Vitality of Rubus arcticus L. in medium and southern taiga

Vitality strategies for 11 coenopopulations of arctic bramble (Rubus arcticus L.) were defined in conditions of medium and southern taiga on the edge of the species range. In studied conditions optimal habitats for R. arcticus growth, while maintaining high vitality index, are open meadows and coniferous-small-leaved forests with high level of soil moisture: Epilobium-gramineous wet meadow formed on a runway and surrounded by spruce-birch forest with pine and aspen-birch herbaceous forest with spruce. The study showed that the pedicel length, width of the central lobe of the 3rd leaf from the metamere base, and number of living leaves are the most sensitive features which react to the state of environment. R. arcticus shows 3 ontogenetic tactics near the border of its range: divergent, convergent and stabilizing tactic. Most of morphological features studied prove divergent character of ontogenetic tactic, which determines the increase in features' variability in close-to-stress conditions. Near its southern border arctic bramble uses defensive strategies for survival allowing its successful vegetative reproduction. According to the results of the study and species' ecological peculiarities and in order to achieve effective monitoring and prognosis of the species' state, it is important that we apply complex estimation of variability of physiological-biological and morphological parameters of R. arcticus.