Leaf respiration and its response to environment in different provenances of Larix gmelinii based on exchanging...

Exploring the response of leaf respiration to environmental change and its provenance variation is helpful for understanding the adaptation of trees to environment. We constructed an experiment by transplanting Larix gmelinii seedlings from 11 provenances to two common gardens, and measured leaf respiration and environmental factors. The results showed that leaf respiration rate measured at 15 ℃ (R₁₅), nitrogen concentration and soluble sugar concentration of trees growing in the warm and humid common garden were higher than those growing in the cold and dry common garden. In contrast, leaf respiration rate measured at 25 ℃ (R₂₅) and 35 ℃ (R₃₅), respiration temperature sensitivity coefficient (Q₁₀) and starch concentration of trees growing in the warm and humid common garden were lower than those growing in the cold and dry common garden. This indicated that leaf respiration acclimatized to local environment. R₁₅ was positively correlated with nitrogen concentration and soluble sugar concentration, and negatively correlated with starch concentration. Both R₂₅ and R₃₅ were negatively correlated with nitrogen concentration and soluble sugar concentration, and positively correlated with starch concentration. There were significant provenance differences in the response of R₁₅, R₂₅, R₃₅ and Q₁₀ to environmental change. The environmental effect of R₂₅ was positively correlated with mean annual temperature of origin site, which was the result of long-term adaptation. Our results indicated that leaf respiration of L. gmelinii was controlled by both environmental acclimation and genetic adaptation.