PLANT COLONIZATION - ARE WIND DISPERSED SEEDS REALLY DISPERSED BY BIRDS AT LARGER SPATIAL AND TEMPORAL SCALES

It is suggested that many plant species often thought of as wind dispe rsed may in fact be largely dispersed by animals, mostly birds, at lar ger spatial and temporal scales. This possibility is illustrated by us ing data bn Holocene tree migrations in Europe. It is suggested that e xploratory movements, often by young birds, may play an important role in such dispersal rather than the classic return migrations of birds. In the case of European trees there could have been active selection for rapid migrations occurring even in the glacial refugia sites in th e mountains of southern Europe. Plant migration rates, and hence the a bility to deal with climatic change, may have been lower before the ev olution of a diverse avifanua. It is suggested that for many 'wind dis persed' seeds the wind dispersal mechanism is adapted to local dispers al (over distances of a few canopy diameters) and larger scale dispers ion is due to birds.