Possible role of the seed bank in the restoration of open sand grassland in old fields

The species composition of the seed bank and aboveground vegetation of an old field was compared to a reference grassland stand. The relative importance of dispersal and recruitment as limiting factors was analysed, and measures for appropriate restoration are proposed. Grassland species were able to re-establish in the old field soon after abandonment of cultivation, with Stipa borysthenica as the dominant species. Five years after abandonment of cultivation, the seed bank was still dominated by weedy annuals while grassland species made a relatively high contribution to the seed bank in the reference site. The results do not support recruitment to be the limiting factor in recently abandoned fields, because grassland species that occurred in the seed bank were also present in the vegetation. A rapid regeneration of the matrix species is predicted due to their good dispersal capacity and the vicinity of the open sand grassland. However, the introduction of subordinate species and the control of invasive plants might require human intervention.