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报道了马尾松木材管胞长度、管胞长宽比、基本密度和化学组分含量的变异规律。结合林木材积连年生长量给出了不同树龄材性的具体数值。管胞长度径向变异遵循“递增、趋于稳定”模式，纵向变异由基部向上先递增至７．３ｍ高度，而后递减至１９．３ｍ；管胞长宽比变异与管胞长度变化趋势一致。基本密度髓心附近较大，由髓心向外递减至最小值后再缓慢增加，并趋于稳定；基本密度纵向变异由基部向上递减，最大值位于树干基部。纤维素含量由髓心附近的３８．７５％（１～３轮）递增到２２轮处的４８．９８％，净增１０．４１％；木素、多缩戊糖和苯醇抽出物含量分别由髓心附近的２８．３５％，１４．３２％和６．６％递减到树皮附近的２４．７％，１０．２４％和１．２２％，３者依次净减３．６５％，４．０８％和５．３８％。马尾松木材幼龄期约１４～１８ａ，幼龄期前天然林管胞长度、长宽比和浸提后的基本密度大于人工林，幼龄期后则正好相反。基于不同树龄材性的变化，马尾松短周期纸浆林最低采伐林龄不得低于１５ａ。
The variation rules of Pinus massoniana wood tracheid length, tracheid length-width ratio, basic density and chemical composition were reported. Combined with the annual growth of timber volume gives the specific value of different age timber. The radial variation of tracheid length follows the pattern of “increasing and stabilizing”. The longitudinal variation increases from the base to the height of 7.3 m first and then decreases to 19.3 m. The variation of tracheid length-width ratio is consistent with that of tracheid length. The density of the basic density is larger near the medulla, decreases slowly from the medullary center to the minimum and then slowly increases, and tends to be stable. The longitudinal variation of the basic density decreases gradually from the base and the maximum is located at the base of the trunk. The content of cellulose increased from 38.75% (1 ~ 3 rounds) near the pulp center to 48.98% at 22 rounds, a net increase of 10.41%. The content of lignin, Decreased from 28.35%, 14.32% and 6.6% in the vicinity of the medulla to 24.7%, 10.24% and 1.22% in the vicinity of the bark, respectively, with a net decrease of 3.65% 4.08% and 5.38%. The Pinus massoniana wood is about 14-18 years old. Before the young age, the length, aspect ratio and basic density of natural forest were larger than that of the plantation, while the opposite was true after the young age. Based on the changes of different age materials, the minimum cutting age of short-period pulp plantations of masson pine should not be less than 15 years.