Aspects of seed dispersal, particularly mobility of viable seeds, were investigated in two sites at the lower river Dalauml;lven, southeastern central Sweden, from 1980 to 1985. Three different approaches were used to assess the seed rain. (i) Seed traps were placed at ground level. This component of the seed rain was dominated by seeds from the local vegetation, particularlyBetulaspp. A total of 30 species were identified, (ii) Drift material was collected in spring and autumn and the seed content was identified through germination trials. Seeds dispersed by drift mainly belonged to species abundant in the study sites, but included a minor element not represented in the local vegetation. A total of 23 species were identified, of which seeds ofPotentilla palustris,Carex canescens, and otherCarexspp. were most abundant. In the field, seedlings growing on fresh accumulations of drift were dominated byPotentilla palustris. (iii) Samples of snow were collected and the seed content determined visually. Of the seven species represented in the snow samples,Betulaspp. dominated. In particular, flooding extended the seed rain beyond the boundaries of many species. It is concluded that the distribution of wet meadow species is not limited by dispersal.
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