Pflanzensoziologische Studien der Ackerunkraut-Gesellschaften in der Slowakei

A phytosociological survey of weed (segetal) vegetation in Slovakia was performed. A total of 508 relevés were sampled in 2002–2008. The aims of this study were to determine the actual distribution of the segetal communities, to analyze their floristic structure, and to evaluate their relationships to selected environmental factors. Thirteen plant communities of the class Stellarietea mediae were distinguished by cluster analysis; 11 communities were included in the subclass Violenea arvensis (Lathyro tuberosi-Adonidetum aestivalis, Consolido-Anthemidetum austriacae, Euphorbio exiguae-Melandrietum noctiflori, Veronicetum trilobae-triphyllidi, Lamio amplexicauli-Thlaspietum arvensis, Taraxacum sect. Ruderalia community, Spergulo arvensis-Scleranthetum annui, Myosotido-Sonchetum arvensis, Echinochloo-Setarietum pumilae, Galinsogo-Setarietum, and Stachyo annui-Setarietum pumilae) and two in the subclass Sisymbrienea (Portulacetum oleraceae and Setario viridis-Erigeronetum canadensis). Communities were characterized by diagnostic, constant, and dominant species and their structure, ecology, and distribution were estimated. The species composition of these communities was documented in synoptic and association tables. DCA ordination and analysis of variance was used to determine the main environmental factors of floristic differentiation and to determine ecological and structural differences among the communities. The analyses showed that the most important factors affecting floristic composition and classification of the weed communities are their time of development (agroecophase), the type of crops and altitude.Die ersten Untersuchungen zur Segetalvegetation in der Slowakei sind erst nach dem 2. Weltkrieg durchgeführt worden. Seitdem haben sich verschiedene Autoren mit der Untersuchung dieser Vegetationstypen beschäftigt, dieses Interesse schwand jedoch seit den 1980er Jahren. Die Ziele dieser Arbeit sind, folgende Aspekte zu untersuchen und zu analysieren: (i) die aktuelle Verbreitung der Segetal-Pflanzengesellschaften in der Slowakei, (ii) die floristische Zusammensetzung der Pflanzengesellschaften (Lebensformen, Herkunft der Sippen und Fragen nach dem Status als invasive Arten, Vorhandensein von gefährdeten Sippen) sowie (iii) ihre Beziehungen zu ausgewählten Umweltfaktoren