Interactive effects of [CO2] and water availability on maritime pine

Understanding the interactive effects of elevated CO₂ concentration and water availability on tree functioning is fundamental for the advance of both forest science and global climate change research. In this study, Sánchez-Gómez et al. conduct a controlled experiment in growth chambers with clones of Pinus pinaster with contrasting drought tolerance to test the hypothesis that intraspecific variability in drought tolerance can be modulated by elevated [CO₂].

Intraspecific variation in leaf gas exchange, growth rate and other leaf functional traits was analysed. They find that elevated [CO₂] attenuates genotypic differences in drought tolerance, in terms of photosynthetic performance and growth, as compared with those observed at ambient [CO₂]. This study suggests that elevated [CO₂] can modify the range of drought tolerance across genotypes within tree species.