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