Phenological dynamics of some fruit species from the Northeastern area of Romania in the context of climate change

Climate change has had crucial impacts on phenological stages, such as the advancement or decline of the vegetation cycle of stone fruit trees. Vegetation phenology is an important biological indicator in understanding and predicting the behavior of ecosystems and how they respond to environmental factors. This work aims to investigate the influence of interannual climate variation (years 2023 and 2024) on the phenology of some stone fruit tree species belonging to the genus Prunus. The study was carried out within the fruit experimental plots of the Research Station for Fruit Growing (RSFG) Iași, North-Eastern Romania, analyzing the onset of four phenological stages from bud swelling to the end of flowering at five cultivars belonging to the species: Prunus avium L., Prunus cerasus L., Prunus domestica L. and Prunus armeniaca L. The research conducted on the climatic regime in the studied years, in relation to multiannual values (1972-2022), highlighted the variability of phenological behaviors of stone fruit species both in terms of the number of days (according to the Julian date methodology) for the start of vegetation, and in the duration of phenological stages. Thus, of the two years of study, the year 2024 was noted for an extension of the start of vegetation in cherry by 29 days, in plum by 21 days, in apricotl 12 days and in sour cherry by only one day compared to 2023. The obtained results highlight the variability of the phenological behaviors of the fruit tree species but also of the cultivars and the length of the vegetation period was directly influenced by annual climatic conditions. Changes in the duration of the vegetative phases were highlighted, which can generate useful information to predict the risk of late frosts in particular, but also countermeasures to combat the effects of climate change.