| 摘要: |
| 为探究城市森林冠层结构的时空变化规律以及对林下光照分布的影响, 以广东树木公园和华
南农业大学树木园的典型植物群落为研究对象, 依据研究区植物分布和地形特征设置 6 条调查样带, 于
2022 年 11 月—2023 年 10 月利用半球面影像技术连续监测群落的林冠开度 (CO)、 叶面积指数 (LAI)、
林下直射光 (TDir)、 散射光 (TDif) 和总光照 (TTot), 并通过典型相关分析探讨冠层结构和林下光环
境之间的关系。 结果表明, 各群落间 CO 和 LAI 均存在极显著差异 (P<0. 01), CO 的范围为 11. 98% ~
31. 28%, LAI 为 1. 50~3. 03, 阔叶林群落 (Broad-leaved community) 和南洋楹群落 (Falcataria falcata
community) CO 随季节更替呈现先降低后增加的显著变化趋势 (P<0. 05), LAI 变化方向相反, 其余群
落变化不明显。 各群落间 TDir、 TDif 和 TTot 均存在极显著差异 (P< 0. 01), 范围分别为 2. 62 ~ 7. 45、
2. 64~6. 72、 5. 14 ~ 14. 18 mol·m
-2 ·d
-1
, 除大叶相思群落 (Acacia auriculiformis community) TDir 和
TTot 的月际变化不显著外, 其余群落的林下光环境参数随季节更替呈现先增加后降低的显著变化趋势
(P<0. 05)。 林下光环境与 CO 呈极显著正相关 (P<0. 01), 与 LAI 呈极显著负相关, TDif 对林下光环境
的解释量最大。 综上认为, 不同群落的冠层结构和林下光环境存在显著的时空异质性, 冠层结构对林下
光环境有明显的控制作用, 气温、 光照、 水分等环境因子的季节性变化和自然干扰是森林冠层季节变化
的重要影响因素。 |
| 关键词: 冠层结构 林下光环境 季节动态 半球面影像技术 树木园 |
| DOI：10. 20221 / j. cnki. 2096-2053. 202504007 |
| 分类号: |
| 基金项目:广东省级财政资金项目 (2025KJXM02), 林草科技创新平台运行补助项目 ( 2024132066), 林草科技创新平台运行补助 项目 (2023132061)。 |
|
| Seasonal Dynamics of Canopy Structure and Understory Light Environment in Plant Communities of Urban Arboretums |
|
WU Guozhang1,2,3,2, GAN Xianhua1, CAI Jian1, ZHANG Weiqiang1, HUANG Fangfang1, HUANG Yuhui1, WANG Ning1, SU Yuqiao1
|
|
1.Guangdong Key Laboratory of Silviculture,Protection and Utilization/Guangdong Academy of Forestry,Guangzhou;2.China;3.College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou
|
| Abstract: |
| To explore the spatiotemporal variation patterns of canopy structure and its impact on understory
light distribution, typical plant communities in Guangdong Tree Park and South China Agricultural University
Arboretum were selected as research objects. Based on plant distribution and topographic characteristics in the
study area, six survey transects were established. From November 2022 to October 2023, hemispherical photography was used to continuously monitor canopy openness (CO), leaf area index (LAI), transmitted direct
solar radiation ( TDir ), transmitted diffuse solar radiation ( TDif ), and transmitted total solar radiation
(TTot) of the communities. The relationship between canopy structure and understory light environment was investigated using canonical correlation analysis. The results showed that there were extremely significant differences in CO and LAI among the communities (P<0. 01), with CO ranging from 11. 98% to 31. 28% and LAI
ranging from 1. 50 to 3. 03. The broad-leaved community and the Falcataria falcata community showed a significant trend of first decreasing and then increasing in CO with seasonal progression (P< 0. 05), while LAI
showed the opposite patterns. Changes in other communities were not significant. There were extremely significant differences in TDir, TDif and TTot among the communities (P<0. 01), with ranges of 2. 62-7. 45, 2. 64-
6. 72, and 5. 14-14. 18 mol·m
-2·d
-1
, respectively. Except for the Acacia auriculiformis community, which
showed no significant monthly variations in TDir and TTot, the understory light parameters of other communities
exhibited a significant trend of first increasing and then decreasing with seasonal progression (P<0. 05). The
understory light environment was extremely significantly positively correlated with CO (P<0. 01) and significantly negatively correlated with LAI, while TDif contributed the highest explanation for the understory light
environment. In conclusion, the canopy structure and understory light environment of different communities
exhibited significant spatiotemporal heterogeneity. The canopy structure played a notable controlling role in the
understory light environment, and seasonal changes in environmental factors such as temperature, light, and
moisture, along with natural disturbance, were important factors influencing seasonal variations in the forest
canopy. |
| Key words: canopy structure understory light environment seasonal dynamics hemispherical photography arboretum |
