|Abstract: ||Upper Jurassic Cuesta is a specific landform – a ridge that defines the border between the Silesian Upland and the Kraków-Częstochowa Upland. Its characteristic feature is a large diversity of environmental conditions, mainly due to its geological structure and geographical extent.
The plant cover of this area has not been studied so far, only fragments of this area have been surveyed (Szczypek, Wika 1995, Babczyńska-Sendek, Barć 2009, Babczyńska-Sendek et. al 2014; Babczyńska-Sendek et. al 2015). Due to the specific environmental features of this ridge, a large diversity of flora and vegetation was expected, thus detailed phytosociological and floristic studies were undertaken. A total of 263 phytosociological relevés were performed and 201 floristic inventories were carried out. Moreover, 73 soil samples were collected and analyzed. The classification of phytosociological data set was made using the TWINSPAN analysis. Detrended correspondence analysis (DCA) was used in order to identify the key environmental variable influencing the diversity of vegetation. The canonical correspondence analysis (CCA) was used to determine the relationship between vegetation and soil properties. The vegetation was analyzed in terms of phytocoenotic and functional diversity, as well as in terms of occurring disturbances. The Z Disturbance Index (Kącki 2012) was used for this analysis. Floristic diversity was investigated in the 16 designated research sections, and the synthesis of the data was made in relation to three main parts of the studied area (northern, central and southern).
In the studied area 23 vegetation units were identified (communities and associations). The largest share in the vegetation cover were Molinio-Arrhenatheretea meadows communities (31% of all phytocoenoses studied), Festuco-Brometea grasslands (23%) and Rhamno-Prunetea shrubs (18%). The most common plant community in this area was Pruno-Crataegetum (16%). The vegetation diversity was reflected in the diversification of its functional structure. The most important functional traits, which distinguish studied plant communities, were selected. For forest vegetation they were among others: SLA, seed mass and share of competitors; and for non-forest vegetation, among others: share of species with different life strategies, plant height, type of reproduction and seed mass. It was shown that the studied environmental variables explain 24% of variation of the cuesta vegetation. The main vegetation changes indicators of the studied area are: share of plants with a competitive strategy; share of low (less than 30 cm), erosulate and semi-rosette species; and small seeds plants. A total of 682 vascular plant species were found in the area of Upper Jurassic cuesta. The vast majority are native plants. The floristically richest is ‘Włodowice’ research sections, where 357 species of vascular plants were found, which constitutes 51% of the entire flora of this area. The core of flora in particular parts of the cuesta is similar, significant differences between them were demonstrated in the case of the participation of the most valuable elements of flora and species belonging to various sociological and ecological groups. The most valuable elements of the flora of this area were among others: 1 species from the Polish Red Book of Plants: Orobanche bartlingii, 29 species of the Polish red list of ferns and flower plants, 135 threatened species of the Silesian Province and 46 species covered by legal protection. Two species (Silaum silaus and Carex michelii) reach the limit of their natural range in this area. Five natural habitats of European importance were identified in the studied area. Based on the research findings, the most valuable fragments of vegetation were identified and protective recommendations were specified.|