Analyzing Population Diversity of Common Hornbeam (<i> Carpinus</i><i> betulus</i> L.) in Native Habitats in Turkiye: A Focus on Leaf Characteristics

The primary aim of this investigation was to examine the morphological diversity of leaves in naturally occurring populations of common hornbeam ( Carpinus betulus L.) in T & uuml;rkiye. Twelve common hornbeam populations, distributed over four distinct watersheds in the Eastern Black Sea Region, were sampled from three altitude levels, ranging from sea level to 1200 meters. Nine morphological characteristics of the leaves were analyzed biometrically. We found a high degree of phenotypic heterogeneity both within and among the investigated populations. The eco-geographic principle's classification of populations was disclosed. Altitude appeared to be the primary factor influencing variation in the majority of leaf attributes from the Caml & imath;hem & scedil;in, & Ccedil;aykara, and Espiye watersheds. Compared to trees at lower altitude, trees at higher altitudes were characterized by smaller leaves. The populations in the Trabzon-Ma & ccedil;ka watershed, however, did not show this trend. Largest leaves were observed for trees from the Trabzon-Ma & ccedil;ka watershed region at the second altitude level. Overall, our findings support the notion that the Eastern Black Sea area is a hotspot of biodiversity and that the intricate evolutionary process leading to leaf morphological variability may be a consequence of adaptation and plasticity.