油松侧枝的节间特征及其变异规律

【目的】为阐明油松侧枝的节间特征及其变异规律,了解当年生节间枝条和针叶的异速生长关系,揭示侧枝空间构型、活力和光合产物分配的主要影响因子。【方法】本研究在35 a生油松林内选取了5株标准木的标准枝,通过枝条解析截取了372个节间,采用统计分析和模型模拟等方法对相关问题进行了研究。【结果】结果表明:油松枝条多分为3级,近90%的节间分布在2级和3级枝,直径生长周期为1~4 a、具有针叶着生和光合功能的节间占节间总数的83%;节间直径和长度均随枝级增加而显著下降,均随节间生长周期(或形成时间)的增加而显著增加,后者在枝级间及枝级内的变异均远高于前者,后者受枝级和着生位置光照环境的影响明显高于前者。全枝70%以上的枝条生物量分布在1级枝节间,80%以上的针叶分布在2级和3级枝节间;1级和2级枝的生物量以枝条为主,3级枝以针叶为主。直径生长周期为1~3 a的节间生物量以叶为主,4 a的以枝条为主,4 a以上的以完全以枝条为主。当年生节间的不同特征变量间均成显著的异速生长关系,而非成比例变化。【结论】节间是侧枝的基本单元,其数量、质量、生长发育及其在不同枝级和形成时间的变异,以及其主要构件的异速生长关系是影响侧枝空间构型、活力和光合产物分配的主要因子。

The Internodes Characteristics and Its Variation of Lateral Branches of Pinus tabulaeformis

【Objective】This paper aims to clarify the internodes characteristics and variation of the lateral branches of Pinus tabulaeformis,and to understand the allometric growth relationship between the branch and needle of the current year internodes,and to reveal the major influencing factors of the spatial configuration,vitality,and photosynthetic product distribution of lateral branche.【Method】Five standard branches of standard trees in 35-year-old Pinus tabulaeformis forest were selected to cut into 372 internodes.Related issues were studied by applying statistical analysis and model simulation.【Result】The results showed that Pinus tabulaeformis branches were mostly divided into three levels,and nearly 90%of internodes distributed in the second and third level branches,internodes with 1-4 year diameter growth period and with needle leaves and photosynthetic function accounted for 83%of the total number of internodes,the diameter and length of the internodes decreased significantly with the increase of the branch level,and increased significantly with the increase of the diameter growth period(or formation time),the internodes length variation between branch levels and within levels were much higher than diameter,the former was significantly more affected by the light environment and branch level than the latter,more than 70%of the biomass of the whole branch was distributed to the first-level branches,and more than 80%of the needles biomass was distributed to the second and third-level branches,the biomass of the first and second-level branches was mainly from branches,and the biomass of third-level branches was mainly from needle leaves.The internodes biomass with a diameter growth period of 1-3 years was mainly leaves,4 years was mainly branches,and more than 4 years was completely branches.There was a significant allometric growth relationship among the different characteristic variables of the current internodes,rather than proportional changes.【Conclusion】Internodes are the basic units of lateral branches,their quantity,quality,growth and their variation at different branch levels and different formation time,and the allometric growth relationship of their main components are the main factors affecting the spatial configuration,vitality and photosynthetic product distribution of lateral branch.