采脂年限对湿地松活立木不同部位材性变化的影响

Effects of Resin-Tapping Year on Wood Properties of Living Pinus elliottii

[目的]通过采脂试验,结合Resistograph技术,研究不同采脂年限对湿地松采脂部位、未采脂部位(树干基部)的基本密度和木质素含量的影响,为湿地松遗传改良和资源最优化利用提供参考。[方法]以采脂8、6、3、0(未采脂)a的20年生湿地松为材料,利用Resistograph测定其采脂部位、树干基部密度的相对值和年轮宽度,在同株同一位置上利用电动生长锥钻取木芯并收集木屑,测定木芯基本密度和木屑木质素含量,分析其与Resistograph测定结果的相关性。[结果]采脂8、6、3、0 a的湿地松木材基本密度与Resistograph测定值的相关系数分别为0.45、0.39、0.50、0.63,分别建立木材阻力预测木材基本密度的线性回归方程。木质素含量与Resistograph测定值相关不显著(P>0.05)。采脂3 a的湿地松树干基部基本密度显著高于采脂8、6、0 a的基本密度,采脂8、6 a的基本密度显著低于未采脂的基本密度,而采脂6 a和采脂8 a的基本密度间无显著性差异;采脂3 a的湿地松采脂部位基本密度显著高于采脂6、0 a的基本密度,但与采脂8 a的无差异,采脂8、6、0 a的基本密度三者之间无显著差异;木质素含量分析结果显示,仅采脂6 a的湿地松采脂部位木质素含量显著低于采脂8、3、0 a的木质素含量,其余均无显著性差异,但采脂6 a的树干基部木质素含量比其它3个采脂年限的木质素含量低。[结论]Resistograph测定同样适用于采脂后湿地松基本密度的预测,但其不可预测木质素含量;一定采脂年限范围内,采脂使湿地松树干基部和采脂部位的基本密度先升高后降低,采脂部位的木质素含量先降低后升高,但对树干基部木质素含量无影响;采脂超过一定年限,可导致采脂部位的基本密度高于树干基部的基本密度,而对两个部位的木质素含量无影响。

[Objective]To study the influnence of resin-tapping duration on the basic density and lignin content of resin-tapping parts and trunk of Pinus elliottii in order to optimize the genetic improvement and resource utilization of P.elliottii.[Method]Twenty-years-old P.elliottii trees that have been resin-tapped for 8,6,3,and 0 years were studied using Resistograph technology to measure the relative value of density and width of tree in the resin-tapping part and the base of the trunk.The wood core was extracted from the same plant by electric growth cone drill and the sawdust was collected.The basic density of wood was determined by submerged water method and the lignin content was determined by Reagent test kit.The correlation around basic density,lignin content and the Resistograph was analyzed.[Result]The correlation coefficients between the basic density of P.elliottii wood and the Resistograph values after 8,6,3 and 0 years of resin-tapping were 0.45,0.39,0.50 and 0.63,respectively.The linear regression equations for predicting the basic density of wood using Resistograph values were established.There was no significant correlation between lignin content and Resistograph values(P>0.05).The base density of the tree trunk of P.elliottii after 3 years of resin-tapping was significantly higher than that after 0,6 and 8 years of resin-tapping,and the base density of the tree trunk after 6 and 8 years of resin-tapping was significantly lower than that of the tree trunk without resin-tapping,but there was no significant difference between the base density of the tree trunk after 6 and 8 years of resin-tapping.The basic density of P.elliottii after 3 years of resin-tapping was significantly higher than that after 0 and 6 years of resin-tapping,but there was no difference with that after 8 years of resin-tapping.There was no significant difference among the basic density after 0,6 and 8 years of resin-tapping.The analysis results of lignin content showed that the lignin content in the base of the tree trunk was lower than that after 0,3 and 8 years of resin-tapping,and there was no significant difference in the rest,but the lignin content in the base of the tree trunk was lower after 6 years of resin-tapping than that after the other three durations.[Conclusion]Resistograph determination is suitable for predicting the basic density of P.elliottii after resin-tapping,but not for lignin content.To a certain extent,the basic density of P.elliottii at the base and site of tree trunk will increase in initial and then decrease,and the lignin content at the site of tree trunk will decrease in initial and then increase,but shows no effect on the lignin content at the base of tree trunk.When the resin is harvested over a certain years,the basic density of the resin-tapping part will be higher than that of the base of tree trunk,but the lignin content of the two parts is not affected.