Figure 1.

Inputs and losses of biological diversity in the Anthropocene, from a regional perspective (the region can be small or large). The schema is illustrative rather than exhaustive. The larger ‘arrival’ than ‘departure’ arrows reflect that regional diversity (number of species per country or island) has increased for most parts of the world, over the last 300 years. Humans affect changes taking place within each region, the arrival of new species and the losses of ones that die out. The questions (bottom of figure) relate to what our targets should be for any regions when systems are dynamic (centre); who, why and how we should decide to import additional species deliberately (left); and why and how we might try to retain species for which the region is no longer suitable for their survival (right).