Vegetation and associated environmental conditions of the high-altitude Letšeng-la-Letsie Palustrine Wetland, a Ramsar site in Lesotho.
Lesotho has only one wetland designated as a Ramsar site, found at Letšeng-la-Letsie, which is located within the Maloti-Drakensberg region. Despite its designation as a wetland of international importance, little is known about its ecology and biodiversity. Information on wetland biodiversity is crucial for monitoring and conservation planning. This study investigated the vegetation-environment relationships in the Letšeng-la-Letsie Wetland, Lesotho. Vegetation and environmental data were collected using the Braun-Blanquet approach and standard methods, respectively. The data were analysed using cluster analysis and ordination techniques. The study recorded a total of 68 plant species from 50 genera and 23 families in the wetland, with Cotula paludosa, Eragrostis caesia, Haplocarpha nervosa and Trifolium burchellianum as some of the most dominant species. Three distinct plant communities were described: Potamogeton pusillus-Ficinia cinnamomea, Helichrysum glaciale-Eragrostis caesia and Cotula paludosa-Trifolium burchellianum. The communities and species richness recorded revealed high diversity in this wetland when compared to similar wetlands within the Maloti-Drakensberg region. Ordination revealed that species diversity and the plant communities are mainly influenced by altitude, inundation depth, mottling depth, longitude and various edaphic attributes (potassium, total organic carbon, sodium and cation exchange capacity). This study provides the baseline information, which is essential for planning, monitoring and managing this wetland of international importance. In addition, the presence of introduced invasive species suggests the need to practically protect this wetland by implementing the developed management strategies. This will ensure the conservation of biodiversity, sustainable ecosystem service delivery and compliance with the Ramsar Convention requirements.