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Thermal acclimation of photosynthesis: a comparison of boreal and temperate tree species along a latitudinal transect
Author(s) -
DILLAWAY DYLAN N.,
KRUGER ERIC L.
Publication year - 2010
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2010.02114.x
Subject(s) - liquidambar styraciflua , temperate climate , transect , photosynthesis , acclimatization , botany , biology , taiga , rubisco , boreal , stomatal conductance , ecology
Common gardens were established along a ∼900 km latitudinal transect to examine factors limiting geographical distributions of boreal and temperate tree species in eastern North America. Boreal representatives were trembling aspen ( Populus tremuloides Michx.) and paper birch ( Betula papyrifera Marsh.), while temperate species were eastern cottonwood ( Populus deltoides Bartr ex. Marsh var. deltoides) and sweetgum ( Liquidambar styraciflua L.). The species were compared with respect to adjustments of leaf photosynthetic metabolism along the transect, with emphasis on temperature sensitivities of the maximum rate of ribulose bisphosphate (RuBP) carboxylation ( E V ) and regeneration ( E J ). During leaf development, the average air temperature ( T growth ) differed between the coolest and warmest gardens by 12 °C. Evidence of photosynthetic thermal acclimation (metabolic shifts compensating for differences in T growth ) was generally lacking in all species. Namely, neither E V nor E J was positively related to T growth . Correspondingly, the optimum temperature ( T opt ) of ambient photosynthesis ( A sat ) did not vary significantly with T growth . Modest variation in T opt was explained by the combination of E V plus the slope and curvature of the parabolic temperature response of mesophyll conductance ( g m ). All in all, species differed little in photosynthetic responses to climate. Furthermore, the adaptive importance of photosynthetic thermal acclimation was overshadowed by g m 's influence on A sat 's temperature response.