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目前,我区西部,仍然以发展杨树为重点,对于解决缺林少材的困难,具有一定的现实意义。可是,究竟发展哪些树种较好,值得研究。北京杨属速生品种,尤其在幼令,长势喜人,四旁定植的北京杨,十年胸径可达25—30Cm。但是,北京杨材质差、材性脆,而且缺乏弹性,其容积密度(每立方米生长木的干重以 kg 表示)较低,经测定为408kg/m~3;更为严重的是在我区栽植北京溃烂者居多,地
At present, the western part of our region still focuses on the development of poplar and has certain practical significance for solving the difficulties of shortage of forest-less timber. However, what kind of tree species is better developed is worth studying. Beijing poplar is a fast-growing variety, especially in the young, growing, surrounded by Beijing Yang, 10-year DBH up to 25-30Cm. However, Beijing Yang poor material, brittle and brittle material, and the lack of flexibility, the bulk density (dry weight per cubic meter of growth in kg), measured as 408kg / m ~ 3; more serious in me District Beijing fester mostly, to