Differences between provenances and pedunculate oak (Quercus robur) trees after the lethal dose (LD50) of electrolyte leakage

The study conducted on pedunculate oak cultures of different provenances from the ,,Plaiul Fagului” Scientific Reserve evaluated the level of electrolyte leakage from leaves after the application of a lethal heat shock (DL50). The results indicate a significant physiological variation in the response of trees to heat stress. Analysis of variance revealed significant differences between pedunculate oak provenances, indicating a greater resistance to heat shock in the descendants of trees from more distant origins (Edineț and Baimaclia) compared to those from the central area (Plaiul Fagului and Hâncești), where the common arboretum is installed. It can be assumed that there is a significant variation in the physiological response of trees from different provenances to thermal stress, and descendants from more distant areas have exhibited a more pronounced adaptive response than those from areas closer to the common arboretum, which have similar environmental conditions to the cultivation area. The preliminary results of the study suggest that the selection of the best trees and provenances for afforestation can be made based on the resistance of oak trees to heat stress. In addition, the adaptation of trees to specific environmental conditions can be improved through the selection of these provenances, especially for future afforestation in the context of climate change.