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The aim of our study was to reveal the differences in the species composition and soil properties of open sandy grasslands dominated by different Festuca species, Festuca vaginata and F. pseudovaginata. Due to the arid conditions, sandy grasslands are generally covered by xerothermic vegetation in which F. vaginata is a typical dominant species. Festuca pseudovaginata, a species newly described by the authors, can also gain dominance in sandy grasslands. However, species composition and soil properties of grasslands dominated by this recently discovered species are still undiscovered. Based on previous coenological studies, we hypothesised that the grasslands characterised by the endemic F. vaginata are more species-rich than those with F.pseudovaginata.
Coenological sampling was carried out in May 2009 at two study sites using the Braun-Blanquet method in quadrats of 2 m × 2 m. Five relevés were sampled in stands dominated by F. vaginata and F. pseudovaginata respectively at two study sites in Central Hungary, resulting in a total of twenty relevés. Analyses were based on the cover scores of vascular plant species and cryptogam crust and values of seven soil properties (pH [KCl], pH [H2O], humus, total N, Ca, P2O5 and K2O) measured in the 0–15 and 15–30 cm soil layers. Soil properties of the grasslands dominated by F. pseudovaginata and F. vaginata (dependent variables) were compared by linear mixed models, where ‘grassland type’ was the fixed factor and ‘site nested in grassland type’ was considered as random factor. Data were analysed by cluster analysis, fusion algorithm was a combinatorial method (minimising increase of variance), and the correlation was used as comparative function. We compared the cover of subordinate species by Mann-Whitney U test. We found that F. pseudovaginata and F. vaginata samples were well separated, and grasslands dominated by F. pseudovaginata had nearly two times more species than those dominated by F. vaginata. Based on the cluster analyses using plant cover and upper 0–15 cm soil layer data, F. pseudovaginata and F. vaginata groups could be well separated. Linear mixed models revealed that F. vaginata grasslands were typical on soils with higher pH, nitrogen, phosphorous and potassium contents compared to F. pseudovaginata grasslands, which indicates a tight connection between the properties of the upper soil layer and the vegetation in sandy grasslands.
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.
The spider fauna of buildings and other urban habitats (city parks, green areas of industrial enterprises, and housing estates) of Chernivtsi city was surveyed. In the period 2002-2011, 212 species belonging to 26 families were recorded. Previous studies found a total of 173 species of spiders belonging to 26 families from the territories which are now included in the city limits of Chernivtsi. Currently, the total spider species list for Chernivtsi includes 260 species of 30 families, of which 125 species (21 families) were recorded both by earlier researchers and by ourselves. The most important reasons for changes in urban spider assemblages are as follows: species habitat change, introduction of alien species, and description of new species unknown in the late 19th – early 20th centuries.
A systematic survey of grassland communities in central Slovakian sub-montane and montane regions (including the Kremnické vrchy Mts., Starohorské vrchy Mts., Veľká Fatra Mts., and Zvolenská kotlina Basin) was performed between 1996 and 2007. The main aim was to identify main environmental gradients in the studied vegetation and to estimate the most important individual variables responsible for the variation of their species composition. Along with the floristic composition, the environmental variables were either recorded in the field (altitude, slope, aspect), calculated (solar radiation, climatic data, and phytochorological affinity), or derived from available maps or GIS digital data layers (type of bedrock, soil parameters). These environmental variables were used as supplementary in the detrended correspondence analysis (DCA) or explanatory in the canonical correspondence analysis (CCA). The affiliation of individual phytosociological relevés to associations was estimated by an electronic expert system for Slovak grassland communities. Altogether, 15 xero-, sub-xero- and mesophilous grassland associations were distinguished. Wet and fen meadows were analysed at the level of alliances. Unconstrained ordination revealed moisture and nutrient gradients as most important for the data set. By means of constrained ordination, the variability of the studied vegetation could be explained by a set of geological, topographic, phytochorological and derived climatic variables, although the percentage of explained variance was rather low and did not exceed 12% for all significant factors combined. Among individual variables, the geological bedrock type, climatic water balance, solar radiation, and slope played the most important role in determining the distribution and variability of individual grassland communities. Affinity to phytochorions determined according to local air temperature gradients was also significant. Soil properties played only a subordinate role in our analyses. The analysis of a more homogeneous subset of the data without wetland relevés gave similar results as the analysis of the complete data set. The differences in results of constrained and unconstrained ordinations are discussed together with the potential reasons for extremely high proportion of unexplained variance revealed by the variation partitioning methods.