| 摘要: |
| 【目的】研究平茬后云南松苗木的生物量分配特征及其相对生长关系，为综合分析其平茬后的补偿性生长提供理论基础。【方法】以1年生云南松容器苗为试验材料，设置重度平茬（平茬高度5 cm）、中度平茬（平茬高度10 cm）和轻度平茬（平茬高度15 cm）3个平茬高度处理，以不平茬作为对照，1年后采用全株收获法测定根（主根和侧根）、茎（主干、侧枝、萌条枝）、叶（母株针叶和萌条针叶）生物量，并计算各器官的生物量占比，比较分析各处理不同器官生物量分配的差异及平茬高度与各器官生物量间的相关性；采用异速生长方程分析各器官间生物量的相对生长关系。【结果】 云南松苗木除重度平茬的叶生物量显著（P＜0.05）小于对照外，其余不同平茬高度处理间根、茎、叶、地上部分和单株生物量均无显著差异（P＞0.05）；不同平茬高度处理间根、茎、叶生物量的再分配存在明显差异，表现为随着平茬高度的降低，根生物量更多地分配到主根，茎生物量更多分配到侧枝，叶生物量更多分配到母株针叶。从生物量占比来看，处理间根质比、叶质比存在明显差异，与对照相比，重度平茬可显著提高根质比、降低叶质比（P＜0.05）；随着平茬高度的降低，云南松苗木根质比（16.38%～23.52%）逐渐增加，叶质比（48.12%～40.94%）逐渐减小，茎质比（33.79%～35.54%）的变化较小。相关性分析表明，平茬高度与主根生物量、侧枝生物量呈显著负相关（P＜0.05），与萌条枝生物量呈显著正相关，与萌条针叶生物量呈极显著正相关（P＜0.01），即平茬高度的降低有利于主根生物量和侧枝生物量的积累，但会减少萌条枝和萌条针叶生物量。相对生长关系分析表明，重度平茬叶 单株生物量间和轻度平茬地上部分 单株生物量间为异速生长关系；其余的叶-茎、叶-根、茎-根、地上部分-根生物量等的相对生长关系均为等速生长。【结论】平茬通过影响云南松苗木器官间的相对生长关系进而影响生物量在各器官间的分配；平茬高度降低可促进生物量向根分配，减少向叶分配，而对茎生物量分配无显著影响；平茬后的云南松苗木生物量分配策略在一定程度上支持最优分配假说。 |
| 关键词: 云南松 平茬 生物量分配 森林培育 |
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| 基金项目:国家自然科学基金项目（31760204,31860203）;云南省万人计划青年拔尖人才项目（09901-80201441） |
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| Effects of stumping treatments on biomass allocation patterns and relative growth relationships of Pinus yunnanensis Franch. seedlings |
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CAI Nianhui,TANG Junrong,CHE Fengxian,et al
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| Abstract: |
| 【Objective】This paper studied the biomass allocation patterns and relative growth relationships of Pinus yunnanensis Franch. seedlings after stumping to provide theoretical basis for the comprehensive analyses of compensation growth.【Method】In this study,one year old container seedlings of P. yunnanensis were selected for treatments with different stumping intensities of heavy,moderate and light (stumping heights were 5 cm,10 cm and 15 cm,respectively) and seedlings without stumping were used as control.After one year,the whole harvest method was used to determine biomass of root (main root and lateral root),stem (trunk,branch,sprout branch),and needle (mother plant needle and sprout needle).The biomass ratios of different organs were calculated and the distribution differences of different organs in different treatments were compared.The relationships between stumping height and biomass were analyzed,and the relative growth relationships were obtained using allometric growth equation.【Result】There were insignificant differences between root,stem,needle,aboveground and individual plant biomass of P. yunnanensis seedlings in different stumping heights except that needle biomass accumulation of heavy stumping was significantly less than that of the control (P＜0.05).Biomass redistribution in root,stem and leaf for different stumping heights had significant differences.The root biomass allocation was prior to main root,stem biomass allocation was prior to branch,and needle biomass allocation was prior to sprout needle with the decrease of stumping height.There were significant differences among treatments in root biomass ratios and needle biomass ratios.Heavy stumping significantly increased root biomass ratio,while significantly reduced needle biomass ratio (P＜0.05) compared with the control.With the decrease of stumping height,root biomass ratios of P. yunnanensis seedlings (16.38%-23.52%) increased gradually,needle biomass ratios (48.12%-40.94%) decreased,while stem biomass ratios (33.79%-35.54%) varied lightly.Correlation analyses showed that stumping height had significant negative correlation with root biomass and branch biomass (P＜0.05),and significantly positive correlation with sprout branch (P＜0.05) and sprout needle (P＜0.01).The decrease of stumping height was helpful for accumulation of root biomass and branch biomass,but it was adverse for accumulation of sprout branch biomass and sprout needle biomass.There was an allometric growth relationship between needle and individual plant biomass in heavy stumping treatment and between aboveground and individual plant biomass in light stumping treatment.The relative growth relationships between needle-stem,needle-root,stem-root,and aboveground-root were constant growth.【Conclusion】Biomass allocation in different organs of P. yunnanensis seedlings after stumping was affected by influencing relative growth of organs.Reducing stumping height accelerated root biomass allocation,reduced needle biomass allocation,and insignificantly changed stem biomass allocation.The biomass allocation of P. yunnanensis seedling supported the optimal distribution hypothesis. |
| Key words: Pinus yunnanensis Franch. stumping biomass allocation ferest cultivation |
