Dispersal of moss propagules on Signy Island, maritime Antarctic

Aerobiological studies were conducted for >1 year using arrays of rotorod samplers at three sites on Signy Island, South Orkney Islands, maritime Antarctic. Spores of five bryophyte taxa were identified, all of which are known to be widely distributed and fruit frequently on the island. Spore size did not appear to influence potential for dispersal, with spores of all five taxa being captured 0.5-1 km from their nearest known source plants. Spores were more abundant than plant fragments, although the occurrence of both propagule types in the air was small in comparison to the ground cover of mosses, and the occurrence of lichen propagules in the air. Spores were captured over a much longer period of the year (including the winter months) than that in which sporophyte dehiscence is thought to occur on Signy Island; possible reasons for this are discussed.