Assessment of the Relationships Between Leaf Characteristics with Air Pollutants: A Case Study on Oriental Plane (Platanus orientalisL.) and Caucasian Hackberry (Celtis caucasicaWilld.)

Abstract

Abstract Background Plants are sensitive to air pollution by altering their vital processes such as growth or photosynthesis. Leaf characteristics reflect the adaptive mechanism of plants to their environment. This mechanism is demonstrated through changes in anatomical, morphological, and physiological characteristics relative to environmental changes. Methods Samples were taken from 2 species of Platanus orientalis L. and Celtis caucasica Willd. in 10 urban forests of Tehran, Iran. In each study area, 50 leaves were collected from different directions of the canopy of each tree, and their area was measured by a leaf area meter instrument in a laboratory. Leaf moisture and specific leaf area (SLA) were also calculated. The data of air pollutants were obtained from the nearest pollution measurement stations to each study location. Results The average percentage of moisture for P. orientalis and C. caucasica was calculated as 49.6% and 41.9%, respectively. The averages of SLA were estimated 9.2 and 6.5 cm 2 /g, respectively. The average leaf area was 36 and 6.04 cm 2 , respectively. The correlation between quantitative variables of leaf (leaf area and SLA) and air pollutant appeared in both study species, only there was a significant negative relationship between leaf area and O 3 . This relationship was stronger in C. caucasica ( R 2 = −0.78). Conclusion The results of this research showed that both species showed similar behavior against air pollutants, but C. caucasica showed more reaction.