Picking up the pieces: a biosphere reserve framework for a fragmented landscape - The Coastal Lowlands of the Western Cape, South Africa

The coastal lowlands of the Western Cape (CLWC) form part of the fynbos bio me, an area renowned for its high levels of plant diversity and endemism. T he vegetation of the CLWC has been severely reduced and fragmented, and is currently impacted on by agricultural, pastoral, coastal resort and urban d evelopment, as well as alien plant spread. Furthermore, most of the vegetat ion communities are under-represented within existing protected areas. In r esponse to this urgent need for increased conservation efforts, an initiati ve to establish a UNESCO-MAB biosphere reserve in the area has been launche d. The aim of this project was to use biological criteria to identify areas that could potentially contain the core areas and buffer zones of a biosph ere reserve. A reserve selection algorithm was chosen which provides a flex ible tool for selecting representative areas for protection. The algorithm is a step-wise heuristic, which has rules for including mandatory polygons, forcing adjacency, including desirable (e.g. Red Data Book plant species) and excluding undesirable features (e.g. bisection by major roads). Farm bo undaries (cadastral units) were used as selection units, resulting in a tot al of 1717 parcels. The selection process was conducted three times with ta rget areas set at 10%, 25% and 50% of the original extent of each vegetatio n type within the study area. Areas of 62 834 ha, 121 199 ha and 242 397 ha , respectively, or 36% 49% and 76% of the available land in the study area being selected. It is recommended that the area identified as the 50% targe t area be considered the future site of core areas and buffer zones for the proposed biosphere reserve. The algorithm successfully maintained a high d egree of connectivity between selected areas. This is important considering the high levels of plant beta diversity associated with edaphic gradients. Rather than presenting a definitive reserve system, this study provides a tool allowing biological criteria to be included explicitly within the nego tiation process. As the biosphere reserve is assembled, priorities can be r e-assessed.