Occurrence Of Native Weed Species On Arable Land - Effect Of Different Environmental Factors

Native species form a substantial part of arable weed communities. The objective of this survey was to study the occurrence of native species in arable fields in the Czech Republic related to applied management systems (conventional and organic farming), crops (winter cereals, spring cereals, wide-row crops) and environmental conditions at different altitudes. In 2006-2018, a phytocoenological survey (320 releves) was performed across the Czech Republic. In total, 180 weed species were recorded, of which 43.33% were considered as native (78 species). The net effects of all the studied variables on the occurrence of native species were found as statistically significant. Most of the variability was explained by the altitude, followed by the crop and type of farming. The highest occurrence of native weeds was noticed in organic farming and cereals and increased with an increasing altitude. The higher incidence in higher elevations can be connected to the more intensive agriculture in the lowlands.