河北省张家口市常见绿化树种叶片特征及滞纳大气颗粒物能力

Leaf Characteristics and Ability to Retention Atmospheric Particulate Matter of Common Greening Tree Species in Zhangjiakou City,Hebei Province

为分析河北省张家口市常见绿化树种叶片特征及滞纳大气颗粒物能力的差异,以张家口市人民公园6种常见绿化树种为对象,通过观测叶片特征,测定不同月份叶片PM_(2.5)和PM_(10)滞纳量,分析不同树种及月份叶片滞纳大气颗粒物能力差异的原因。结果表明:张家口地区6种常见绿化树种4—10月份叶面积平均每月PM_(2.5)滞纳量为(0.35±0.21)~(0.80±0.35)μg·cm^(-2),PM_(10)滞纳量为(1.31±0.68)~(2.64±1.32)μg·cm^(-2),油松(Pinus tabuliformis)滞纳量最大,银杏(Ginkgo biloba)最小,且两者差异显著(P<0.05)。针叶树种PM_(2.5)及PM_(10)滞纳量均大于阔叶树种。10月份PM_(2.5)和PM_(10)滞纳量均最大,分别为(1.07±0.37)、(3.33±1.13)μg·cm^(-2);8月份均最小,分别为(0.31±0.09)、(0.59±0.54)μg·cm^(-2)。通过扫描电镜观察叶片,发现叶表面沟壑越深、气孔越多,叶片滞纳大气颗粒物的能力越强。通过原子力显微镜观察可以发现,叶片滞纳大气颗粒物的能力与叶片粗糙度呈正相关。选择滞纳大气颗粒物为目标绿化树种时,应优先选择油松等针叶树种。

To analyze the differences in leaf characteristics and retention capacity of atmospheric particulate matter among common greening tree species in Zhangjiakou City,Hebei Province,six common greening tree species in Zhangjiakou City People’s Park were selected as the research objects.By observing leaf characteristics,measuring the retention amount of PM_(2.5) and PM_(10) on leaves in different months,the reasons for the differences in the retention capacity of atmospheric particulate matter on leaves of different tree species and months were analyzed.The results showed that from April to October,the average monthly PM_(2.5) retention amount per unit leaf area of the six common greening tree species in Zhangjiakou City was(0.35±0.21)-(0.80±0.35)μg·cm^(-2),and the PM_(10) retention amount was(1.31±0.68)-(2.64±1.32)μg·cm^(-2).Pinus tabuliformis had the highest retention amount,while Ginkgo biloba had the lowest,and the difference between the two was significant(P<0.05).The retention of PM_(2.5) and PM_(10) in coniferous tree species was higher than that in broad-leaved tree species.The retention of PM_(2.5) and PM_(10) in October was the highest,which were(1.07±0.37)and(3.33±1.13)μg·cm^(-2),respectively.The lowest values were(0.31±0.09)and(0.59±0.54)μg·cm^(-2)in August,respectively.The leaves were observed by scanning electron microscopy,and it was found that the deeper the gully on the leaf surface and the more the pores,the stronger the retention capacity of atmospheric particulate matter on the leaves.Through atomic force microscopy observation,it was found that the retention capacity of atmospheric particulate matter on leaves was positively correlated with leaf roughness.When choosing retention atmospheric particulate matter as the target greening tree species,coniferous tree species such as P.tabulaeformis should be preferred.