细叶云南松天然林和人工林的生材性质研究

Green Wood Properties of Pinus yunnanensis var.tenuifolia

为研究细叶云南松天然林和人工林木材生材性质。采用体积法和质量法测定树皮率,排水法测定木材体积,并对测定得到的数据进行分析。结果表明,天然林树皮体积百分率随着树高的增加而减小,树皮质量百分率变异规律不明显;人工林树皮体积百分率和质量百分率随着树高的增加均变化不大。天然林和人工林的树皮体积百分率的均值分别为15.18%和14.73%,树皮质量百分率均值分别为9.25%和11.7%。天然林和人工林心材基本没有形成,心材率平均值分别为1.04%和0.18%。天然林和人工林南北向生材密度从髓心向外逐渐增加,生材密度随着树高增加均呈现较为波动的趋势,天然林和人工林生材密度均值分别为1.022g·cm-3和0.928g·cm-3。天然林南北向的基本密度从髓心向外均逐渐增加,人工林南北向差异较大,南向呈现逐渐减小,而北向先增大后减小。天然林和人工林的基本密度随着树高增加基本无变化。天然林和人工林基本密度的均值分别为0.481g·cm-3和0.472g·cm-3。天然林生材含水率随着树高的增加先增大,再减小的趋势,人工林生材含水率则逐渐增大。天然林南北向的生材含水率从髓心向外逐渐减小;而人工林南北向则逐渐增大。天然林和人工林生材含水率均值分别为119.19%和107.12%。

Properties of the green woods of Pinus yunnanensis var. tenuifolia both from natural forests and plantations were examined. The bark percentage was determined by the volume and the mass methods. The volume was determined by the drainage method. The data obtained were analyzed. The bark volume percentage of natural forests decreased with tree height, and no significant variation regularities were observed. For plantations, the bark volume percentage and bark mass percentage were stable with the in crease of tree height. The averages of bark volume percentage for natural forests and plantations were 15.18% and 14.73%, respectively, while the averages of bark mass percentage were 9.25% and 11.7%, respectively. The heartwoods of natural forests and plantations were not formed basically, and the avera ges of heartwood percentages were only 1.04% and 0.18%, respectively. The changes of green density of south and north increased gradually form the pith to the sapwood, and the density was fluctuated with the increase of tree height. The averages of green density of natural forests and plantations were 1. 022 and 0. 928 g · cm^-3 , respectively. The basic density of south and north of natural forests increased from pith to sapwood gradually. For plantations however, significant differences in basic density were observed： in south direction, it decreased from pith to the sapwood, while in north direction, it increased first, and then decreased. The changes of basic density of natural forests and plantations were not significant, with the averages of 0. 481 g · cm ^-3 and 0. 472 g· cm ^-3, respectively. The moisture content of green woods of natural forests increased first, and then decreased with the tree height. For plantations, it increased gradually with tree height. From pith to sapwood of south and north, the moisture content of natural forests de creased gradually, while it increased for plantations. Averages of moisture content for natural forests and plantations were 119.19% and 107.12%, respectively.