Revision of the North West province vegetation map

Abstract

Background: The vegetation type boundaries in the North West province as they appear in the 2018 National Vegetation Map, for the most part, are derived from agricultural land types that were mapped in the 1980s. Aim & objectives: Given (1) the importance the National Vegetation Map plays in conservation assessment and planning, as well as environmental planning and decision making; and (2) the map boundary errors reported by users, an update of the provincial vegetation map was considered necessary. Methods: A vegetation identification key using high-level environmental parameters (in order of importance: flooding, bioregion, terrain, geology and soil) was developed. This key was used to manually interpret high-resolution colour aerial imagery, together with existing environmental spatial datasets (land types as a proxy for soils, simplified geology and terrain/land form). The existing vegetation type concepts are sound and are mostly retained in this map. Results & conclusion: Changes to the map include: (1) all vegetation boundaries in the province are remapped; (2) Olea Sclerophyllous Forest is proposed as a sub type/community related to the Northern Afrotemperate Forest vegetation type; (3) two existing vegetation types currently not mapped as occurring in the province are brought into the province, namely, Subtropical Alluvial Vegetation and Waterberg Mountain Bushveld; and (4) three vegetation units recognised in previous vegetation studies and which are not indicated in the current National Vegetation Map are included here as new vegetation types, namely, Vryburg Thornveld, Morokweng Thornveld and Central Sandy Mountain Bushveld. The descriptions of all terrestrial vegetation types occurring in the province are also updated and an updated annotated global plant species list for the province is provided. Changes reflected in this vegetation map have been incorporated into the National Vegetation Map Version 2024 beta.