Hydraulic adjustment in a pine species across its range

Hydraulic failure due to xylem embolism is a key factor contributing to drought-induced mortality in trees. Studying Pinus canariensis inhabiting an archipelago where migration is limited, López et al. examine traits related to hydraulics and growth in populations under contrasting environments, and measure genetic variability. They find that the ability of P. canariensis to inhabit a wide range of ecosystems seems to be associated with high phenotypic plasticity and some degree of local adaptations of xylem and leaf traits. They infer that divergent selection must have acted in the past on xylem vulnerability to cavitation more strongly than on other traits sensitive to water deficit, such as growth or hydraulic efficiency.