Conservational importance of the arable weed vegetation on extensively managed fields in western Hungary

The present study surveyed the weed vegetation on extensively managed fields in Western Hungary, based on 1698 phytosociological records collected between 1995 and 2005. The surveyed vegetation units supported 41 red list weed species. The sum of mean frequencies of red list weed species was about 5 times higher in cereal fields than in stubbles and 6 times higher than in row crops. The proportion of insect-pollinated plant species was approximately 72% in cereal, 66% in stubble and 50% in row crop weed communities. About 43% of the weed species composition in cereal fields, 52% in stubbles and 54% in row crop fields also offered seed food sources for threatened farmland birds, e.g. Coturnix coturnix and Perdix perdix. Therefore, extensively managed fields should deserve a high conservation priority for biodiversity The factor that offers the greatest threats to the continuing existence of these habitats in addition to abandonment and intensive agricultural management is the increasing spread of Ambrosia artemisiifolia.