No difference in leaf respiration rates among temperate, subarctic, and arctic species grown under controlled conditions

To test the theory that leaf respiration rates are inherently higher in arctic species compared with temperate species, a total of 35 species from temperate, subarctic, and arctic locations were grown under controlled conditions and leaf respiration rates were measured. Regardless of growth temperature (either 10 or 20 degrees C), leaf respiration rates measured at the growth temperature were independent of a species' geographic origin. In addition, salicylhydroxamic acid inhibited the alternative oxidase equally in all groups of species. Acclimation of leaf respiration to temperature was observed in all three geographic plant groups, i.e., leaf respiration rates of 20 degrees C-grown plants were not significantly different than rates of 10 degrees C-grown plants when respiration was measured at the growth temperature. These results suggest that arctic species do not have inherently high leaf respiration rates, higher alternative pathway respiration, or greater temperature acclimation ability compared with temperate species.