Ermakov N.,Laboratory Ecology and Geobotany |
Larionov A.,Laboratory Ecology and Geobotany |
Polyakova M.,Laboratory Ecology and Geobotany |
Pestunov I.,Russian Academy of Sciences |
Didukh Y.P.,Institute of Botany of NAN Ukraine
Tuexenia | Year: 2014
Cryophytic steppes in the Minusinskaya intermountain basin containing plant species that are pre-dominantly distributed in the alpine zone such as Androsace dasyphylla, Dryas oxyodonta, Festuca sphagnicola, Kobresia myosuroides, K. filifolia, Minuartia verna, Oxytropis bracteata, Sagina sagi-noides, Papaver nudicaule, Patrinia sibirica, Pedicularis lasiostachys, Pulsatilla ambigua, Saussurea schanginiana, which are considered remnants of the Pleistocene vegetation. Based on 89 relevés, we classified cryophytic steppes using the Braun-Blanquet method within two phytosociological classes: Central Asian steppes of the Cleistogenetea squarrosae and West Palearctic steppes of the Festuco-Brometea. Three associations (Androsaco dasyphyllae-Caricetum pediformis, Pulsatillo patentis-Caricetum pediformis and Bupleuro multinervi-Helictotrichetum desertori) with three subassociations and three variants were described with respect to their phytosociological affinities and ecology. DCA ordination showed floristic differences between syntaxa, while correlations of DCA axes and floristic and environmental variables detected substrate type and temperature regime as presumably main driv-ers for vegetation differentiation. Another driver for vegetation differentiation seems to be continentali-ty of the climate. Small scale distribution of cryophytic steppes were mapped using satellite images with resolution of 1.8 m. Cryophytic steppes always occupy only small areas in landscapes, on convex parts of undulated micro-relief of mountain slopes and summits characterised by drought in summer and deep soil freezing in winter. These special micro-ecological conditions play an essential role for the existence of alpine flora in the Minusinskaya intermountain basin.