植物生态学报 ›› 2017, Vol. 41 ›› Issue (5): 559-569.doi: 10.17521/cjpe.2016.0248

• 研究论文 • 上一篇    下一篇

光照强度变化对5种耐阴植物氮磷养分含量、分配以及限制状况的影响

颉洪涛, 虞木奎, 成向荣*()   

  1. 华东沿海防护林生态系统国家定位观测研究站, 中国林业科学研究院亚热带林业研究所, 杭州 311400
  • 出版日期:2017-05-10 发布日期:2017-06-22
  • 通讯作者: 成向荣 E-mail:chxr@caf.ac.cn
  • 作者简介:

    * 通信作者Author for correspondence (E-mail:sunzhiqiang1956@sina.com)

  • 基金资助:
    基金项目 浙江省与中国林业科学研究院省院合作林业科技项目(14204005和16204002)、国家自然科学基金(31300519)和中央级公益性科研院所基本科研业务费专项资金(RISF6930)

Effects of light intensity variation on nitrogen and phosphorus contents, allocation and limitation in five shade-enduring plants

Hong-Tao XIE, Mu-Kui YU, Xiang-Rong CHENG*()   

  1. National Field Research Station of Eastern China Coastal Forest Ecosystem, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
  • Online:2017-05-10 Published:2017-06-22
  • Contact: Xiang-Rong CHENG E-mail:chxr@caf.ac.cn
  • About author:

    KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

摘要:

增强对耐阴植物在不同光环境下氮磷生理响应的理解可以为改善人工林林分结构和提高生态系统功能提供借鉴。该文选取5种亚热带地区具有较高生态和经济价值的耐阴植物幼苗为研究对象, 通过控制实验模拟不同光环境, 设置5个梯度探究光照强度变化对耐阴植物氮磷养分含量、分配以及限制状况的影响。结果显示: 随着光强减弱, 5种耐阴植物的总生物量和总氮磷积累均呈降低趋势, 但各器官氮磷含量有增加趋势。其中, 栀子(Gardenia jasminoides)氮含量最高, 红茴香(Illicium henryi)氮含量最低; 乌冈栎(Quercus phillyraeoides)和栀子的磷含量明显高于山杜英(Elaeocarpus sylvestris)、朱砂根(Ardisia crenata)和红茴香。栀子和乌冈栎在极低光强(6%自然光强)下氮和磷含量均为最高, 朱砂根和红茴香则分别在低光强(15%自然光强)和中等光强(33%自然光强和52%自然光强)时氮磷含量最高; 而杜英氮磷含量最高时对应的光照强度不同, 分别为52%自然光强和6%自然光强。杜英、朱砂根和红茴香各器官的氮磷含量均为叶片>根系>枝干, 栀子和乌冈栎为根系>叶片>枝干。随光强减弱, 氮磷利用格局发生变化。在较高光强(100%自然光强)下, 5种植物各器官氮含量变化表现出良好的一致性, 但在较低光强(15%自然光强和6%自然光强)下表现出明显的分异; 光强减弱时, 植物各器官磷含量变化在红茴香、栀子和乌冈栎上表现出一致性, 但在杜英和朱砂根上表现为分异性。光强减弱显著影响耐阴植物器官氮磷比, 但未根本改变植物生长的元素受限状况。光强变化和树种差异均对耐阴植物在异质性光环境中的氮磷利用和分配产生调节, 进而影响总生物量和总氮磷积累, 这源于植物氮磷利用策略的改变。因此, 在构建复层异龄林时应考虑耐阴植物氮磷养分平衡对光强的偏好。

关键词: 光强, 耐阴植物, 氮含量, 磷含量, 分配, 适应策略

Abstract:
Aims To enhance the understanding on nitrogen (N) and phosphorus (P) physiological responses to different light environments in shade-enduring plants and provide references to improve the stand structure and ecosystem functions of plantation forests.Methods We selected seedlings of five shade-enduring species with high ecological and economic value in subtropical area of China to study the effects of light intensity on leaf N and P contents, allocation and nutrient limitation in shade-enduring plants. A light intensity gradient of five different levels was set to simulate the varying understory light environment.Important findings With decreasing light intensity, the total biomass and total N and P accumulation of five shade-enduring plants all showed a decreasing trend, but N, P contents in different organs increased. Among them, Gardenia jasminoides (GJ) had the highest while Illicium henryi (IH) had the lowest N content; The P contents of Quercus phillyraeoides (QP) and GJ were significantly higher than Elaeocarpus sylvestris (ES), Ardisia crenata (AC) and IH. QP and GJ had the highest N, P contents under extremely low light intensity (6% natural light intensity) condition (LIC), while AC and IH had the highest N and P contents in low (15% natural light intensity) and moderate (33% and 52% natural light intensity) LIC. ES demanded differently for LIC on N and P, which were 52% and 6% natural light intensity, respectively. N and P allocation of ES, AC and IH followed leaf > root > stem, but for QP and GJ were root > leaf > stem. Decreasing LIC significantly affected N and P allocation. N content variations shown good consistency among different organs under higher LIC (100% natural light intensity) while distinct variability under lower LIC (15% and 6% natural light intensity) in all five species. Phosphorus contents exhibited good consistency in IH, QP and GJ but varied in ES and AC. Decreasing LIC significantly affected organ N/P ratios of shade-enduring plants, but the fundamental growth restriction patterns remained. Light intensity variation and tree species co-regulated N, P utilization and allocation in shade-enduring plants, and then affected the total biomass and total N, P accumulation, which might result from the change of N and P utilization strategy. Therefore, light intensity preference and N, P nutrient balances in shade-enduring plants should be taken into account when constructing multiple layer and uneven-aged forests.

Key words: light intensity, shade-enduring plant, N content, P content, allocation, adaptation strategy