تعیین ارقام مناسب صنوبر در سیستم بهره برداری کوتاه مدت در چمستان (نور)

Research plan of short rotation system was executed in three terms (2-3-4 years old) in Chamestan. This plan begined with planting of cuttings of 15 clones. Then, All of shoots were cutted of bottom after the first growth year in order to monotony and increasing of growth. In the End terms, All of stems and shoots were remvoed and weighted wet wood production and dry biomass after the 6 months. Since, were cultivated 15 clones of p.deltoides, p.euramericana, p.nigra in this plan, therefore after measuring were investigated parameters such as, percentage survival, number of shoots per seedling, number of shoots over 2 meters, height and diameter means of shoots, resistance to pests and diseases. In the ends of execution terms, clones of poplar were compared from point of view survival, growth and dry wood matter productivity per hectar. Also, Results were analyzed on basis of randomized Complete block design. so, clone of p. d 69/55 produced 20 tones dry matter per hectar per year that is maximum productivity in two years old. clones of p. euramericana triplo and p. deltoides 73/51 produced 17.52 tones and 17.19 tones per hectar per year. P.deltoides 77/51 yielded 16.70 tones per hectare per year in the term of 3 years old. P.euramericana triplo and p. deltoides 69/55 produced 15.75 tones and 14.73 tones per hectar per year. In four years old term, for p. deltoides 69/55 obtined 19 tones dry wood matter productivity and p.deltoides 77/51, p. euramericana triplo produced 17.77 tones and 16.96 tones per hectar. Also, there are significant different among clones from point of view dry wood matter productivity in even three terms.