Alien invasive as well as rare and endangered species in the agrocenoses of the Ułęż commune

Abstract

The paper analyses the presence of invasive alien species and rare taxons among crop weeds in the Ułęż commune. The study is based on phytosociological relevés taken according to the Braun-Blanquet method. In total, 99 phytosociological relevés were taken. The research was conducted in 2016 and 2017. Ten rare regional and cross-regional species were found among weeds in cultivated crops. These were: Agrostemma githago, Arnoseris minima, Avena strigosa, Chenopodium polyspermum, Consolida regalis, Veronica opaca, Veronica polita, Veronica agrestis, Bromus secalinus, and Centaurea cyanus. Some of the most common species in that area included Centaurea cyanus and Bromus secalinus, while Avena strigosa also belonged to frequent components of the local flora. Other species were recorded rarely or very rarely. Additionally, in the crops, there was a group of 16 invasive alien species. Setaria pumila had the largest vegetal cover and the largest number of positions. There were some more frequently recorded species like Echinochloa crus-galli, Galinsoga parviflora and Conyza canadensis, with Avena fatua being quite common as well. Other species quite often found were: Amaranthus retroflexus, Galinsoga ciliata, Veronica persica and Oxalis fontana. However, species such as Setaria viridis, Solidago canadensis, Bidens frondosa, Epilobium ciliatum, Alopecurus myosuroides, Bromus sterilis and Parthenocissus inserta were rarely or very rarely found in the crops.