XVI International Botanical Congess

Plants inhabiting subnival zone occur under extreme environmental conditions. However these are optimal for species of the subnival zone. Almost all subnival plants are stenotopes, but they occur almost in every substrate and are successfully adapted to the low temperature and the heating of substrate. The percentage of endemics is the highest in subnival zone of the Caucasus. The following vegetative groups of subnival zone are defined: 1) Solitary growing plants appearing (in common biotope) not having contact either by underground or overground parts, 2) Nanocoenoses dominated by species having contact between overground and underground parts, 3) Fragments of alpine turfy meadows and alpine carpets, 4) Vegetation of certain elements of mesorelief is characterized by non homogenous distribution of species and nanocoenoses.I