Air Pollution Tolerance Index Research Articles

Assessing the relationship between the biochemical and the morphological factors (leaf surface area and leaf surface texture) of industrial and roadside plants.

The study of biochemical parameters provides an idea of the resistance of plants against air pollutants. Biochemical and Physiological parameters are studied with the help of Air pollution tolerance index (APTI). Fifteen plant species were evaluated to assess biochemical and APTI from two polluted sites (Phagwara Industrial area and Phagwara Bus stand area). The values of APTI were found to be highest for Mangifera indica (19.6), Ficus religiosa (19.3), and Ficus benghalensis (15.8) in the industrial area. On the roadside, Mangifera indica (16.8), Ficus benghalensis (16.5), and Ficus religiosa (16.4). Mangifera indica, Ficus religiosa, and Ficus benghalensis were found to be excellent performers in reducing pollution at both the sampling sites as per the APTI values. The order of tolerance was Mangifera indica > Ficus religiosa > Ficus benghalensis > Polyalthia longifolia > Mentha piperita in both the polluted sites. Morphological changes were observed in the plants, suggesting the possibility of pollution stress, which is probably responsible for the changes in biochemical parameters. As a result, the relationship between morphological and biochemical parameters of selected plant species growing in roadside and industrial areas was explored. The findings revealed that relative water content showed a significant positive and negative correlation with leaf surface texture and leaf surface area. On the other hand, ascorbic acid showed a significant positive correlation with them. In conclusion, it has been studied that morphological parameters including biochemical parameters can be proved to be important in investigating the ability of plants to cope with air pollution and in calculating tolerance index.

Detect urban trees air pollution sensitivity & tolerance by leaf trait analysis in the industrial zone of Kumaun Himalaya Uttarakhand India

The plant absorbs gases and particulate matter through its leaves and contributes to cleaning the atmospheric pollutants. Sensitive plant species act as bioindicators of air pollution, while tolerant species are sinks of air pollutants. However, in ecologically sensitive regions like the Himalayas, there are no guiding rules for the selection of roadside plants for urban development due to a lack of scientific research. To address this, this study aimed to identify roadside plant species sensitivity and tolerance to air pollution near the industrial hub Rudrapur located in Kumaun Himalaya using the Air Pollution Tolerance Index (APTI). The APTI is used as a tool for evaluating and categorizing plants according to their levels of tolerance or sensitivity to air pollutants. In this study, the APTI of five plant species has been measured. A One-Way ANOVA was conducted to assess variations in biochemical parameters of five chosen roadside plant species situated at two distinct sites. Mangifera indica and Nerium species were recorded with high APTI values, indicating their tolerance to air pollution. However, the Eucalyptus species was identified as the most sensitive species with low APTI. Selecting suitable tree species to combat air pollution can improve the urban environment.

Evaluation of the effects of dust pollution on specific plant species near and around the marble mining site in Rajasthan, India.

Airborne particles (dust pollution) pose a significant threat to both human and plant populations. Plant leaves act as crucial biofilters, capturing significant amounts of air pollution; this characteristic offers a valuable tool to measure local pollution levels and assess individual plant species' ability to intercept and mitigate harmful dust particles. The present study was carried out to asses the effect of responses of various plant species to dust pollution near and around the marble mining site comprising residential site, highway area, and Central University of Rajasthan as control. The anticipated pollution index, air pollution tolerance index (APTI), dust absorption capacity, metal accumulation index (MAI), and biochemical factors were used to evaluate plant responses. Azadirachta indica A. Juss. demonstrated the highest (29.0) and Vachellia nilotica L. showed lowest (5.6) APTI, respectively. A. indica showed maximum MAI values in comparison to other plant species situated at residential site. Additionally, monitoring of particulate matter (PM10) observed to highest at highway, followed by mining, residential, and control sites. Overall A. indica representing highest APTI and effective dust capturing capacity at all sites could serve as potential pollution sinks. V. nilotica, with its very low APTI, can be marked as biomonitoring tool for detecting dust pollution.

