Syntaxonomical classification of wet woodlands with Picea abies in Slovakia

Wet woodlands with domination of Norway spruce are floristically and ecologically distinctive element of coniferous forest vegetation. However, specialized studies on this vegetation are considerably rare. In this survey the syntaxonomical classification of 145 relevés of Sphagnum-rich and other wet woodlands with Picea abies from Slovakia is proposed. Eight plant communities in the rank of association were differentiated. A distinctive feature of the association Sphagno acutifolii-Piceetum Zukrigl 1973 is the co-occurrence of species typical for climax supramontane woodlands on silicate bedrock of the alliance Piceion excelsae Pawłowski ex Pawłowski et al. 1928 and species characteristic for woodlands of the class Vaccinio uliginosi-Pinetea Passarge 1968. Consequently, this association is classified within the order Piceetalia abietis Pawłowski ex Pawłowski et al. 1928 and alliance Piceion excelsae Pawłowski ex Pawłowski et al. 1928. The rest of wet Picea woodland associations are azonal stable communities (Dauergesellschaften) distributed mostly in the montane zone and they differ floristically as well. Therefore those associations are separated in the floristically well distiguishable order Sphagno palustris-Piceetalia P. Kučera 2019 and they are subdivided into three syntaxa in the rank of alliance: (1) alliance Sphagno palustris-Piceion P. Kučera 2019 comprising the communities limited to nutrient-poor habitats with a shallow peat layer or hydromorphic soils with a substantial raw humus layer: Soldanello montanae-Piceetum Volk in Br.-Bl. et al. 1939, Leucobryo glauci-Piceetum abietis Šomšák ex P. Kučera 2019, Sphagno palustris-Piceetum Šomšák 1979, Equiseto sylvatici-Piceetum Šmarda 1950, and the Carex rostrata-Picea abies community; (2) alliance Stellario nemorum-Abietion albae P. Kučera 2019 with the species-rich spring related association Stellario nemorum-Abietetum albae P.Kučera 2019; (3) base rich alliance Valeriano dioicae-Abietion albae P. Kučera 2019 with the association Valeriano dioicae-Abietetum P. Kučera 2019. Formal definitions and description of species composition of the units are given, as well as brief information on their distribution in Slovakia. Several syntaxonomical and nomenclatural notes are provided in the supplement.