The use of land facets as biodiversity surrogates during reserve selection at a local scale

Where species distribution data are inadequate reserve selection procedures have to rely on surrogate measures of biodiversity. The informativeness of land facets (the simplest units of a landscape with uniform slope, soils and hydrological conditions) as a local scale environmental surrogate was investigated in the Venetia-Limpopo Nature Reserve, South Africa. Multivariate analysis (MDS, ANOSIM) revealed that the land facets adequately represent distinct bird and dung beetle assemblages and are therefore useful surrogates. These land facets/assemblages were subsequently used as attributes in the following reserve selection procedures: (i) Percentage Area Representation (PAR-represent a nominated percentage area of each assemblage); (ii) Species-Assemblage Representation (SAR-represent each species within the smallest number of assemblages); (iii) Assemblage Diversity (AD-maximising diversity by first selecting areas containing most dissimilar assemblages). The influence of grid cell size, target representation percentages and an over-representation constraint on the efficiency of the algorithms were illustrated. The SAR procedure did not represent assemblages lacking distinguishing species and were thus more efficient in terms of total area selected. The AD procedure selected a slightly larger area than the PAR procedure, but was highly effective at rapidly increasing the diversity of the reserve network. (C) 1999 Elsevier Science Ltd. All rights reserved.