Air Pollution Tolerance of Several Species of Trees in the Petrochemical Industry Area Using Air Polution Tollerance Index (APTI) Method

The petrochemical industry is fertilizer industry factories whose production can have an impact on air quality. The industrial area has decreased environmental quality caused by air pollution. Air pollution comes from factory activities as well as motor vehicle fumes and forest burning. The decline in air quality is characterized by the accumulation of pollutant particles in the air. Spesies tree planting in the Petrochemical industry area aims to reduce air pollution. Trees that are able to withstand air pollution stress conditions are categorized as tolerant species. This study aims to determine the tolerance to air pollution by analyzing the Air Pollution Tolerance Index (APTI). Determination of the sampling is done by convinience sampling method with several sample criteria. The results showed that the APTI value of Filicium decipiens Wieght & Arn. (Fern Leaf Tree) was 5.08, Swietenia macrophylla King (Baywood) 5.62 and Mimusops elengi L. (Spanish Cherry) 5.93. This study shows that in the Petrochemical industry area, F. decipiens is categorized as a sensitive species, while S. macrophylla and M. elengi are categorized as moderately tolerant to air pollution based on tolerance category in Thakar and Mishra (2010).

Impact of automobile exhaust on biochemical and genomorphic characteristics of Mimusops elengi L. growing along roadsides of Lahore city, Pakistan

Automobile exhaust releases different types of pollutants that are at great risk to the air quality of the environment and incidental distress to the nature of roadside plants. Mimusops elengi L. is an evergreen medicinal tree cultivated along the roadside of Lahore City. This research aimed to investigate physiological, morphological and genomorphic characteristics of M. elengi under the influence of air pollution from vehicles. Healthy and mature leaves were collected from trees on Canal Bank and Mall roads of Lahore as the experimental sites and control sites were 20 km away from the experimental site. Different physiochemical, morphological, air pollution tolerance index (APTI) and molecular analysis for the detection of DNA damage were performed through comet assay. The results demonstrated the mean accumulated Cd, Pb, Cu and Ni heavy metal contents on the leaves were higher than the control plants (1.27, 3.22, 1.32 and 1.46 μg mg−1). APTI of trees was 9.04. Trees in these roads significantly (p < 0.01) had a lower leaf area, petiole length and leaf dry matter content in comparison to control site. Increased comet tail showed that DNA damage was higher for roadside trees than trees in the control area. For tolerance of air pollution, it necessary to check the APTI value for the M. elengi at the polluted road side of Lahore city. For long-term screening, the source and type of pollutants and consistent monitoring of various responses given by the trees should be known.

Greenery planning for urban air pollution control based on biomonitoring potential: Explicit emphasis on foliar accumulation of particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs)

In this study, efficiencies of eight indigenous plants of Baishnabghata Patuli Township (BPT), southeast Kolkata, India, were explored as green barrier species and potentials of plant leaves were exploited for biomonitoring of particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs). The present work focused on studying PM capturing abilities (539.32−2766.27 μg cm−2) of plants (T. divaricata, N. oleander and B. acuminata being the most efficient species in retaining PM) along with the estimation of foliar contents of PM adhered to leaf surfaces (total sPM (large + coarse): 526.59−2731.76 μg cm−2) and embedded within waxes (total wPM (large + coarse): 8.73−34.51 μg cm−2). SEM imaging used to analyse leaf surfaces affirmed the presence of innate corrugated microstructures as main drivers for particle capture. Accumulation capacities of PAHs of vehicular origin (total index, TI > 4) were compared among the species based on measured concentrations (159.92−393.01 μg g−1) which indicated T. divaricata, P. alba and N. cadamba as highest PAHs accumulators. Specific leaf area (SLA) of plants (71.01−376.79 cm2 g−1), a measure of canopy−atmosphere interface, had great relevance in PAHs diffusion. Relative contribution (>90%) of 4–6 ring PAHs to total carcinogenic equivalent and potential as well as 5−6 ring PAHs to total mutagenic equivalent and potential had also been viewed with respect to benzo[a]pyrene. In−depth analysis of foliar traits and adoption of plant−based ranking strategies (air pollution tolerance index (APTI) and anticipated performance index (API)) provided a rationale for green belting. Each of the naturally selected plant species showed evidences of adaptations during abiotic stress to maximize survival and filtering effects for reductive elimination of ambient PM and PAHs, allowing holistic management of green spaces.

