Soligenous wetlands of North-western Poland as an environment for endangered mire species

Abstract

Environmental conditions and the occurrence of protected and rare species have been studied in 18 groundwater-fed wetland complexes in north-western Poland. The plant cover of studied objects consisted of 81 syntaxa of water-, spring-, rush and sedge-, mire-, meadow-, tall-forb-, willow carr- and alderwood communities, as well as of 4 syntaxa of the mesophytic forests. Their microhabitat differentiation has been discussed. The expression of environmental conditions in the groundwater-fed communities has been analysed on the basis of Ellenberg's indicator values and the occurrence of protected and rare species. A signifficant negative correlation has been found between the occurrence of rare species and the trophy index. The special position of the mesotrophic rich fen communities, concerning their role in preservation of a large number of endangered species, as well as of rare plant communities is emphasized.