results indicate that the wetlands are not only in a relatively stable condition, but also support diverse vegetation and store a substantial amount of carbon, thus contributing to biodiversity conservation and climate change mitigation. Because the wetland vegetation determines the functioning of the system, which in turn influences the supply of ecosystem services, our findings form a baseline dataset for monitoring the BNR wetland vegetation, especially in the face of climate change. Conservation implications: The BNR wetlands fall within the catchment of the Lesotho Highlands Water Project dams that are important for water resources in southern Africa. Furthermore, the wetlands are of international conservation value because they form part of the core of a UNESCO-declared man and biosphere reserve and play an important role in supporting biodiversity.