Morphological and biochemical changes in Quercus humboldtii in response to warmer and polluted urban areas in a tropical Andean city

Abstract The rapid growth of urban population has significantly changed human settlement patterns, leading to a decline in air quality and changes in climatic conditions in urban areas. Trees are recognized as nature-based solutions because they can remove particles from the air and regulate the climate. However, trees are negatively affected by pollution and temperatures, which represent a challenge for urban planning, management, and human health. To assess the impact of urban pollution and warmer climates on functional traits, we conducted a study using Quercus humboldtii, an endangered tree species endemic to Colombia and Panamá that dominates Andean forests and urban green areas in Bogotá. We selected three localities with contrasting pollution levels and climate conditions and measured 10 morphological and biochemical traits in six individuals at each location. Our findings revealed that Q. humboldtii adjusted morphological and biochemical traits in response to the environmental challenges posed by urban environments. The functional strategies varied between individuals with thin and large leaves and acidic pH in the colder and unpolluted native forest, while others displayed a conservative resource strategy (high leaf dry matter content) and neutral pH in the warmer and most polluted locality. Despite these differences, several traits indicate that Q. humboldtii is not a species tolerant to pollution. This is further supported by the air pollution tolerance index (APTI) values. Our results suggest that Q. humboldtii should be planted in areas of Bogotá with low pollution levels in order to promote its long-term survival and support ecosystem services.

Selection of tropical trees and shrubs for urban greening in coal mine complex: a case study of Singrauli, Madhya Pradesh.

An experimental investigation was conducted to determine the effectiveness of roadside trees for removing dust and the effects of dust load on the physiology and micromorphology of the foliage. The present study was conducted near an open coal mining complex situated in Singrauli, Madhya Pradesh, India, to assess the air pollution tolerance index (APTI), anticipated performance index (API), dust capturing capacity (DCC), and leaf morphology of trees and shrubs growing around the coal fields. Results showed that Azadirachta indica, Mangifera indica, Ficus religiosa, Ailanthus excelsa, and Ficus benghalensis were the most tolerant species towards air pollution (high APTI scores), while plants like Calotropis gigantea, Lantana camara, and Tectona grandis were proven to be bio-indicator species. Butea monosperma, Ficus benghalensis, Alstonia scholaris, and Terminalia arjuna were plant species with the highest DCC. Two-way ANOVA showed significant differences site-wise and season-wise in the biochemical parameters of APTI and a considerable difference site-wise with respect to dust capturing capacity. Correlation and regression analyses revealed a very high positive correlation between APTI and ascorbic acid value. The study recommends suitable plant species to manage rising air pollution in the coal mine and nearby areas apart from suggesting the development of a green belt.

Evaluation of tree species using Air Pollution Tolerance Index for urban landscaping in Delhi

Air pollution which negatively impacts both human health and the environment is a mountainous challenge before policymakers and city planners in urban areas. Urban landscaping with effective pollution-combating tree species is one of the soundest strategies to mitigate pollution adversaries. However, not all tree species are equally suitable for urban environments due to varying levels of tolerance to air pollution. This study has been designed to evaluate the physiological and biochemical responses of seven commonly occurring tree species in the Talkatora garden (TG) and Income Tax Office (ITO) representing non-polluted and polluted locations in Delhi, respectively applying Air Pollution Tolerance Index (APTI). The current research study was carried out during 2021–22 at the Division of Floriculture and Landscaping, ICAR-Indian Agricultural Research Institute, New Delhi. In tree species understudy, it was recorded that the pH of leaf extract, total chlorophyll, and relative water content was lower in the winter season than summer season except for the ascorbic acid. Ficus religiosa with the highest APTI value (23.23) followed by Pongamia pinnata (20.85) were found most tolerant tree species to air pollution in Delhi during the winter season at the polluted (ITO) and non-polluted (TG) location respectively with a reverse trend for the summer season. Polyalthia longifolia was found most sensitive (bioindicator plant) to air pollution among the seven trees under study owing to the lowest APTI values (11.14 and 12.58) across the seasons at non-polluted (TG) and polluted (ITO) locations respectively. Furthermore, Ficus religiosa with the highest APTI across the locations and seasons was assessed as the best performer, hence, could be the most efficient option for landscaping in polluted and non-polluted areas.

