Abstract
The present study evaluated the air pollution tolerance index (APTI), anticipated performance index (API), enrichment factor (EF), pollution load index (PLI), bioaccumulation coefficient (BAC), and metal accumulation index (MAI) in grown plants of industrial ecosystems of Najafabad County near the Isfahan megacity (Iran). The existence of major, minor and trace mineral elements, physiological (pH of leaf extract and relative water content) and biochemical (proline, reducing sugar, ascorbic acid, and total chlorophyll content) factors in Clerics siliquastrum, Melia azedarach, Caesalpinia gilliesii, Eucalyptus camaldulensis, Robinia pseudoacacia, and Morus alba were evaluated to assess their suitability for phytoremediation and/or phytomonitoring. The results showed that M. azedarach and E. camaldulensis had higher APTI and API values and were categorized in the tolerant plant group. The most important factors influencing the APTI of R. pseudoacacia, E. camaldulensis, C. gilliesii, M. azedarach, C. siliquastrum and M. alba were ascorbic acid (88.1%), the pH of leaf extract (45.7%), ascorbic acid (78.9%), the pH of leaf extract (98.8%), the total chlorophyll content (56.1%), and the relative water content (54.6%), respectively. Proline showed a strong and negative correlation with the APTI (r = −0.72). Reducing sugar showed a moderate and negative correlation with the total chlorophyll (r = −0.63). The PLI showed a high pollution load for all species, especially M. azedarach. The highest values of EF, BAC, and MAI were obtained in C. siliquastrum (117.46), R. pseudoacacia (417.79), and M. azedarach (8.92), respectively. Based on the overall results of this study, it is recommended that M. azedarach be used as a tolerant species for green space development and C. siliquastrum and R. pseudoacacia as both passive bio-monitors and bio-mitigators in industrial ecosystems.
Introduction
This section explains the environmental challenges posed by urbanization and industrialization, particularly in developing countries like Iran. It highlights the need for phytomonitoring and phytoremediation using plants to assess and mitigate pollution. The importance of indices such as APTI (Air Pollution Tolerance Index), API (Anticipated Performance Index), and metal accumulation metrics is introduced to evaluate plant effectiveness in polluted ecosystems.
Materials and Methods
This part details the study location (Najafabad, Isfahan), sampling procedures, and the plant species selected for analysis. It outlines the collection and preparation of leaf and soil samples, and describes how physiological, biochemical, and chemometric analyses were performed. Various pollution and phytoremediation indices (APTI, API, MAI, BAC, EF, PLI) are also explained, along with techniques like ICP-MS and SEM-EDX used for elemental and micromorphological assessment.
Results and Discussion
Findings show differences in pollutant accumulation and tolerance among the studied plants. Melia azedarach had the highest APTI and MAI, making it most tolerant and suitable for green space development. Robinia pseudoacacia showed the highest bioaccumulation coefficient (BAC), while Cercis siliquastrum demonstrated strong phytomonitoring potential. The SEM-EDX analysis confirmed differences in surface micromorphology that affect pollutant trapping efficiency. Relationships among biochemical traits, pollution indices, and plant performance are also analyzed.
Conclusions
The study concludes that certain species like M. azedarach, R. pseudoacacia, and C. siliquastrum are effective for use in green infrastructure in industrial regions due to their pollutant tolerance and phytoremediation capacity. It recommends these species for future urban ecological planning and environmental management in polluted areas.