Format: ORAL

Jennifer Clayton-Brown, Prof. Paul Ashton

Biosciences, Edge Hill University, Ormskirk, UK

Salt Marsh plants are specialists in a highly stressful, spatially restricted, though predictable environment. Dispersal, through pollen, seed or vegetative fragments will need to be efficient and possibly specialised to reach suitable habitats. Carex section Phacocystis (Cyperaceae) incorporates a group of wind pollinated long lived clonal species with an Amphi-Atlantic distribution which inhabit salt marshes. They thus present a suitable suite of species to investigate maritime dispersal methods. On the Norwegian coast three of the section; C. paleacea, C. salina and C. subspathacea occupy different niches on the salt marsh characterised by different distance from the low tide. C. subspathacea occupies the lowest position on the saltmarsh and is infrequently free of saltwater immersion while C. paleacea is only submerged at very high tides. C. salina is intermediate between the two. These species thus provide an opportunity to assess transport distances at small and medium scale along the Norwegian coast while the differing extent of offers an additional, potentially influencing, factor. The discovery of a C. salina population in Scotland in 2004, a species previously unknown in the UK, with other Scottish populations subsequently discovered, reveals that longer distance dispersal across the North Sea is also occurring. The recent spread of the species into the UK highlights the dynamic nature of the salt marshes, especially under climate change.  Using genetic data obtained from microsatellite variation, patterns of dispersal and connectivity are assessed in this group. The effects of latitude and position in the salt marsh are considered alongside the possible source and pattern of long-distance dispersal. Spread via sexual or vegetative route is also assessed.