Temperature responses of leaf respiration in light and darkness are similar and modulated by leaf development

Our ability to predict temperature responses of leaf respiration in light and darkness (R_L and R_Dk ) is essential to models of global carbon dynamics. While many models rely on constant thermal sensitivity (characterized by Q₁₀ ), uncertainty remains as to whether Q₁₀ of R_L and R_Dk are actually similar. We measured short-term temperature responses of R_L and R_Dk in immature and mature leaves of two evergreen tree species, Castanopsis carlesii and Ormosia henry in an open field. R_L was estimated by the Kok method, the Yin method and a newly developed Kok-iterC_c method. When estimated by the Yin and Kok-iterC_c methods, R_L and R_Dk had similar Q₁₀ (c. 2.5). The Kok method overestimated both Q₁₀ and the light inhibition of respiration. R_L /R_Dk was not affected by leaf temperature. Acclimation of respiration in summer was associated with a decline in basal respiration but not in Q₁₀ in both species, which was related to changes in leaf nitrogen content between seasons. Q₁₀ of R_L and R_Dk in mature leaves were 40% higher than in immature leaves. Our results suggest similar Q₁₀ values can be used to model R_L and R_Dk while leaf development-associated changes in Q₁₀ require special consideration in future respiration models.