Phytophthora cryptogea was isolated from diseased stem base of Aquilegia discolor and rotted leaves of Saxifraga and Sempervivum spp. Additionally, Fusarium species and Botrytis cinerea were frequently isolated from diseased parts of plants. Most of Sempervivum species and cultivars except S. soculiferum were colonized in laboratory conditions by P. cryptogea. The isolates from Alstroemeria aurantiaca, Gerbera jamesonii, Saxifraga arendsii, S. paniculata, Sempervivum arachnoideum colonised houseleek leaves with the fastest spread of necrosis on plant parts inoculated with cultures from Gerbera and S. arendsii. The isolate from S. arendsii colonized 5 species and cultivars of saxifrage as well as Iberis sempervivum, Lavendula angustifolia, Sempervivum sobuliferum and Vinca minor with the slowest development on periwinkle. In laboratory trials isolate of P. cryptogea from houseleek grew on PDA and colonized leaves of that plant at temperature ranging from about 10 to 32.5°C with optimum at 20–30°C.

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.