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。
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 sub- tropical area of China to study the effects of light intensity on learN and P contents, allocation and nutrient limita- tion in shade-enduring plants. A light intensity gradient of five different levels was set to simulate the varying un- derstory 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, Gardeniajasminoides （G J） 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 ofES, 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 con- tent 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 shad
作者
颉洪涛
虞木奎
成向荣
XIE Hong-Tao YU Mu-Kui CHENG Xiang-Rong(National Field Research Station of Eastern China Coastal Forest Ecosystem, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2017年第5期559-569,共11页
Chinese Journal of Plant Ecology
基金
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)
中央级公益性科研院所基本科研业务费专项资金(RISF6930)
关键词
光强
耐阴植物
氮含量
磷含量
分配
适应策略
light intensity
shade-enduring plant
N content
P content
allocation
adaptation strategy
