A STEP in the right direction: Updating the Thicket Biome for the National Vegetation Map 2017

Abstract

The National Vegetation Map of South Africa (VEGMAP) has been updated on two previous occasions to improve the representation of ecosystems in the map. The third and latest update of the VEGMAP coincides with the 2018 National Biodiversity Assessment (NBA), and a key focus of this update is a refinement of vegetation types of the Thicket Biome. To achieve this, a modification of the Subtropical Thicket Ecosystem Project (STEP) vegetation map was used in a collaborative effort between the South African National Biodiversity Institute, Nelson Mandela University, and thicket experts who developed STEP. The focus of this phase of the project was to review all solid thicket STEP vegetation types that could be integrated into the VEGMAP. During this process many STEP types were merged, and portions were split to form a revised configuration of types. This update of the Thicket Biome incorporates 3% of the total VEGMAP area, while the Thicket Biome now contributes 10% (43 types) of the number of types in the VEGMAP compared to 3% (14 types) in 2012. The Thicket Biome map no longer has types stretching across multiple soil and climate gradients, and it is likely a better representation of vegetation for this biome. These refinements will therefore improve decision-making in this bioregion and the updated map will be used in the 2018 NBA assessment.