Contribution of the soil seed bank to post-fire recovery of a heathland

The importance of a soil seed bank was evaluated through its role in the re covery of a burnt shrubland. The study was carried out in a heathland chara cterized by several ericaceous species. Part of the heathland was burnt in a wildfire on 7 April 1991, while the rest was not affected by the fire and used as a control. Soil samples were collected three days after the wildfi re, in the absence of rain; 10 samples (20x25 cm width to a depth of 5 cm) were collected from the burnt area and 10 from the control. Samples were se t out in a greenhouse where germinating seedlings were recorded, counted an d identified for 17 months. Observations were also carried out twice in the field for 14 months after the wildfire by examining two permanent transect s in the study area and recording all regenerating species. The results sho w a low correspondence between soil seed bank and aboveground vegetation: o nly 23% of the identified taxa appeared both in the bank and in the field o bservations. From these species 65% of them have dispersal types like autoc hory or barochory, that is they generally fall near the mother plant. In th e identified species as a whole, therophytes and hemicryptophytes dominate in comparison with chamaephytes, phanerophytes and geophytes; this also app lied to the herbaceous species in comparison with the woody ones. Potential ly soil possesses an important seed bank, which contributes poorly to the v egetation recovery after fire.