南方型黑杨无性系木材材性的研究

在48个7—8年生南方型黑杨无性系对比试验林中，选择生长量达中等以上水平的19个新、老无性系，开展木材基本密度、纤维素含量、纤维形态的分析研究。纤维素含量和纤维长度在19个无性系中无显著差异，基本密度只在中汉17等几个无性系间有显著差异。基本密度和纤维长度在不同年龄间都存在显著差异。1～3年生的纤维长度在0．9mm以下，属短纤维；4—7年生的纤维长度在0．91mm以上，达到中级纤维长度标准。因此，杨树纸浆材超短轮伐期可以确定为3a或3a以上。

Study on the wood characteristics of southern Populus nigra clone species

Analysis of basic wood density, cellulose content, fiber form of 19 new and elder clone species, which growth above the average growth level in 48 southern Populus nigra clone species constructive experiment forest seven to eight years old. There was no increase in wood cellulose content and fiber length of 19 clone species. There was evidence of wood? density increase among the Zhonghan 17 species. There was evidence in the basic density and fiber length in different ages of Populus nigra. The fiber length was increase with the age of one to eight years old Populus. The length of 0.9mm during one to three years old Populus called short fiber, and the evidence in each year after growth four years. The length above 0.91mm during four to seven years old Populus and reached the average fiber length, and there was no evidence each year. So the super short alternate cutting of Populus pulpwood was three or above three years.