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 Q 10 ), uncertainty remains as to whether Q 10 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 Q 10 (c. 2.5). The Kok method overestimated both Q 10 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 Q 10 in both species, which was related to changes in leaf nitrogen content between seasons. Q 10 of R L and R Dk in mature leaves were 40% higher than in immature leaves. Our results suggest similar Q 10 values can be used to model R L and R Dk while leaf development-associated changes in Q 10 require special consideration in future respiration models.