Climatic variables influence the photosynthetic capacity of forest plantations in Brazil

Abstract

Realistic representations of plant carbon exchange processes are necessary to understand the growth and productivity of forests and to understand how plants will behave in future climate change scenarios. These processes are known to vary over depending on environmental and genetic factors. Here, we used the model by Farquhar et al. (Plant 149:78–90, 1980) to obtain the parameters Vcmax, Jmax and Jmax/Vcmax, and we analyzed the influence of growth temperature and precipitation variables and climatic groups on these parameters for the two functional groups (pine and eucalypt). Our results show that the photosynthetic capacity of forests has a difference between the functional groups, the variables growth temperature and precipitation at 10 and 30 days before physiological measurements influenced photosynthetic parameters, indicated a tendency to increase in photosynthetic capacity, suggesting its acclimatization to the environment. There were no differences between the subtropical and tropical climatic groups, demonstrating an adaptation of the genotypes to the environmental conditions of Brazil. The values of Vcmax, Jmax and Jmax/Vcmax parameters provided in this study expand the database of photosynthetic parameters and can be widely used in modeling studies of planted forests in Brazil. However, they should be interpreted with caution, we recommend specific field studies to fit models and further studies comparing species groups in Brazil.