Phenological and growth patterns of the Mediterranean oak Quercus suber L.

Abstract

Abstract. The phenology of Quercus suber L., a dominant species of the montados in the Iberian Peninsula, was studied for 2 years in southwest Portugal. The seasonal progression of phenological events was analyzed in seven 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 increment, which seemed to be impaired by spring rainfall. Male inflorescence production was the next phenological event. Old leaves were shed during new twig and leaf emergence. Shoot elongation and the number of new leaves produced were well correlated with the previous-year shoot's length, and were not clearly related to climatic factors. Radial growth resumed in autumn at a lower rate than in the previous spring, a possible consequence of a reserve depletion due to lower photosynthetic production in summer and investment on fruit maturation, which was complete by late autumn. Premature and excessive new leaf production were apparently subjected to self-pruning strategies related to the development 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 results.

Are ecophysiological responses influenced by crown position in cork-oak?

“…These results, together with those previously reported on inter-tree variability (Oliveira et al, 1992(Oliveira et al, , 1994, should be taken into account when planning field research in similar stands. Moreover, this work may provide some useful information for future modelling of oak productivity in these woodlands.…”

Map-Making of Plant Biomass and Leaf Area Index for Management of Protected Areas

“…1999) and leaf area index, vertical and horizontal denseness are important structural parameters of vegetation (Barkman 1988). Many predictions of future climate include an expectation that changes in average values of climatic variables may modify the intensity and the interaction of environmental stresses on plants (Naveh and Lieberman 1990); besides, considerable attention has been given to plant response to increased anthropogenic pressure (Oliveira et al 1994). Consequently, properties of vegetation, including species composition, plant structure, plant biomass, and canopy profile may be used to realize ecosystem inventories giving information on the status and the impact of interactive multistress on natural resources.…”

The relative importance of cork harvesting and climate for stem radial growth of Quercus suber L.

“…Radial stem growth was assessed with a depth micrometer (Series 129-Mitutoyo, MGF Co. Ltd., Tokyo, Japan), measuring the distance between a frame attached to the cork and a lag screw embedded in the wood [7]. Data refer to the south side of the trunk at breast height (1.30 m), and are presented as radial increments (wood plus cork) over March-late June (Spring) and MarchFebruary (annual).…”

“…Data refer to the south side of the trunk at breast height (1.30 m), and are presented as radial increments (wood plus cork) over March-late June (Spring) and MarchFebruary (annual). These periods were defined according to the phenology of this species [7].…”