Leaf Geometric morphometrics among a natural population of Norway maple (Acer platanoidesL.) in Northern Algeria

Abstract

Maple (Acer L.) is a diverse tree genera that includes more than a hundred of deciduous and evergreen species in Northern hemisphere,Acer platanoidesis a species from the maple’s genuswith an invasive aptitudes in Europe and North America,this specieshad never been recordedin North Africa andthe main aim of this work is to investigate the shape and size variability withina natural population in Northern Algeria. The study was carried out using a collection of multivariate, bivariate and univariate statistics, 303 A. platanoides leaves were includedin the analysis counting 2 taxa from8 countries. The analyzed data showssome very close results between Algerian and European A. platanoides, One Way ANOVA of size provided a significant p.value<0.001 between the three studied populations, the Bonferroni correction doesn’t show any significant p.values between Algerian and European A.platanoides but confirmed the difference of A. platanoidesssp turkestanicum from the others, linear regression of shape and size shows a significant p.value of <0.001 but a low negative coefficient of correlation r= -0.18 and a low coefficient of determination r2= 0.033, Principal component analysis (PCA)shows an inertia of 53.48% between the first two components and revealed three different forms, MANOVA based on shape data revealed a significant p.value <0.001 between groups of taxa, a Pillai trace of 1.108, and a Wilks lambda coefficient of 0.192, the closest squared Mahalanobis distance (d=8.01) was reported between Algerian and European A. platanoidespopulations while the largest (d=16.74) was scored between Algerian and Iranian populations, clustering using Kmeans was depending on both Elbow and Silhouette methods, the typical number of clusters according to the two methods was k=2,however, clustering doesn’t reveal any specific shape or group of leaves, the statistical analysis proved a small phenotypic plasticity between Algerian and European A. platanoidesleaves in terms of shape while size remain conserved between both populations, the provided statistical tools confirms the ability of A. platanoidestoshow an environmental adaptation additionally also approves A. platanoidessspturkestanicumas distinguished subspecies.