The origin of recent biological invasions in sub-Antarctic islands: the case of Poa annua

Abstract

The Southern Ocean presents one of the most interesting arenas in which to study phylogeographic patterns linked to dispersal and the drivers of propagules. This area stands in stark contrast to the Arctic circle in the northern hemisphere, given the very different land to water ratios present in these two polar regions ,highlighting the huge distances and small areas between the sub-Antarctic islands. The remoteness of these areas has allowed them to remain as one of the most pristine areas of the planet, only disturbed by first explorers and scientific expeditions. However, increase in visits together with climate change, has increased the probability of biological invasions, making the region an ideal scenario to study their recent impact. A prime example of successful coloniser has been Poa annua. This herb is arguably the most successful invasive plant in the Southern Ocean, having colonized recently several sub-Antarctic islands. We have developed microsatellite markers with the intention of unravelling its phylogeographic structure and spatial dynamics. This will give new insights about the patterns of connectivity-isolation between islands, as well as introduction routes, the sources of new invasions, and how to reduce the risk of human introductions. - Abstract as displayed in the - Abstract booklet. The presentation on the day may differ from the - Abstract.