• 研究论文 •

### 林冠环境对润楠幼苗构型和生物量分配的影响

1. 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
• 收稿日期:2020-11-06 接受日期:2021-03-04 发布日期:2021-12-15
• 通讯作者: * E-mail: ycyang@cqu.edu.cn
• 作者简介:廖睿燕, 女, 1995年生, 硕士研究生。主要从事植被生态学和生物多样性研究。E-mail: liaorymv@163.com
• 基金资助:
重庆市技术创新与应用示范专项重点研发项目(cstc2018jszx-zdyfxmX0007)资助

### Effect of canopy condition on Machilus nanmu seedling configuration and biomass allocation

LIAO Rui-yan, WU Xiao-qi, JIN Cheng, HUANG Li, QIAN Shen-hua, YANG Yong-chuan*

1. Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
• Received:2020-11-06 Accepted:2021-03-04 Published:2021-12-15
• Contact: * E-mail: ycyang@cqu.edu.cn
• Supported by:
Major Theme of Chongqing Technology Innovation and Application Demonstration Special Project (cstc2018jszx-zdyfxmX0007).

Abstract: The adaptation strategy of seedlings plays a decisive role in population regeneration. Machilus nanmu is a tree species belonging to Lauraceae, which is national class Ⅱ protected species and one of the dominant species in the evergreen broadleaved forest in Jinyun Mountain, Chongqing. Therefore, it is of great significance to understand the adaptation strategies of M. nanmu seedlings to maintain population regeneration and protect the biodiversity of evergreen broadleaved forest. We studied the temporal dynamics of early adaptation strategy of M. nanmu in Jinyun Mountain in Chongqing and its response to heterogeneous habitats from the perspective of morphology and biomass allocation. The seedlings of M. nanmu were classified into different age stages (stage 1: 1-3 a; stage 2: 4-6 a; stage 3: 7-9 a) under different canopy environments (gap/understory). Stem configurations (except branch angle) and leaf inclination angle of M. nanmu seedlings in the gap were significantly greater than understory at stages 2 and 3. Root configurations (except root diameter) and leaf area were significantly greater than that in the understory at stages 1 and 2. Specific leaf area in the gap was significantly smaller than understory at all three stages. Across all the conditions, biomass distribution was dominated by leaves. From the stage 2, stem biomass distribution of M. nanmu seedlings in the gap was increased, while root biomass distribution was decreased. There was no significant variation in root biomass of M. nanmu seedlings in the understory. The coordination among different organs of M. nanmu seedlings would help their adaptation to different habitats. Root and leaf of M. nanmu seedlings in the gap were significantly correlated, with the correlation changing from positive to negative as the age increased. While in the understory, there was significant positive correlation between root and stem, but no correlation between root and leaf. The slope of SMA equation of branch weight and branch length had significant difference under different canopy environments only at stage 3, while the slope of SMA equation of leaf and root biomass and configuration had no significant difference. Most of the SMA equation intercepts between biomass and configuration differed significantly at stage 2.