Advancing coastal cross-realm integration for planning and assessment

Abstract

The coast is one of South Africa’s most valuable national assets but has been poorly included in biodiversity plans because the realm has been split into its “land” and “sea” components. Even if planners intended to include the coast meaningfully, this has been impossible because the terrestrial and marine ecosystem type maps don’t align along the shore. Thus, a key step in progressing cross-realm integration for both planning and assessment is to generate a fine-scale coastal ecosystem-type map that is seamless among realms. We explicitly avoided controversial boundaries, rather choosing the most stable boundaries available that divide the ecotone into ecologically meaningful zones. We defined and mapped (at <1:3000) the “seashore” as the land-sea interface between the dune scrub/thicket break and the back of the surf zone. The seashore is divided at the dune base into a landward “backshore” (which replaces the seashore vegetation type) and seaward “shore”. Given the dynamic nature of the coast, temporal aspects were included in the boundary delineation and ecosystem type classification, where appropriate. The estuary delineation from the National Biodiversity Assessment 2018 was also embedded in the map. South Africa is now the first country with a wall-to-wall ecosystem type map for its territory and Exclusive Economic Zone.