Abstract:

In order to deeply explore the physiological and ecological response of shrub species to atmospheric particulate matter (PM) pollution, this study selected eight kinds of common shrubs in three dust source zones (i.e., coal combustion zone, oil combustion zone, and clean zone) in Qingdao as the objects. and quantified particles of different sizes (TSP, PM_>10, PM₁₀ and PM_2.5) per unit leaf area using the 3-layer membrane filtration method. The physiological indexes of shrub leaves after dusting were compared and measured, and the effects of particle properties intercepted by leaves on plant physiology were analyzed. The results showed that: (1) The dust retention of shrubs in the study area was the strongest in the coal combustion zone, followed by the oil combustion zone, and the clean zone. PM_>10 was the main particle retained by leaves. Among all shrubs, Buxus sinica had the highest absorption capacity for TSP, PM_>10, and PM₁₀, and the average dust retention per unit leaf area was 4.89 g∙m^-2, 3.45 g∙m^-2 and 1.54 g∙m^-2, respectively. Euonymus japonicus had the highest interception capacity for PM_2.5, and the average value was 0.21 g∙m^-2. Pyracantha fortuneana showed the lowest absorption level for particles with different sizes. (2) With the aggravation of dust pollution, the chlorophyll of shrubs decreased, while the contents of carotenoid, ascorbic acid, and leaf dry matter increased. (3) Correlation analysis showed that Cercis chinensis was a suitable indicator plant for air pollution, because there was a significant correlation between its leaf dust retention and various physiological indexes (P<0.05). However, Rosa multifolora leaves might not be vulnerable to dust stress, as no significant correlation was found between their dust retention and physiological indexes. (4) Redundancy analysis (RDA) showed that under air pollution, plant chlorophyll was highly susceptible to the size of PM, and carotenoid was susceptible to dust sources. This study can provide a scientific basis for the selection of tree species, site configuration, and further quantitative evaluation of dust retention benefits of tree species in different dust source zones in Qingdao's urban greening construction.

Key words: atmospheric particulate matter, shrub, dust retention capacity, physiological indexes, physiological response, particle size class

摘要：

为深入探究灌木树种对大气颗粒物（PM）污染的生理响应,以青岛市3种尘源区域（燃煤区、燃油区和清洁区）中常见的8种灌木为对象,采用3级滤膜过滤法测定了灌木单位叶面积滞留不同粒径颗粒物（TSP、PM_>10、PM₁₀和PM_2.5）的质量,并对蒙尘后灌木叶片的生理指标进行了比较测定,分析了叶片截留颗粒物的性质对植物生理指标的影响。结果表明,（1）研究区域内灌木滞尘量总体表现为燃煤区>燃油区>清洁区,且叶片所截留的颗粒物以PM_>10为主,其中小叶黄杨（Buxus sinica）对TSP、PM_>10和PM₁₀的吸滞能力最强,平均单位叶面积滞尘量分别为4.89、3.45、1.54 g∙m^-2;大叶黄杨（Euonymus japonicus）对于PM_2.5的截留量最高,平均为0.21 g∙m^-2;而火棘（Pyracantha fortuneana）对不同粒径颗粒物均呈现出最低的吸滞水平。（2）随粉尘污染的加重,灌木叶绿素呈下降趋势,类胡萝卜素、抗坏血酸和叶干物质含量呈上升趋势。（3）相关性分析表明,紫荆（Cercis chinensis）叶片滞尘量与各生理指标之间具有显著相关关系（P<0.05）,适合作为大气污染的指示植物;蔷薇（Rosa multifolora）叶片滞尘量与各生理指标之间无显著性相关,表明其不易受到蒙尘胁迫的影响。（4）冗余分析（RDA）表明,在大气污染下,植物叶绿素极易受到颗粒物粒径的影响,而类胡萝卜素易受到粉尘来源的影响。该研究结论可为青岛市绿化建设中不同尘源区域树种的选择、立地配置与滞尘效益的进一步量化评价提供科学依据。

关键词: 大气颗粒物, 灌木, 滞尘能力, 生理指标, 生理响应, 颗粒物径级