Format: ORAL

Colin T. Kelleher1,*, Samuel Belton1 and Philippe Cubry1, 2

1 National Botanic Gardens of Ireland, Dublin, Ireland 2 Université de Montpellier, CIRAD, IRD, Montpellier, France

Over the past 20 years our understanding of Irelands tree flora has increased significantly through genetic analysis. While Ireland has among the lowest native forest cover in Europe along with considerable recent planting, the remnants do show a signature of a native flora rather than that of an introduced flora. What emerges from the evidence is a relatively depauperate genetic component, a subset of Europe with reduced genetic diversity. This is to be expected from an island on the western periphery of the distribution of many European trees. We review studies completed to date in Alder, Ash, Birch, Oak and Scots pine. We show that while each species is unique, two overall patterns have emerged. One for species with temperate distributions showing a link with the Iberian Peninsula refugium and another for more cold tolerant and boreal species which shows a mix of Iberian genotypes along with those from a more northerly refugia. This baseline data is essential for situating Irelands tree flora in a European context. However, many questions remain, such as the sequence and dynamics of invasions through chloroplast capture and the contractions and expansions of populations over time. Further work is ongoing to improve our understanding of the genetic landscape of the native tree flora.