Historical frequency of wind dispersal events and role of topography in the dispersal of anostracan cysts in a semi-arid environment

摘要: Propagules of several freshwater invertebrates are passively dispersed by wind, but the importance wind as a dispersal vector remains poorly understood. We examined historical frequency events in cysts Artemia franciscana. A threshold speed ~5 km/h was required to begin dispersing surface-resting cysts, beyond which cyst increased rapidly with increasing speed. The analysis and data from our field experiment for last 45 years nearby airport revealed that strong enough disperse most at wind-exposed site common, occurring on ~16 snow-free days per year consistently over long time periods. In topographically uneven landscape, however, speeds vary substantially one location another; exposed were 69% higher than wind-sheltered depression. Accordingly, winds this sheltered occurred only 5 period. Cysts thus less likely from, more settle in, depressions areas. Sheltered areas could function traps wind-dispersing propagules.