Морфологічні ознаки та стан фотосинтетичного апарату листків Acer platanoides і A. tataricum з різних рівнів крони

Abstract

For forest-grown trees of two Acer species (A. platanoides, shade-tolerant, and A. tataricum, moderately shade-tolerant), we studied 13 morphological and 5 photochemical foliage traits across two crown locations (bottom and top). The comparison of the species indicates that the specific leaf mass, specific leaf area, specific water content, stomatal density, stomatal area, and stomatal width respond to the leaf crown location in a similar manner in both species, and the intracrown plasticity is statistically indistinguishable across both species for the leaf area and petiole length. Chlorophyll fluorescence traits (F′v/F′m, qP, qN, ø PSII) in leaves from the bottom and top of crowns are similar in both species under lower photon flux densities (40 and 180 μmol mˉ²sˉ¹). The more effective functioning of the photosynthetic apparatus in the moderately shade-tolerant species as compared to the shade-tolerant one is found at higher photon flux densities (350 and 700 μmol mˉ²sˉ¹) that suggests a higher resistan to photoinhibition in A. tataricum foliage.