Mirzeta Memisevic Hodzic, Azra Čabaravdić, Dalibor Ballian
Phenotypic variation in leaf and acorn traits in natural populations of Quercus petraea
Dendrobiology 2025, vol. 94: 100-114
https://doi.org/10.12657/denbio.094.007
Abstract:
Background Quercus petraea (Matt.) Liebl. holds significant ecological and economic value, yet phenotypic variation within its natural populations remains only partially explored. The main objectives of the study were: (1) to quantify the phenotypic variation in the analyzed leaf and acorn traits; (2) to determine the proportion of phenotypic variation occurring among and within populations; (3) to examine the pattern of population-level variation and its relationship with bioclimatic factors. Material and methods A total of 13 leaf traits and 10 acorn traits were analyzed in 64 sampled trees from seven natural populations. Descriptive statistics and population differentiation coefficients were calculated. The significance of differences in traits mean among populations and among trees within populations were assessed. Principal component analysis (PCA) was conducted at both the tree and population levels. Correlations between morphological principal components and bioclimatic variables were examined, and regression models were developed to evaluate relationships between significantly correlated morphological traits and bioclimatic factors. Results The coefficients of variation for the 23 traits ranged widely, from 12.08% for cupule width to 36.61% for petiole length, with an average of 20.36%. Nested ANOVA revealed substantial phenotypic variations both within and among populations. The primary source of variation was at the intra-population level, accounting for an average of 68.25%, which exceeded the inter-population variation (30.34%). The analyzed traits were reduced to six principal components, which together explained 88% of the phenotypic variation among trees. A statistically significant correlation between morphological principal components and bioclimatic variables was found for the first component, specifically with temperature related variables. Conclusions The study confirms that Q. petraea in Bosnia and Herzegovina exhibits considerable morphological variability, primarily within populations, and that leaf traits are strongly influenced by climatic gradients. Conservation strategies should prioritize the preservation of population integrity and patterns of local adaptation patterns, particularly in ecologically marginal or historically disturbed sites.
Keywords: Quercus petraea, natural population, variability, morphological traits