Shrub communities dominated by Caragana frutex in the Zhiguli Mountains

Abstract

According to the literature we provide geobotanical analysis of plant communities with the steppe shrubs: Caragana frutex, Cerasus fruticosa, Cotoneaster laxiflorus, Chamaecytisus ruthenicus, Spiraea crenata, Euonymus verrucosus, Amygdlalus nana. The shrub communities occupy the settled areas of the southern slopes of the Zhiguli Mountains (Mogutova, Strel’naya, Bakhilova, Malinovaya, Nablyudatel’). Datasets of relevés were analyzed using the JUICE software package. The cluster analysis was performed using the PC-ORD 5.0 software package. The assessment of the relationship between the ecological characteristics of plant communities and environmental factors was carried out using the L G Ramensky’s indicator values, the IBIS program. DCA-ordination of relevés is performed using the “Ordijuice” module built into the JUICE program from the R package. The studied phytocenoses are divided into three groups. The ecological-phytocenotic and floral characteristics of each cluster are given. Diagnostic, constant and dominant species are established. The list of vascular plant species listed in the federal and regional Red Books, registered in phytocenoses, is given. The results of DCA-ordination of three clusters of shrub communities with a predominance of Caragana frutex are presented. A reliable correlation between the positions of these groups in the space of the DCA-axes and the L G Ramensky’s indicators values (moisture, soil fertility and salinity, pasture digression) was established. Species composition and characteristics of ecotopes in clusters is different. Further study of this shrub communities will reveal the syntaxonomic status.