XVI International Botanical Congess

The present geographic structure of chloroplast DNA diversity of European deciduous oaks was largely established at the outset of postglacial recolonization. Founding events through long-distance colonization events by acorns then produced a patchy structure, with large areas fixed for a single haplotype. However, fragmentation of the forests and the high turn-over of wooded and agriculture land since the Neolithic period in Europe, as well as more recent artificial plantations, are starting to blur this natural pattern. Some artificial seed transfers have taken place during this century. They can now be identified by comparison with reference maps obtained by studying native oak populations. The adaptation of the exotic provenances can therefore be compared with the local ones.