南京林业大学学报(自然科学版) ›› 2022, Vol. 46 ›› Issue (3): 74-82.doi: 10.12302/j.issn.1000-2006.202008002

• 研究论文 • 上一篇    下一篇

遮阴条件下杉木幼苗生长和C、N、P化学计量特征的变化

刘青青1(), 黄智军1, 马祥庆1, 王正宁1, 邢先双2, 刘博1,3,*()   

  1. 1.福建农林大学林学院,国家林业和草原局杉木工程技术研究中心,福建 福州 350002
    2.山东省水文中心,山东 济南 250002
    3.曲阜师范大学生命科学学院,山东 曲阜 273165
  • 收稿日期:2020-08-02 接受日期:2021-10-14 出版日期:2022-05-30 发布日期:2022-06-10
  • 通讯作者: 刘博
  • 基金资助:
    国家自然科学基金项目(31670714);国家自然科学基金项目(31570448)

Changes of seedling growth and C、N、P stoichiometric characteristics in Chinese fir under shading

LIU Qingqing1(), HUANG Zhijun1, MA Xiangqing1, WANG Zhengning1, XING Xianshuang2, LIU Bo1,3,*()   

  1. 1. College of Forestry, Fujian Agriculture and Forestry University, Chinese Fir Engineering Technology Research Center, National Forestry and Grassland Administration, Fuzhou 350002, China
    2. Shandong Hydrological Center, Ji’nan 250002, China
    3. College of Life Sciences, Qufu Normal University, Qufu, 273165, China
  • Received:2020-08-02 Accepted:2021-10-14 Online:2022-05-30 Published:2022-06-10
  • Contact: LIU Bo

摘要:

【目的】比较不同强度遮阴条件下杉木(Cunninghamia lanceolata)幼苗生长、生物量积累与分配,以及不同器官碳(C)、氮(N)、磷(P)积累、分配及化学计量特征的差异,探讨杉木幼苗在不同遮阴条件下的C、N、P元素积累及分配的响应策略,揭示遮阴处理对杉木幼苗C、N、P元素变化规律的影响,为杉木苗木繁育、林分光照环境调控管理等提供参考。【方法】选取当年生杉木幼苗为研究对象,通过人工遮阴方式设置5个遮阴梯度,即0%(对照,不遮阴)、遮阴强度40%(透光率60%)、60%(透光率40%)、85%(透光率15%)和95%(透光率5%),持续观测1 a。试验结束后测定幼苗株高与地径增量、各器官生物量、根冠比、各器官C、N、P含量、积累量,并分析C、N、P化学计量特征(以C/N、C/P,N/P表示元素质量比)等指标。【结果】①随遮阴强度的增大,杉木幼苗株高增量总体呈现上升趋势,而地径增量则显著降低(P<0.05)。根、茎、叶及总生物量、根生物量占比和根冠比降低,茎、叶生物量比增大;②根、茎、叶中及总的C、N、P积累量随遮阴强度的增大而降低。随着遮阴强度的增大,杉木地上部分(茎和叶)C和N分配比例增加,而地下部分(根)C和N分配比例则降低。③杉木幼苗C/N和C/P变化趋势相同,随着遮阴强度的增大先增加后减少。杉木幼苗各器官N/P低于14,表明杉木幼苗在不同遮阴下的生长受到N限制。【结论】杉木幼苗生长和生理特性对不同遮阴强度响应有差异,主要表现在随着遮阴强度的增加,株高生长加快,地径粗生长减缓,生物量分配倾向于地上部分,幼苗由“矮粗”逐渐转变为“细高”。但是过度遮阴不利于杉木幼苗的生长,导致幼苗生物量积累减少,C、N、P积累量降低。

关键词: 杉木幼苗, 遮阴, 化学计量特征, 养分利用策略

Abstract:

【Objectives】To explore the adaptive strategy of seedlings under different shade intensities, the growth, biomass accumulation and allocation as well carbon (C), nitrogen (N) and phosphorus (P) accumulation, allocation and stoichiometric characteristics were measured in different organs of Chinese fir seedlings. The results help to elucidate changes in C, N, P elements under different shading treatments, and provide a theoretical basis for cultivation at the seedling stage, stand light environment regulation and management. 【Method】After one year of growth, Chinese fir seedlings were selected as the research object in this study, and five different light intensities were set up with artificial shading 0% (as control, no shade), 40%, 60%, 85% and 95% shading. The experiment was undertaken over one year. The height increment, diameter increment, biomass accumulation and allocation, root to shoot ratios, C, N, P accumulations, and their stoichiometric characteristics were measured at the end of the experiment in different organs of Chinese fir seedlings under various shade intensities.【Result】(1) The height of seedlings increased as the shade increased, while the diameter significantly decreased. Biomass of the root, stem, leaf, total, and root to shoot ratios decreased as the shade increased, while the stem and leaf biomass ratios increased. (2) The accumulations of C, N, P of root, stem, leaf and the total accumulations decreased with the increased of shade intensities. The C and N distribution ratios increased in the aboveground part (stem and leaf) of the seedlings, and decreased in the underground part of the seedling (root). (3) C/N (the mass ratio, same as below) and C/P of seedlings showed the same change trend, which initially increased and then decreased with increasing shading intensities. The N/P in each organ was lower than 14, indicating that Chinese fir seedling growth under different shading intensities was restricted by nitrogen. 【Conclusion】Chinese fir seedlings could regulate nutrient accumulation and distribution under different shading treatments, affecting biomass accumulation. Chinese fir seedlings showed different growth and physiological strategies under different shading intensities, such as greater growth in height, slower growth in diameter, with biomass allocation being invested in the aboveground parts under high shading intensities. Seedlings gradually changed from “short and thick” to “thin and tall”. However, the excessive shading may inhibit seedling growth, and result in less biomass accumulations, and low C, N, P accumulations.

Key words: Chinese fir (Cunninghamia lanceolata) seedling, shade intensities, stoichiometric characteristics, nutrient utilization strategy

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