Weed species diversity and cover-abundance in organic and conventional winter cereal fields and 15 years ago

Summary in the original language of the document

In this research, we compared the weed species development in conventional and organic winter cereals in Upper Austria. The investigations were done in 2003 in 15 paired conventional and organic farms. Following Braun-Blanquet procedure, a total of 105 weed species were found. 57 of them were found only in organic, four only in conventional fields and 48 in both. Therefore, there were 105 weed species in organic fields and 52 in conventional fields. More of the endangered species (Red List species) were found in organic fields. Low species diversity observed in 2003 compared to that in 1988 in the same field was attributed to higher temperature and low rainfall in the recent years. The question arises if under increasing temperature and dryness the diversity of species is regressing and endangered the biodiversity of weeds and linked with that also insects and other species as well as offers space for weeds with strong competition to cultivated crops.