FOLIAR PLASTICITY IN <em>SCHINUS</em> <em>TEREBINTHIFOLIA</em> (ANACARDIACEAE), A TROPICAL/SUBTROPICAL SPECIES COMMONLY USED IN REVEGETATION PROGRAMMES

Abstract

The study aimed to assess the influence of light on structural aspects of Schinus terebinthifolia sun and shade leaves. At the morphological level, leaf length, width, area and dry mass were measured. Anatomical analysis assessed the thickness and area of leaf blade and leaf tissues, histolocalised lipids and phenols, and calculated stomatal index. Sun leaves showed lower number of leaflets (22%) and lower leaf (50%) and leaflet area (30%). Petiole length and width were respectively 34 and 33% higher in shade leaves. Tissue proportion, stomatal index and stomatal density showed no variation between morphotypes. However, epidermal periclinal outer-wall thickness in sun leaflets was higher on both the adaxial (24%) and abaxial (27%) leaf surfaces, as was the total adaxial (11%) and abaxial (23%) epidermal thickness. Analogously, palisade and spongy parenchyma thicknesses were higher in sun leaflets (62 and 45%, respectively). Histochemical reaction for phenol detection was stronger in sun leaves. Schinus terebinthifolia showed high foliar phenotypic plasticity in response to different light conditions that occur even on a single-individual basis, across different crown regions.