Yaroshchuk R. Silvicultural and ecological features of the reproduction and growth of Pseudotsuga menziesii (Mirb.) Franco in plantations of the Western Forest-Steppe zone of Ukraine

Object of study - Douglas fir pure and mixed artificial forest plantations in the Western Forest-Steppe zone of Ukraine. Purpose - to establish the spreading features, vital status and the growth of Douglas fir forest plantations, to characterized seed production features, the natural regeneration course of introduced species in the Western Forest-Steppe zone of Ukraine. Research methods - silvicultural and valuation methods, laboratory analysis, exploratory method, variation statistics. Scientific novelty. The Douglas fir reproductive potential in the region has been determined for the first time. The diethyl sulfate at concentrations 0,3 and 0,6 %, stimulates the introduced species seedlings growth. The dimethyl sulfate at concentrations 0,1, 0,2, 0,4, and 0,8 % inhibits the introduced species seedlings growth. The species vital status in the Western Forest-Steppe zone of Ukraine forest plantations has been established. Practical significance. The reproductive potential determination enables to organize the expanded procurement of forest seed raw materials and to organize the introduced species planting material mass cultivation. The determined terms of the forest seeds raw materials procurement and an optimal seeding rate enable to optimize the valuable species seeds using for the planting material growing. A regional Douglas fir trunk volumes tables have been composed. It permites more accurately determine the growing tree trunk volume during scientific research and the forest management. Field of application: forestry.