Abstract
This project addresses the occurrence of long-distance dispersal in ferns by studies at different temporal, spatial, and phylogenetic scales. First, I will test if disjunct fern distributions that span isolating barriers are a consequence of ferns' ability to easily disperse over long distances, or, if the distributions are historical remnants reflecting vicariance events. Studies include for example pantropical taxa with a Mesozoic origin, i.e., groups with the potential of showing vicariance patterns as a result of the breakup of Gondwana. Second, I will at the intraspecific level test if phylogeographical patterns are discernable, i.e., reconstruct dispersal patterns by analysing how populations are related to each other, and their geographic distributions. Third, I will test if ferns are limited by dispersal by conducting spore sowing experiments. I will use tree ferns (Cyatheaceae and relatives) and cliff ferns (Woodsia, Woodsiaceae) as model organisms. The overwhelming majority of plant biogeography studies have hitherto focussed on seed plants. By comparison, few have targeted the sister group to seed plants, the ferns. Our understanding of the impact of long-distance dispersal in ferns will have implications in a conservation perspective. In a fragmented landscape the potential for successful recruitment after long-distance dispersal determine the relative vulnerability of ferns to climate change.
Sweden