Abstract
Leaves are the main source of CO2 assimilation in plants. Photosynthetic rates are generally low in young unexpanded leaves, and increase up to full leaf expansion or slightly before/after, the leaves become fully expanded. This phase of leaf development may take several days or weeks, depending on the species. Functional and structural properties of leaves during shoot development in irrigated deciduous fruit trees may differ from those of xeric evergreen shrubs grown as rain fed crops in Mediterranean-type agro-ecosystems. These features of foliage are key factors in productivity since they influence source-sink relationships; the regulation of carbon allocation determine crop yield in plants, though these characteristics have not comprehensively studied in Mediterranean woody plants. Changes in photosynthetic capacity and anatomical properties during leaf development were studied in Olea europaea. In this sclerophyllous species, mechanical protection of mesophyll cells had priority over efficiency of photochemical mechanisms, with respect to deciduous fruit trees. In olive, the relative importance that biomechanical and biochemical leaf traits had on photosynthetic capacity depended on a complex interaction of internal architecture and physiological differences; functional and structural features of leaves ultimately reflected adaptations to environment.