城市热岛强度对不同叶片质地绿化树种叶片水分相关性状的影响  

Effects of urban heat island intensity on leaf water-relevant traits of greening tree species with different leaf textures

作　　者：徐景亮 朱济友 闫香如 徐程扬[1] Xu Jingliang;Zhu Jiyou;Yan Xiangru;Xu Chengyang(School of Forestry,Beijing Forestry University,Beijing 100083,China;School of Environmental Science and Engineering,Nankai University,Tianjin 300350,China)

机构地区：[1]北京林业大学林学院,北京100083 [2]南开大学环境科学与工程学院,天津300350

出　　处：《北京林业大学学报》2024年第9期97-106,共10页Journal of Beijing Forestry University

基　　金：北京市自然科学基金项目(8222067);中央高校基本科研业务费专项(63231130)。

摘　　要：【目的】了解两种不同质地叶片水分相关性状对城市热岛的响应,揭示不同质地叶片对城市热岛的适应方式是否有所区别。【方法】在北京市4个典型热岛强度地块中,以常见纸质叶和革质叶绿化树种为对象,研究与树木水分过程相关的叶脉、气孔性状以及叶表皮厚度的变化。【结果】(1)纸质叶的叶脉密度、气孔密度、气孔长度、最大气孔导度、上表皮厚度在强热岛区相对于强冷岛区表现出增大的趋势,叶脉直径在强热岛区相对于强冷岛区表现出减小的趋势;(2)革质叶的叶脉密度、叶脉直径、气孔长度在强热岛区相对于强冷岛区表现出增大的趋势,气孔密度、最大气孔导度、上表皮厚度在强热岛区相对于强冷岛区表现出减小的趋势;(3)不同质地叶片表现出了不同的水分相关性状相关性,但两者均表现出气孔密度与最大气孔导度呈正相关(p<0.05),两种质地叶片通过调整水分相关性状之间不同的关系来适应城市热岛的胁迫。【结论】城市热岛会显著影响树木叶片的水分相关性状,不同质地的叶片应对城市热岛环境所采取的适应策略有所区别。纸质叶采取了加大水分供应,提高蒸腾作用,帮助植物体降温的策略;革质叶采取了提高水分的运输,减小蒸腾水分耗散的策略。两种叶片质地树种的叶脉与气孔均存在协同进化的现象。对于处于较高热岛强度的城市公园,应参考水分相关性状等指标选择耐高温树种,并且在高温季节采取加大灌溉量和人工降温等措施。[Objective]This paper aims to explore the response of water content correlation between two different leaf textures to urban heat islands,and to reveal whether there are differences in the adaptation methods of varied leaf textures to urban heat islands.[Method]In four typical heat island intensity plots in Beijing,common chartaceous and coriaceous leaf greening tree species were used as objects to study the changes in leaf vein,stomatal traits,and leaf epidermal thickness related to tree water processes.[Result](1)The leaf vein density,stomatal density,stomatal length,maximum stomatal conductivity,and upper epidermal thickness of chartaceous leaves showed an increasing trend in the strong heat island area compared with the strong cold island area,while the leaf vein diameter showed a decreasing trend in the strong heat island area compared with strong cold island area.(2)The vein density,vein diameter,and stomatal length of coriaceous leaves showed an increasing trend in the strong heat island area compared with strong cold island area,while the stomatal density,maximum stomatal conductivity,and upper epidermal thickness showed a decreasing trend in the strong heat island area compared with strong cold island area.(3)Different leaf textures showed varied water related correlations,but both showed a positive correlation between stomatal density and maximum stomatal conductance(p<0.05).The two types of leaf textures adapted to urban heat island stress by adjusting the different relationships between water related traits.[Conclusion]Urban heat islands significantly affect the water related traits of tree leaves,and different textures of leaves adopt different adaptation strategies to the urban heat island environment.Chartaceous leaves adopt a strategy of increasing water supply,improving transpiration,and helping plants cool down.The coriaceous leaves adopt a strategy of increasing water transportation and reducing transpiration water dissipation.There is a phenomenon of co-evolution between the leaf veins and sto

关 键 词：热岛效应 叶片质地 叶片水分相关性状 权衡策略 城市林业 

分 类 号：S732[农业科学—林学]