Ladder spleenwort (Asplenium adulterinum Milde) in Poland–distribution, population state and conservation plan framework

Ladder spleenwort Asplenium adulterinum Milde (Aspleniaceae) is the rare fern, since long time believed to be one of species which determine distinctive character of Lower Silesian flora (e.g. Pax 1915, Szafer 1972). A. adulterinum was considered as a European endemic species (Reichstein 1984) but it has been found also on the Vancouver Island at the west coast of Canada Käsermann (1999), Klinkenberg (2008). Its European sites are concentrated in the Alpine area and in the Middle European mountain ranges of the Hercynian orogeny. The species range comprises also isolated sites scattered through the Fennoscandia as well as on the Balkan Peninsula (Jalas and Suominen 1972). The species is almost strictly related to serpentine rocks and only exceptionally occurs on the other substrata. Lower Silesia is the only region in Poland with the serpentine outcrops and therefore is also only area of A. adulterinum occurrence in the country. The species is regarded as seriously threatened with the IUCN category from EN – endangered (Żołnierz 2001; Fabiszewski, Kwiatkowski 2002) to CR – critically endangered (Świerkosz, Szczęśniak 2003). The category CR is also attributed to A. adulterinum in Czech Republic and Slovakia (Čeřovský, Klaudisová 1999). Ladder spleenwort was included in the list of species, which has been proposed by Poland to expand the appendix II of the Habitat Directive (92/43/EEC Directive) as Species of Community Interest whose conservation requires the designation of Special Areas of Conservation. It also listed in Annex IV between plans species need of strict protection in all European Union country. From this reason in Poland law Asplenium adulterinum is listed as species which not only need protection, but also establishing of special protection zone around the each locality is necessary.