The paper deals with the structural variability and generative reproduction of Saxifraga oppositifolia populations in eight localities situated in Western Spitsbergen. The localities differed in terms of humidity, soil fertility, microclimate and frequency of disturbances. The population structure, the growth and development rate of individuals in the sea terrace and at the peat-bog prove that a dense plant cover influences positively the development of S. oppositifolia. The size of individuals, their biomass and population density is limited in most of the studied localities. Solifluction is the factor influencing the development of a population to the greatest extent. Of all the researched populations the weakest development was observed in the active structural grounds. Yearly changes in the structure of the populations as well as the yearly growth of the species studied are limited. The longevity, the development rate and size of the seedling recruitment are subject to modifications caused by the solifluction.
Changes taking place in weathered bedrock and vegetation of the ground moraine of Werenskiold glacier during about 50 years are presented. These results are based on phytosociological survey and analysis of the population structure of Saxifraga oppositifolia in 20 experimental fields and the analysis of physical and chemical features of the soils. In the process of succession, with chemical features not much changed and spongy structure just beginning, the number of vascular plants did not increase. In the process of succession the gradual increase in the density of S. oppositifolia population was observed. The size of its individuals and the share of flowering individuals also increased.