Within- and among-tree variation in leaf morphology of Q. petraea (Matt.) Liebl. natural populations

Variation in leaf morphology of Quercus petraea in response to several ecological conditions has been studied extensively, although not explicitly in the context of within- and among-tree variation. This study examined leaf morphology and anatomy of Q. petraea, growing in five natural Italian populations adapted to different ecological environments, to understand the pattern of within- and among-tree variation in this species. We used an ANOVA model with both crossed and nested effects. All levels contributed significant components of variation. Within-tree variation due to branch position was large, particularly in thickness and productivity (40%). For 19 of 32 variables, the variation among trees was surprisingly lower than the within-tree variation explained by branch position. Trends in leaf morphology and anatomy with branch position exhibited the sunshade dichotomy. Patterns of crown plasticity showed lower values in the two xeric populations. Results suggest the need for taxonomic studies to consider variation as a quantitative attribute of individual trees.