The role of grass species in forest communities with Carex brizoides of the Silesian Upland

This paper analyses the role of grass species in transformed forest communities with Carex brizoides L. (sea grass) in the Silesian Upland (southern Poland). In the study area, 27 grass species have been found, more than 30% of which are forest species of the following classes: Alnetea glutinosae, Quercetea robori-petraeae and Querco-Fagetea, and 30% are meadow species (Molinio-Arrhenatheretea). The remnant represent rush communities (Phragmitetea) - 11%, and clear-cut communities (Epilobietea agustiofolii) - 7,5%, single species represent heathes (Nardo-Callunetea), sandy grasslands (Koelerio-Corynephoretea) and mosssedge high moors (Scheuchzerio-Caricetea). The species most often found in forest communities with Carex brizoides are Festuca gigantea, Deschampsia [Avenella] flexousa and D. caespitosa, whoch do not seem to be affected by the presence of sea grass. An analysis of similarities between patches of various communities with Carex brizoides as well as an ordination analysis (PCA) in regard to their specific composition of grass species show that the most frequent grasses and which are in great numbers are an important differentiating factor in the floristically homogeneous phytocoenoses.