The effect of Avena sterilis L. invasion on weed abundance and diversity in conventional and organic cereal fields in the Mediterranean region

Summary

The aim of this paper is to analyse the growth of the native invader weed Avena sterilis L. (wild oat) and its invasion effect on weed community abundance and diversity in relation to cropping system (organic vs. conventional) in dryland cereal fields under Mediterranean conditions. To achieve this, a comparative experimental design involving one conventional and one nearby organic field was used. Our results show that the effect of A. sterilis invasion on resident weeds and cereal biomass depended on the cropping system. Species richness and diversity of weed community were more negatively affected by the invasion in the conventional field, whereas cereal biomass was drastically reduced in the organic field. The cropping system did not affect the invasive ability of A. sterilis, but the higher A. sterilis biomass recorded in the conventional field suggests strong potential long-term invasions in this system.