СLIMATE WARMING TRENDS INFLUENCE ON THE VARIABILITY OF DRY POST-FOREST MEADOWS OF THE VALDAI NATIONAL PARK (NOVGOROD REGION)

Abstract

The data of long-term monitoring of the floristic composition of five sample plots of dry post-forest meadow ecosystems located in different parts of Valdai National Park were presented. These meadows formed as a result of centures-old agricultural practices, then under reservation conditions and climate warming. It has been shown that in the absence of haymaking, grazing, and burning, the meadows exhibit relatively stable floristic composition and abundance of herb layer, a lack of visible successional processes, and resistance to the invastions of alien species. Correlations are found between the number of species, maximum of herb layer height, projective cover of meadow phytocenoses, and weather conditions of a concrete year: seasonal temperature, precipitation amount, and snow depth. It is revealed that different combinations of temperature and precipitation parameters associated with heat and moisture availability are decisive for the formation of plant cover species diversity in all five meadow sample plots. Significant negative correlations with temperature and positive correlations with moisture conditions predominate. Maximum species diversity, maximum of the herb height and projective cover are observed in years with good moisture and temperatures without extreme values.