Spatio-temporal study of wood formation of Quercus robur L. and Q. pyrenaica Willd. in the Northwest of the Iberian Peninsula

This study on ecological wood anatomy contributes to the knowledge on the process of xylem formation and its associated climatic patterns, which are fundamental to establish a correct interpretation of the cause-effect relationships observed in dendrochronological retrospective analyses of ring-porous species. For this purpose, the process of wood formation (xylogenesis) and leaf phenology were monitored during two years at 14 sites of natural forests (nive for Quercus robur, and five for Q. pyrenaica). A retrospective (dendrochronological) study of tree rings and anatomical variables (earlywood vessels) was also carried out at four out of the 14 sites. Climate-growth relationships at the 14 sites were analyzed, the synchronicity between wood growth and leaf development was described, and the water content of crown organs (branches, buds, leaves) was quantified to minimize observer’s subjectivity for leaf phenology