Associations and communities of cereal crops of the Łuków Plain. Part III. Intermediate and impoverished communities

This paper is the third and final part of a study attempting to analyse associations and communities in cereal crops of the Łuków Plain. It contains a description of intermediate and impoverished communities established in cereal crops of the Łuków Plain. Patches with phytocenoses without the combination of species characteristic of cereal associations were frequently observed. Impoverished communities of the alliance Aperion spicae-venti established in winter cereal crops. In turn, in spring cereal crops phytocenoses including species characteristic of tuber and root crops were found; they represented either a community with species characteristic of Panico-Setarion or an intermediate community with species characteristic of Aperion spicae-venti and Polygono-Chenopodion. Such communities are established, among others, because of production intensification which changes habitat conditions. Some patches found in the study area were intermediate between the two most frequently observed associations Arnoserido-Scleranthetum and Vicietum tetraspermae