Phytosociological and ecological relations in the communities with the share of Carex chordorrhiza L. f. inside and outside the dense geographical species range

Abstract

The aim of this study was to investigate and evaluate the sociological relations of communities with the share of C. chordorrhiza L. f. in the area inside the dense geographical range (IGR), and to compare the data with records from outside the dense geographical range OGR). We also described the environmental conditions with the use of the phytoindication method, and indicated phytocoenotic factors affecting the protection of the population of this threatened species.String sedge was most frequently noted in the Sphagno-Caricetum rostratae association. The OGR communities contain a smaller number of species, and especially of trees, shrubs and herbaceous plants. Eriophorum vaginatum, Sphagnum capillifolium, Lysimachia vulgaris, Scheuchzeria palustris, Polytrichum strictum, or Straminergon stramineum, i.e., species whose frequency and coverage is high in the IGR communities, were not observed here. The IGR communities are found in relatively poor and highly acidified habitats, whereas the OGR communities occur in various habitats and are more diverse floristically. The present results demonstrate that large threat for C. chordorrhiza is posed by tree and shrub expansion (Betula pubescens, B. pendula and Salix cinerea), which has been reported for many years and is often caused by drainage.