Quercus suber distribution revisited

Abstract

The complex evolutionary history of Quercus suber is still under debate. Also, data and evidence at the eastern end of the species range are largely incomplete. In this study, historic floras, fossil data, and local toponyms were surveyed and genetic analyses and linguistic research used in order to point towards a previously neglected occurrence of Q. suber east of Italy. Such a multidisciplinary approach depicts a scenario in which cork oak survived in the Balkan Peninsula until recently and suggests how Q. suber might have been evicted and relegated westward, due to climate changes, ecologic competition and human impact. Our findings also suggest that the differentiation core of Q. suber was in a yet unidentified area corresponding to present-day central Europe to southwestern Asia. Radiation occurred during the Middle Miocene, with a later extension into southern Europe, Iberia and North Africa, as documented by samples collected from the late Miocene-early Pliocene. The causes of extinction in the east, however, should be investigated further and may lead to investigations about other species that might have experienced range shifts similar to that of cork oak.