Participation of Solidago gigantea Aiton in plant communities of chosen midfield biotopes on Central Pomerania.
The paper presents the results of the research on ruderal and segetal communities with Solidago gigantea on Middle Pomerania (North Poland). Giant goldenrod introduced from Northern America, was first observed on Middle Pomerania in the 1868 year. Today, it is one of the weeds causing high severe economic and nature conservation losses. It especially infests perennial crops, former manor parks, fallows, meadows and pastures. Solidago gigantea is one of the species that use stream and river valleys as specific ecological corridors along which they disperse. Giant goldenrod was found on the banks of the Łeba, Słupia, Grabowa and Parsęta rivers. The species sometimes forms closed, mono-dominant populations of several hectares, occupying habitats of native plants species. Phytocoenoses where species was found were subject to phytosociologiocal analysis by taking phytosociological relevés of the patches where it grew, using Braun-Blanquets method. Patches of perennial herbaceous vegetation from Artemisietea vulgaris class with Solidago gigantea were classified as: Aegopodio-Petasitetum hybridii, Agropyro repentis-Aegopodietum podagrariae, Heracleeteum mantegazziani from Petasition officinalis alliance, Impatienti glanduliferae-Convolvuletum sepium, Polygonetum cuspidati from Senecionion fluviatile alliance. Some individuals of Solidago gigantea were noted in such segetal plant communities from Stellarietea mediae class as: Veronico agrestis-Fumarietum officinalis, Oxalido-Chenopodietum polyspermi, Euphorbio peplidis-Galinsogetum ciliatae from Veronico-Euphorbion alliance, Spergulo-Echinochloetum cruris-galli and Spergulo arvensis-Scleranthetum annui from Panico-Setarion alliance.