Phenology and biochemical analysis of spontaneous Prunus spinosa L. population in the victinity of Belgrade

The aims of the research were to determine the variability of the phenological patterns of natural populations of Prunus spinosa L. in the ecotones of the southeastern part of the Balkan Peninsula and to create an informational database regarding the impact of air temperature and precipitation on the phenology of this species, based on research conducted during the period from 2007 to 2024. The obtained data were analysed using descriptive and multivariate statistical methods. The results showed that the onset of spring phenological phases has been significantly accelerated by the increase in air temperature, especially in 2024, when flowering started 31 days earlier, the flowering phase lasted 13 days longer, and fruit ripening occurred 65 days earlier compared to the 2007-2023 period. The content of phenols, flavonoids, anthocyanins, and antioxidant activity in fruits was determined in distilled water and 70% ethanol. The analysed extracts contained a high percentage of phenols and demonstrated significant antioxidant activity. The obtained results are the starting point for studying changes in the phenological patterns of blackthorn in response to climate change under the agro-ecological conditions of the southwestern suburb of Belgrade. The study confirmed the adaptability of blackthorn, except for the vulnerability of its flowering phenophase to late spring frosts, as observed in 2023. The resilience of the species to climatic challenges was further confirmed by its drought tolerance in 2024 and a significant correlation between fruit ripening and high air temperatures during the growing season over 18 consecutive years of research.