鹅掌楸主要木材性状早期选择可行性研究(英文)

STUDY ON FEASIBILITY OF EARLIER SELECTION OF MAIN WOOD CHARACTERISTICS IN LIRIODENDRON CHINENSE

邻近江西分宜种源试验林 ,选择一片完整的鹅掌楸 (Liriodendronchinense)近成熟人工林 (1981年栽植 ) ,抽取 33棵样本株 ,分年轮测定了木材基本密度和纤维长度。鹅掌楸木材基本密度径向变异模式呈“V”曲线 ,纤维长度径向变异遵从指数曲线模式 ,研究结果与Harold和Taylor等人关于北美鹅掌楸木材性状径向变异的描述基本一致。幼成龄年 -年相关分析结果表明 ,当大于等于 5个胸高处年轮时 (约相当于树龄 7a生 ) ,两性状幼成龄材相关均显著。利用鹅掌楸 15个 7a生种源材性数据平均值与 17a生人工林材性数据的前 5个年轮段数据 ,进行比较与拟合 ,2组数据在共有时段内成线性关系 ,且回归系数B1 均接近于 1,变化趋势基本平行 ,分析结果表明鹅掌楸幼成龄变异规律从整体上来说存在可比性 ,其材性早期选择是可行的。探讨了平均龄龄相关系数 (MACC)随年龄间隔 (AI)的变异趋势 :两性状MACC与年龄间隔成反比 ,即年龄间隔越大MACC越小 ,这可能源于基因表达的时间控制理论 ,这种变化关系在其他的树种研究中也被提到过。该分析结果从另一侧面阐明了鹅掌楸主要木材性状的早期选择是可行的 ,但选择年龄不宜小于

Thirty three trees from a seventeen years old plantation of Chinese tulip tree (Liriodendron chinense ) in Fenyi county, Jiangxi Province were randomly selected, and their basic density, and fiber length of each growth ring for the increment core samples at breast height were measured. The results showed that the radial pattern appeared a “V” type curve for basic density and an exponential one for fiber length. Age\|age correlation analysis showed the earlier selection for basic density and fiber length was at a cambial age not younger than 5 at the breast height. Compared with provenance trials with 15 sevenyears old provenances, analysis results showed that the radial pattern curves were basically parallel for both seven\|year\|old and seventeen\|year\|old plantations, and indicated the earlier selection was also applicable(α=0.05) for the provenance trials. Finally, the variation trend of mean age\|age correlation coefficients (MACC) with age interval was discussed. MACC of both basic density and fiber length in L. chinense decreased with the increase of age interval value although the decreasing rate of basic density was more violent. According to the MACC analysis, the result also suggested that it was feasible for earlier selection of the two main wood characteristics, but earlier selection would be more reliable when the plantation age is older than seven years old in practice.