The alien moss Orthodontium lineare Schwägr. in Poland (East-Central Europe): a summary of nearly 40 years of invasion

Orthodontium lineare, a neophyte of southern origin, was accidentally introduced by human activity to England in 1910. Subsequently it spread to mainland Europe and it continues to move eastward. In Poland, it was discovered in 1980–1981. The present paper shows dot distribution maps at 10-year intervals and discusses the dynamics of its invasion and ecological preferences using statistical methods. In Poland in 2018 it was known in 235 stands. 86.4% of them were located below 300 m a.s.l. and only 10.2% of the sites reached the lower mountain forest belt (maximum altitude 915 m). On every substrate and in all types of habitat, it commonly produced sporophytes (88.6% of the specimens investigated). Most commonly it occurred on rotting wood (38.5% of all records) and the base of tree trunks (33.9%). Rarely it grew on soil (podzolic and acid podzolic brown soils and humus on rocks; in total 19.0%). Most frequently it was found on the dead wood of Pinus sylvestris (31.3% of all records on rotting wood) and Picea abies (23.2%) and on the bases of P. sylvestris trunks (77.0%). Up to 2018 it was listed in 13 habitat types, including eight EU habitats (two priority), the most often invaded being semi-natural forest (25.8% of all records), boggy woodland (23.4%), mature managed forest developed from old plantations (17.7%), wooded dunes of the Atlantic region (9.7%) and Luzulo-Fagetum beech forest (6.9%). 33 accompanying taxa were found comprising 6 liverworts, 23 mosses and 4 lichens. Of these only 7 species were present in more than 5% of the samples.