BIOECOLOGICAL ADAPTATION, INTRODUCTION ASSESSMENT AND ORNAMENTAL VALUE OF SELECTED INTRODUCED CONIFEROUS TREE SPECIES

Abstract

This study evaluates the bioecological adaptation, environmental tolerance, integrated introduction potential, and ornamental performance of six introduced coniferous tree species cultivated in the Turkistan mountain range during 2022-2024. The study considered cold and heat tolerance, response to light, annual shoot lignification, disease and pest resistance, crown-form retention, branching and shoot-growth capacity, generative development, natural regeneration, and seasonal ornamental value. All six species showed high cold tolerance and no visible disease or pest damage. Heat tolerance differed among taxa: Scots pine, Crimean pine, Siberian stone pine, and Siberian larch tolerated 54-57 °C, whereas Norway spruce and Schrenk spruce showed intermediate tolerance at about 52-53 °C. The integrated assessment reported the highest scores for Siberian stone pine (95 points), Scots pine (92), and Crimean pine (92), followed by Siberian larch (82) and the two spruce taxa (64 each). Seasonal ornamental scores exceeded 500 points in five species, while Siberian larch had the lowest annual decorative score because of autumn-winter needle shedding.