Evaluation of the impact of frost resistances on potential altitudinal limit of trees

Guillaume Charrier (1) , Hervé H. Cochard (1) , Thierry Ameglio (1)

1 PIAF - Laboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier

Winter physiology of woody plants is a key issue in temperate biomes. Here, we investigated different frost resistance mecha-nisms on 1-year-old branches of 11 European tree species from November until budburst: (i) frost hardiness of living cells (by electrolyte leakage method), (ii) winter embolism sensitivity (by percentage loss of conductivity: PLC) and (iii) phenologi-cal variation of budburst (by thermal time to budburst). These ecophysiological traits were analyzed according to the poten-tial altitudinal limit, which is highly related to frost exposure. Seasonal frost hardiness and PLC changes are relatively different across species. Maximal PLC observed in winter (PLC Max) was the factor most closely related to potential altitudinal limit. Moreover, PLC Max was related to the mean hydraulic diameter of vessels (indicating embolism sensitivity) and to osmotic compounds (indicating ability of living cells to refill xylem conducting elements). Winter embolism formation seems to be counterbalanced by active refilling from living cells. These results enabled us to model potential altitudinal limit according to three of the physiological/anatomical parameters studied. Monitoring different frost resistance strategies brings new insights to our understanding of the altitudinal limits of trees.

Mots clés: budburst; frost hardiness; living cell; tree ecophysiology; winter embolism

Domaines: Biologie végétale

Guillaume Charrier, Hervé H. Cochard, Thierry Ameglio. Evaluation of the impact of frost resistances on potential altitudinal limit of trees. Tree Physiology, 2013, 33, pp.891 - 902. ⟨10.1093/treephys/tpt062⟩. ⟨hal-01089605⟩