Scale and conservation planning in the real world

Conservation planning is carried out on a variety of geopolitical and bioge ographical scales. Whereas considerable consensus is emerging about the mos t appropriate procedures for identifying conservation areas, the spatial im plications of conducting conservation planning at divergent scales have rec eived little attention. Here we explore the consequences of planning at dif ferent geopolitical scales, using a database of the mammalian fauna from th e Northern Provinces of South Africa. The conservation network resulting fr om treating the region as one unit is compared with networks generated sepa rately for the provinces nested in that region. These outcomes are evaluate d in ter ms of (i) their land use efficiencies, (ii) their spatial overlap, and (iii) the impact of algorithm attributes. Although land use efficienci es are greater on broader scales, on average the spatial congruence between the broad-scale regional network and fine-scale provincial networks was <1 4%. Algorithms using different selection rules fail to improve this disturb ing outcome. Consequently, scale has an overwhelming influence on areas ide ntified as conservation networks in geopolitical units. This should be reco gnized in conservation planning.