| 摘要: |
| 【 目的】阐明不同苗龄云南松幼苗的遮阴适应机制，为龄级化造林及林木环境适应理论提供参考。 【方法】以1年生和3年生云南松幼苗为试验材料，在100%，80%，45%，30%和5%全光照共5个光照梯度下进行遮阴 试验。利用表型可塑性指数及相关性分析和主成分分析，评估不同苗龄云南松幼苗针叶叶绿素含量、非结构性碳水化 合物（NSC）和碳氮磷化学计量特征。【 结果】与CK相比，1年生云南松幼苗在轻度遮阴（80%全光照，L1）处理下光合色素（Chl a、Chl b）及NSC含量显著升高，但在重度遮阴（5%全光照，L4）下，碳富集导致C/P比值升高19.86%，生长主要受限于N（N/P<14）。与CK相比，3年生云南松幼苗在遮阴下通过光合效率优化（Ch（l a+b）提高29.78%）和磷吸收增强（P含量增加15.56%），实现NSC的积累（可溶性糖含量较1年生云南松幼苗提高44.95%）与碳氮协同调控 （C/N降幅49.33%），显著缓解养分限制。表型可塑性分析结果表明，3年生云南松幼苗的光合色素、NSC及N利用等表型可塑性指数（0.13~0.70）显著高于1年生云南松幼苗（0.05~0.63）。【 结论】云南松幼苗的遮阴适应策略存在苗 龄差异，1年生云南松幼苗通过调节光合色素和短期碳分配来维持代谢平衡，3年生云南松幼苗通过增强磷吸收效率 和长期碳储存来优化资源分配。建议在云南松人工林管理中，针对其低龄幼苗维持 30%~80% 全光照以平衡碳代谢， 其高龄幼苗则通过补充磷素来提高遮阴耐受性。 |
| 关键词: 云南松 遮阴 非结构性碳水化合物 碳氮磷化学计量特征 森林培育 |
| DOI：10. 13207/j. jnwafu. 2026. 06. 003 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31960306） |
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| Effects of shading on non⁃structural carbohydrates and chemical metrological characteristics of carbon，nitrogen and phosphorus in needles of young Pinus yunnanensis seedlings |
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ZHU Weisong, LIU Yuanxi, DUAN Guihe, CHEN Jialan, WU Junwen
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College of Forestry，Southwest Forestry University，Kunming，Yunnan 650224，China
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| Abstract: |
| 【 Objective】The study aims to elucidate the shading adaptation mechanism of Pinus yunnanensis seedlings at different ages，to provide a reference for age-class silviculture and forest environmental adaptation theory.【Method】One-year-old and three-year-old Pinus yunnanensis seedlings were used to conduct the shade test with five light gradients（100%，80%，45%，30% and 5% full light）. Phenotypic plasticity index，correlation analysis and principal component analysis were used to assess the chlorophyll content，non-structural carbohydrates（NSC），and carbon，nitrogen and phosphorus stoichiometric characteristics of needles from Pinus yunnanensis seedlings of different ages.【Result】Compared with CK，photosynthetic pigments（Chl a，Chl b） and NSC contents were significantly higher in one-year-old Pinus yunnanensis seedlings under light shade（80% full light，L1） treatment. Under heavy shade（5% full light，L4），however，carbon enrichment resulted in a 19.86% increase in the C/P ratio，and the seedling growth was mainly limited by N（N/P<14）. Compared with CK，3-year-old Pinus yunnanensis seedlings under shade significantly alleviated nutrient limitation through optimization of photosynthetic efficiency （29.78% increase in Chl（a+b）） and enhancement of phosphorus uptake （15.56% increase in P content），which resulted in the accumulation of NSC（44.95% increase in soluble sugar content compared with one-year-old Pinus yunnanensis） and the synergistic regulation of carbon and nitrogen （49.33% decrease in C/N）. The results of phenotypic plasticity analysis showed that the plasticity indices of
photosynthetic pigments，NSC and N utilization of 3-year-old Pinus yunnanensis seedlings（0.13-0.70） were significantly higher than those of one-year-old Pinus yunnanensis seedlings（0.05-0.63）.【Conclusion】Shade
adaptation strategies for Pinus yunnanensis seedlings differed according to seedling age，with one-year-old Pinus yunnanensis seedlings maintaining metabolic balance by regulating photosynthetic pigments and short-term car-bon allocation，and three-year-old Pinus yunnanensis seedlings optimizing resource allocation by enhancing phosphorus uptake efficiency and long-term carbon storage. It is suggested that in Pinus yunnanensis plantation forest
management，30%-80% full light condition should be maintained to balance carbon metabolism in younger seedlings，and phosphorus supplementation should be used to improve the shade tolerance of older seedlings. |
| Key words: Pinus yunnanensis shade nonstructural carbohydrates carbon,nitrogen and phosphorus stoi⁃ chiometric characteristics forest cultivation |
