城市森林群落林冠结构与林下光环境的关系  

Relationship between canopy structures and understory light availability in urban forest communities

作　　者：黄练忠 杨进良 徐庆华 张星元 阚蕾 张璐 HUANG Lianzhong;YANG Jinliang;XU Qinghua;ZHANG Xingyuan;KAN Lei;ZHANG Lu(Dongguan Dalingshan Forest Park,Dongguan 523725,Guangdong,China;College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510624,Guangdong,China)

机构地区：[1]广东省东莞市大岭山森林公园,广东东莞523725 [2]华南农业大学林学与风景园林学院,广东广州510642

出　　处：《中南林业科技大学学报》2019年第9期53-58,共6页Journal of Central South University of Forestry & Technology

基　　金：广东省省级林业发展及保护专项资金(林业科技创新项目)(2017KJCX037);广东省自然科学基金项目(2015A030313403);广东省林业科技计划项目(2130211-30299-1)

摘　　要：城市森林群落是城市生态系统的重要组成部分,研究城乡梯度下城市森林群落林冠结构与林下光环境的关系对提高广州城市森林质量、创建珠三角国家森林城市群具有重要意义。采用经典群落学调查方法和半球面影像技术,定量研究了城市森林群落林冠结构对林下光环境的影响,并筛选出对林下光环境影响较强的林冠结构因子。结果表明:1)市区、近郊和远郊森林群落的林冠结构参数没有遵循同一变化模式。3个城市森林群落林冠层的胸径在不同区域间差异不显著(P>0.05),但树高、林冠开度与叶面积指数在不同区域间均呈极显著差异(P<0.001)。2)沿城乡梯度,3个城市森林群落林下直射光、林下散射光和林下总光照的差异性均达到极显著水平(P<0.001),林下散射光与林冠结构的关系更密切。近郊和远郊的冠层林下光环境特征相似,均与市区差异显著。3)沿城乡梯度,城市森林群落林冠结构对林下光环境的影响不一致。胸径和树高对林下光环境无影响,林冠开度的影响较小,但叶面积指数的影响较大。Urban forest community is an important component of urban ecosystem. It is of great significance to study the relationship between canopy structures and understory light availability of urban forest community with urban-rural gradient to improve the quality of urban forest in Guangzhou and establish the national forest city cluster in pearl river delta. Using the classical community survey methods and hemispherical imaging techniques, the influence of canopy structures on understory light availability of urban forest community, and the main factors werestudied. The results showed that: 1) The canopy structures parameters did not show the same pattern of the forest community in urban area, suburb and exurb. The DBH of forest community showed no significant difference among the three urban forests(P>0.05), however, tree height, canopy openness and leaf area index all showed an extremely significant difference among the forest community in urban area, suburb and exurb(P<0.001). 2) The transmitted direct light, transmitted diffuse light and transmitted total light in the three urban forests significantly differed along the urban-rural gradient(P<0.001), while the transmitted diffuse light had stronger correlation with canopy structure. The understory lightavailability of forest community in suburb and exurb were similar, both of which significantly differed from the urban forests. 3) The effects of canopy structure of urban forests to understory light availability were inconsistent along the urban-rural gradient. The DBH and tree height did not affect the understory light availability. In the urban forests, the understory light availability weakly affected by the canopy openness, while strongly by the leaf area index.

关 键 词：林分因子 林冠开度 叶面积指数 林下直射光 林下散射光 林下总光照 

分 类 号：S718.5[农业科学—林学]