SEED SURVIVAL AND PERSISTENCE ON A CALCAREOUS LAND-SURFACE AFTER A 32-YEAR BURIAL

Of 34 species of vascular plants recorded in an unimproved calcareous grassland community in 1960 and subsequently buried far 32 yr, just si x spp. were recovered as viable seeds from the original land surface, following excavation of an experimental earthwork. Five of the six are known or suspected to form persistent seed banks; the status of Carex flacca as a persistent seed is now established. The exceptionally low density of viable seeds at 35 seeds/m(2) and the paucity of other pla nt remains confirm that these calcareous soils have supported rapid de composition. The complete absence of viable seeds known to be short-li ved indicated that the macrofauna has played no significant role in th e introduction of viable seeds from the modern-day surface down to dep ths in excess of 1.6 m, at least not in recent years. Because of the p recise dates of burial and excavation, the results offer a rare opport unity to confirm laboratory and other indirect observations of long-te rm seed persistence following burial in temperate climate calcareous s oils.