CLIMATOGENIC INFLUENCE AND PREDICTION OF SEASONAL RHYTHM CHANGES IN THE MAIN FOREST-FORMING SPECIES OF THE NORTHEASTERN CARPATHIANS

Abstract

The article is devoted to the study of the phenological phenomena of the main forest-forming species (European spruce - Picea abies, white fir - Abies alba and forest beech - Fagus sylvatica) within the temperate climate zone (600-800 m a.s.l.) on the territory of the Carpathian National Nature Park for the period 2000-2022. The study employed a comprehensive set of field, instrumental, laboratory, analytical, and mathematical-statistical research methods, along with certain approaches applied in phenology and meteorology. According to the results of the statistical analysis, a significant influence of precipitation in March on the beginning of bud swelling (Picea abies and Fagus sylvatica species), the beginning of flowering trees (Picea abies, Abies alba species) and the onset of fruit ripening (Picea abies, Fagus sylvatica species) was revealed. and the beginning of seed dispersal (Picea abies, Abies alba species). It should be noted that the minimum air temperatures in July significantly affect phenological events that begin and continue at this time and later, in particular, the beginning of fruit ripening (Abies alba, Fagus sylvatica species) and the onset of seeds dispersal (in all species). Strong and moderate correlations between January-February maximum temperatures and various phenological events (e.g., in Picea abies, dates of shoot growth and flowering initiation; in Abies alba, dates of flowering initiation and seed ripening initiation; in Fagus sylvatica, dates of bud swelling and flowering initiation) suggest a notable impact of underground water, originating from meltwater during this period, on plant seasonal rhythms. The most difficult for modeling was the phenomenon of the beginning of flowering of trees, the formation of which is influenced by all involved climate predictors - precipitation, minimum and maximum air temperatures. Based on the results of the research, the initial long-term forecasting of the response of local forest crops to probable climate changes was carried out; so, it was shown that even under the worst-case scenario (RCP 8.5), the dates of occurrence of all phenological phenomena of model tree species will be within the scope of the sample of actual data for the observation period of 2000-2022.