Poplar Clones Trial for three year short rotation system

Poplars are one of the tree species with high potential for producing large amount of wood at short period due to their fast growth ability. Because of their wood special and unique characteristics, they can be used in different industries such as particleboard, pulp, paper, match board. The aim of this study was to increase wood production in each area unit, produce wood continuosly at short rotation system and increase income of poplar growers. Overall, 18 native and exotic clones of poplar were investigated at three year rotation system and repeated for the same rotation period. The research was conducted under statistical design of Randomized complete Blocks with three replicates at Alborz - Karaj Research Centre. After each rotation period few tree parameters including survival%, shoot numbers, number of shoots having more than 2 m. height, diameter of vigorous shoots at stem collar and intemediate levels, height and shoot dry weight were measured. Statistical analysis of the two rotation periods showed that there were significant difference between the poplar clones for their yield per hectare. The clones P.e. 561.41, P.e. triplo and P.e. costanzo had the greatest dry biomass production (25.43, 25.22 and 22.65 ton/ha/yr, respectively). It can be concluded that increasing the trees space and rotation period, selecting the vigorous trees and prunning the extra shoots, result in high diameter growth and high pulp and paper production of the most out standing clones.