Influence of scale on conservation priority setting – a test on African mammals

Abstract

Broad-scale priority regions for conservation can be identified usingdatabases on species distribution through the application of site-selectionalgorithms. However, the influence of scale on large-scale priority setting isstill unclear. Using a data set of all 939 sub-Saharan mammal species,we wanted to know if continental conservation priorities derived at the scales of 1°, 2°,4° and 8° latitude–longitude grid cells are consistent. We testedwhether (1) geographical location of minimum sets were nested across scale, (2)the selection sequence (priority) of areas within a minimum set were scaledependent, and (3) these coarse-scale priorities can act as a cost-effectiveshortcut for the identification of fine-scale priorities. We found that minimumsets at smaller scales were largely represented within minimum sets at largerscales, especially when flexibility was considered. However, the geographicallocation of the grid cells with highest priority in the minimum sets was onlyscale independent if ranked by number of endangered species, total speciesrichness or rare quartile species richness, but surprisingly not bycomplementary species richness. Minimum sets at a 1° scale were generallyidentified within the areas of the 2°, 4° and 8° minimum sets.Therefore, coarse-scale priorities may provide a pragmatic basis for immediateassessment of priorities for conservation.