Physiological and Morphological Variation in Balsam Fir Provenances Growing in New Brunswick, Canada

There is a need to understand the physio-morphological responses of northern tree species climate change. The hypothesis current study was that provenance and light intensity were both influential in control intrinsic water-use efficiency (iWUE). Diameter at breast height (DBH)-increment hypothesized as being more affected by provenance. Intrinsic (iWUE), ratio photosynthesis (A) stomatal conductance (gs), assessed foliage under two levels photosynthetically active radiation (PAR; i.e., 300 1200 ?mol m?2 s?1) 63-year-old balsam fir [Abies balsamea (L.) Mill.] provenances derived from seed sources across species’ natural range (namely, within 44–51° N latitudes 53–102° W longitudes) cultivated common garden eastern Canada. (DBH) measured when they 42 58 years old (DBH1998, DBH2014). results confirmed hypotheses regarding roles on iWUE DBH (p < 0.05), but showed diminished role PAR iWUE. lowest highest mean among ranged between 0.028 0.031 0.079–0.083 mmol?1 11.82–12.78 16.38–18.44 cm, respectively. Stomatal had strong relationship with settings, whereas A weaker no significant relationships settings climatic variables source > 0.05). 2014 significantly greater than DBH1998 DBH2014 statistically positive 2014. Survivorship shown vary DBH-increment. show for present-day future forest management, (i) selection fir, relation should ideally be based criterion intraspecific conductance; (ii) shade tolerance population differentiation, consistent pace DBH-growth variable conditions are important factors sustained growth changes dynamics projected accompany regional climate; (iii) temperature indicators DBH-increment fir; (iv) effect size its survival maintained conditions; (v) there clear association radial growth.