Assessment of Plants Sensitivity to Air Pollution using Physiological and Biochemical Parameters

Plants act as a main green belt enhancement component. Green plants create a surface that may absorb air pollutants and act as a sink for them, making greenbelts an efficient method of controlling air pollution. Thus attention is needed to promote and develop green belt zones in polluted areas. The current study is focused on evaluating the air pollution tolerance levels of Mangifera indica, Ficus religiosa, Psidium guajava, Annona squamosa already grown in polluted and unpolluted sites. By taking into account biochemical markers such as total chlorophyll level, ascorbic acid level, pH, water content, the Air pollution tolerance index (APTI) was calculated. APTI is an empirical relationship that assesses the degree to which different plant species can tolerate air pollution .Plants that possess APTI value less than or equal to 11 are known as sensitive, between 12 and 16 are moderately tolerant and greater than 17 are tolerant. The results obtained from the study showed that M. indica is more tolerant in nature. The rest of the plants used in the study are found to be intermittently tolerant. From this study, it can be concluded that planting Mangifera indica, Psidium guajava ,Annona squamosa, Ficus religosa in urban areas can reduce air pollution. This study also concludes that use of the APTI evaluation for the identification of air pollution tolerant plants is a suitable method.

Evaluation of air quality through various bioparameters near Valankulam lake, Coimbatore

Road and bridge construction close to lakes generates a lot of dust, which pollutes the air in that area. This is about the negative effects of vegetation activities. Some have the tolerance capacity, while others do not, leading to adverse effects. The study focuses on the air pollution tolerance index (APTI) of trees near Valankulam Lake in Coimbatore. Physiological and biochemical factors were employed to determine the APTI. The leaves of 19 trees were collected for the study and tested for ascorbic acid, total chlorophyll concentration, leaf pH, and relative water content. Albizzia lebbeck was found to have the highest tolerance value (88.81), followed by Ficus religiosa, Bougainvillaea spectabilis, Nerium oleander, Ricinus communis, Thevetia peruviana, Azadirachta indica and Tamarindus indica. Tectona grandis (8.01) is the most vulnerable to pollution, followed by Pongamia pinnata, Vitex negundo and Tecoma stans. According to the findings, the tolerant species can serve as a source, while the sensitive plants serve as a signal of pollution.

Assessment of air pollution tolerance index and anticipated performance index of roadside plants used for greenbelt development in the Kathmandu Valley, Nepal

The study emphasizes the significance of evaluating performance index of plants in urban vegetation. The performance of some common roadside plants like Ficus benjamina, Buddleja asiatica, Jacaranda mimosifolia, Cinnamomum camphora, and Callistemon viminalis were assessed for air pollution tolerance index (APTI) and anticipated performance index (API). The study was conducted in polluted site (Balkhu-Koteshwor road section) and control site (Godawari Botanical Garden) in the Kathmandu Valley, Nepal. The APTI values are 7.71–11.86 in the control site and 8.83–12.54 in the polluted site. Based on APTI, Ficus benjamina, Cinnamomum camphora and Jacaranda mimosifolia are intermediate tolerant, whereas Buddleja asiatica and Callistemon viminalis are sensitive to air pollution. The API values for Jacaranda mimosifolia and Cinnamomum camphora are better, indicating that they are good performers in terms of air pollution tolerance. In contrast, Buddleja asiatica is evaluated as poor performer among the selected plant species. Tolerant plant species hold the potential to serve as effective vegetative traffic barriers and contribute to urban green belts. Conversely, sensitive plants can be utilized as bio-indicators of air quality.

