Temporal dynamics of areas of endemism under climate change: a case study of Mexican Bursera (Burseraceae)

Aim Our aim was to analyse the temporal dynamics of areas of endemism of Bursera species (Burseraceae), a dominant element of the Mexican tropical dry forest, between the Last Glacial Maximum (LGM) and the present day. We aimed to identify stable core sectors that have held permanent populations of endemic species. Location Mexican dry forest. Methods We modelled the geographical distributions of 81 species of Bursera and identified their areas of endemism at the LGM and at present. For each area of endemism, changes in time, species composition and distribution were analysed, and a spatially explicit temporal hypothesis was formulated. Results Three areas of endemism supported by geographically congruent elements were identified: the Central Mexican Pacific Coast, Western Balsas, and Eastern Balsas–Tehuacán/Cuicatlán–Tehuantepec. Within them we identified stable core sectors (refugia). Main conclusions The areas of endemism identified represent distinct evolutionary biotic components of the Mexican dry forest. Their stable core sectors may facilitate phylogeographical predictions at the level of species or species assemblages. The framework adopted allows us to formulate spatially explicit temporal hypotheses about biotic processes, based exclusively on geographical data.