Morphological Variation in Cone and Needle Characteristics of Black Pine (Pinus nigra J.F. Arnold) Under Different Topographic Conditions

Abstract

Potential global warming impact makes it important to study the morphological response of plants under stress conditions. The ability of trees to survive and adapt to possible scenarios can be understood in detail thanks to this awareness. This study investigated the variation in needle and cone morphology of black pine trees growing in different altitudes and aspects (slope surface) within the Western Black Sea region of Türkiye. The research material consisted of 1560 needle and 1560 cone samples from 78 destructively sampled adult black pines growing in six forest stands of varying altitude and aspect. Altitude and aspect were found to be significant in influencing all investigated morphological characteristics including needle length (nl), needle width (nw), needle thickness (nt), sheath length (sl), cone length (cl), cone width (cw), and cw/cl ratio. The most obvious variation between morphological features was found in the cw as a function of altitude, with cones becoming wider as altitude increased. In addition, the morphological diversity of needles and cones due to aspect effect is more common at lower altitudes where there is a greater water deficit. Morphological variation was found to be higher in south-facing slopes where water stress is higher.