College of Forestry, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China.
Department of Biosystems Engineering, College of Engineering, Auburn University, Auburn, AL, 36849, USA.
Environ Monit Assess. 2021 Jul 28;193(8):530. doi: 10.1007/s10661-021-09338-x.
Leaves of trees experience the maximum brunt of exposure and undergo certain changes in physiological traits responding to air pollution, and then, the specific leaf traits can be the indicators of air pollution in an area. However, due to the diversity of sources, the composition of air pollutants is very complex. This makes it difficult to predict air pollution using physiological differentiation of leaves. The purpose of this investigation was to examine potential of Ligustrum lucidum Ait. leaf measurement as a method to predict the air pollutants in Luoyang, China. Leaves of roadside L. lucidum were studied from the city center with serious air pollution to relatively unpolluted areas. Leaf size, stomatal traits, and non-structural carbohydrate were measured. The particulate and gaseous pollutants (including sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) were investigated too. The results showed that the leaf area and soluble sugar content decreased, while the aspect ratio of leaves increased in heavily polluted areas. As pollution increased, the stomatal traits in different crown positions were changed differently. No significant correlation was found between ozone content and the measured traits of leaves. The responses found in the physiological differentiation of the leaves reflect acclimation to air pollution. The soluble sugar content of the leaves could be used to indicate the short-term stress of air pollution, the area, and aspect ratio of leaves are indicative of the long-term stress due to air pollution. Therefore, physiological traits of L. lucidum leaves appeared to be significant predictive factors for the air pollutants in urban areas.
树木的叶子承受着最大的暴露冲击，并在生理特征上发生某些变化，以应对空气污染，然后，特定的叶子特征可以成为该地区空气污染的指标。然而，由于来源的多样性，空气污染物的组成非常复杂。这使得使用叶子的生理差异来预测空气污染变得困难。本研究的目的是检验女贞叶测量作为预测中国洛阳空气污染物的方法的潜力。研究了来自市中心严重空气污染区到相对未污染区的路边女贞叶。测量了叶子的大小、气孔特征和非结构性碳水化合物。还调查了颗粒状和气体污染物（包括二氧化硫、二氧化氮、一氧化碳和臭氧）。结果表明，在污染严重的地区，叶子的面积和可溶性糖含量减少，而叶子的长宽比增加。随着污染的增加，不同树冠位置的气孔特征发生了不同的变化。臭氧含量与所测叶片特征之间没有发现显著相关性。叶片生理分化中的反应反映了对空气污染的适应。叶片的可溶性糖含量可用于指示空气污染的短期胁迫，而叶片的面积和长宽比则表明由于空气污染而产生的长期胁迫。因此，女贞叶的生理特征似乎是城市地区空气污染物的重要预测因素。
