The variation patterns of tree growth characteristics and wood properties for 18-year-old loblolly pine planted in the southeast of Shandong Province of China were studied. The growth characteristics of two stands were 8.2 m in tree height,15.38 cm in diameter at breast height (DBH) and 0.055 77 m3 in volume. The fast growth period was 2-5 years for tree height increment and 1-9 years for DBH. The intersection of annual and mean increment of volume was at 20-25 years,and the quantitative mature age needed for further determination. The radial variation in wood basic density gradually increased from the pith (0.35-0.37 g/cm3) to the bark and tended to be stable after 8 years (0.44-0.46 g/cm3). The highest hot water extractive content reached 11.2 percent in the pith. The changing ranges of tracheid length, ratios of tracheid length-width, tracheid double wall thickness-diameter and tracheid diameter-width in radial direction were 1 582-3 127μm, 44.7-70.5, 0. 23-0.41 and 0.70-0.81 respectively. Basic density was negatively correlated with the tracheid width, tracheid diameter and ratio of tracheid diameter-width, and positively correlated with tracheid wall thickness and ratio of tracheid double wall thickness-diameter. The annual ring number had significant correlations with tracheid morphological features, late wood percentage, basic density and hot-extractive content at the 0.01 level in the regression analysis,indicating that the tree age was the remarkable influence factor on wood properties. The exotic loblolly pine in the southeast of Shandong Province has high basic density and good tracheid morphological features, which meets the pulpwood requirement and can be used as materials of paper-making. There is fewer commercial tree species suitable for cultivation in this area, so it is a recommended variety due to its rapid growth characteristic.%报道了我国鲁东南引种栽培火炬松18年生人工林生长、材性的变化规律.18年生林分树高为8.2m,胸径为15.38 cm,单株材积均值约为0.05577 m3.树高和胸径的速生期分别为2～5 a、1～9 a,材积连年生长量和平均生长量曲线的交叉点估测在20～25 a后,其数量成熟龄有待进一步确定.基本密度的径向变化由髓心处(0.35～0.37g/cm3)向外逐年增加,第8年后趋于稳定(0.44～0.46g/cm3).髓心处热水浸提物质量分数最高,可达11.2%.管胞长度、长宽比、壁腔比、腔径比变化范围分别为1 582～3 127 μm、44.7～70.5、0.23～0.41、0.70～0.81.基本密度与管胞宽度、腔径、腔径比多呈负相关,与双壁厚、壁腔比呈正相关,管胞形态特征值、晚材率、基本密度、浸提物质量分数与生长轮回归分析,均在F0.01水平上显著,表明树龄是材性的主要影响因子.该区引种栽培火炬松木材密度数值较大,管胞形态特征数值好,适宜造纸.该区适宜栽培的用材树种少,火炬松表现出典型的速生特性,材质好,是值得推广的用材树种.
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