PHENOLOGICAL AND GROWTH-PATTERNS OF THE MEDITERRANEAN OAK QUERCUS-SUBER L

The phenology of Quercus suber L., a dominant species of the montados in the Iberian Peninsula, was studied for 2 years in southwest Portuga l. The seasonal progression of phenological events was analyzed in sev en trees. Selected branches were examined monthly for shoot elongation , leaf number, branching, flowering, and fruiting. Radial stem growth and specific leaf weight were also studied. Active growth was observed from early spring to early summer. Reserves accumulated during winter and high photosynthetic activity in early spring apparently supported this strong development. The growth flush started with stem radial in crement, which seemed to be impaired by spring rainfall. Male inflores cence production was the next phenological event. Old leaves were shed during new twig and leaf emergence. Shoot elongation and the number o f new leaves produced were well correlated with the previous-year shoo t's length, and were not clearly related to climatic factors. Radial g rowth resumed in autumn at a lower rate than in the previous spring, a possible consequence of a reserve depletion due to lower photosynthet ic production in summer and investment on fruit maturation, which was complete by late autumn. Premature and excessive new leaf production w ere apparently subjected to self-pruning strategies related to the dev elopment of each tree's crown. Younger cork-oaks produced shorter and fewer shoots per module, and more sclerophyllous leaves than the older ones. A high intra-specific variability was observed in all the resul ts.