Climate change, plant migration, and range collapse in a global biodiversity hotspot: the Banksia (Proteaceae)

Climate change has already altered global patterns of biodiversity by modifying the geographic distributions of species. Forecasts based on bioclimatic envelop modeling of distributions of species suggests greater impacts can be expected in the future, but such projections are contingent on assumptions regarding future climate and migration rates of species. Here, we present a first assessment of the potential impact of climate change on a global biodiversity hotspot in southwestern Western Australia. Across three representative scenarios of future climate change, we simulated migration of 100 Banksia (Proteaceae) species at a rate of 5 kmdecade1 and compared projected impacts with those under the commonly applied, but acknowledged as inadequate, assumptions of ‘full- ’ and ‘no-migration. ’ Across all climatemigration scenarios, 66 % of species were projected to decline, whereas only 6 % were projected to expand or remain stable. Between 5 % and 25 % of species were projected to suffer range losses of 100 % by 2080, depending mainly on climate scenario. Species losses were driven primarily by changes in current precipitation regimes, with the greatest losses of species projected to occur in