Article

The seed bank of arable fields is the major source for the renewal of weed species. Three field studies were carried out from Ocotober 2000 to July 2001 in autumn wheat (Triticum durum) and lupin crops (Lupinus albus 'MISAK') al Queluz (near Lisbon) and in an autmin wheat (Triticum durum) in Alqueva (Alentejo). The methodology applied was that of the European Weed Rescarch Society (EWRS) ex - Working Group "Biology and Ecology or Weeds-seedbanks and Real Flora 01" Agricultura l Land", The seedling emergcence from the soil samples (seedbank) was recorded weekly taking into account the Mediterranean species. The common dominant species in Queluz were Anagallis arvensis, Euphorbia peplus, Legousia speculum-veneris, Papaver rhoeas, Polycarpum tetraphyllum and Polygonum aviculare, and in the Alqueva Cichorium intybus, Sinapis arvensis, Sonchus oleraceus and Trifolium isthmocarpum. Knowledge of seeding emergence during the year is an important aspect for thc conservation of Mediterranean specics like Legousia speculum-veneris, that nowdays occurs only in Central-Western Lisbon region. The Queluz field study will be continued until 2002.