Roadside Automobile Stressed Plants as Bioindicator Based on Air Pollution Tolerance Index in Dhaka, Bangladesh

The evaluation of plants' ability to resist pollution was conducted by studying two distinct plant species, Swietenia mahagonia and Polyalthia longifolia, obtained near the urban roadsides in Dhaka during the winter season. The air pollution tolerance index (APTI) was assessed for both Polyalthia longifolia and Swietenia mahagoni. Between the two species, Polyalthia longifolia exhibited the highest air pollution tolerance index (APTI 12.54), indicating its lower sensitivity towards pollution. On the other hand, Swietenia mahagoni (APTI 12.27) demonstrated a comparatively higher sensitivity to pollutants. Polyalthia longifolia had the highest total chlorophyll concentration (TCC) (1.080 mg/g), relative water content (RWC) (88.50%), pH value (6.73), ascorbic acid concentration (ACC) (4.303). On the other hand, Swietenia mahagoni showed the lowest scores across almost all the indicators (except ACC: 5.44), demonstrating the most pollutant-sensitive species. The assessment of plants in relation to their capacity to withstand air pollution is crucial due to their role as a pollution sink. Consequently, planting species that exhibit tolerance to pollution in contaminated regions can provide several environmental advantages. Biodivers. Conserv. Bioresour. Manag. 2023, 9(2): 1-10

Assessment of air pollution tolerance potential of selected dicot tree species for urban forestry.

Air pollution is one of the killers of our age especially for the urban areas. Urban forestry which involves planting more trees has been considered as one of the prominent strategies to mitigate air pollution. Identification of trees tolerant to air pollution is important for plantation drives being organized across the country. The present study aimed to compare the air pollution tolerance potential of 46 tree species growing in Guru Nanak Dev University (GNDU) campus, Amritsar, using two indices, viz., Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). APTI is based on four biochemical parameters, viz., relative water content, leaf extract pH, total chlorophyll, and ascorbic acid contents of leaf samples, whereas API takes into consideration morphological and socioeconomic values of plant species along with their APTI. Based on APTI values calculated for 46 tree species, only 2 tree species, viz., Psidium guajava (46.26) and Cassia fistula (41.83), were found to be tolerant to air pollution, while 25 species showed intermediate tolerance. API scores revealed one tree species, namely, P. guajava, as an excellent performer, 8 species as very good performers, and 28 species as moderate to good performers against air pollution. In conclusion, tree species like Alstonia scholaris, C. fistula, Ficus tsjakela, Grevillea robusta, Kigelia africana, Mangifera indica, Melia azedarach, P. guajava, Pongamia pinnata, Pterospermum acerifolium, Putranjiva roxburghii, Syzygium cumini, Terminalia arjuna, and Toona ciliata can be considered as most desirable for plantations in areas around GNDU campus.

Environmental pollution biomonitoring around a cement factory based on the Air Pollution Tolerance Index of some tree species.

The present study examined the ability of Quercus castaneifolia C.A.M., Parrotia persica C.A.M., and Carpinus betulus L. for environmental pollution biomonitoring based on the Air Pollution Tolerance Index (APTI). Four leaf traits, total leaf chlorophyll content, leaf extract pH, ascorbic acid content, and relative water content of leaf, were used to compute the APTI values. The study was conducted at five sites in the Hyrcanian forests at different distances from a cement factory close to the Neka city, northern Iran. Based on the results, a 22.5, 30.1, and 25.8% decrease was thus recorded in total chlorophyll content for Q. castaneifolia, P. persica, and C. betulus, respectively, compared to the reference site. However, ascorbic acid content shows an increment of 179.8, 116.8, and 97.3% for P. persica, C. betulus, and Q. castaneifolia, respectively, in the polluted sites as compared to the reference site. The relative water content of P. persica was significantly higher than of Q. castaneifolia and C. betulus in all studied sites. APTI was significantly different among the species, and P. persica was highly tolerant to air pollution, with the highest values of APTI ranging from 11.8 to 16.9. The APTI values of Q. castaneifolia ranged from 9.5 to 11.3 and showed an intermediate tolerance to air pollution. Also, the most sensitive species to air pollution was C. betulus, with a range of 6.6-7.9 in APTI values. Based on APTI values, it can be suggested that P. persica can be used as a biomonitor, while C. betulus can be used as a bioindicator for atmospheric dust deposition and heavy metal pollution.

Complex study of air pollution based on tree species in Vienna

Plants are especially useful as biological indicators to assess air pollution and the effects of urbanisation. The aim of this study was to investigate tree species’ sensitivity to air pollution using the Air Pollution Tolerance Index (APTI), the dust content (PM10) of leaves, and the heavy metal concentration of leaves. Sampling sites were in a city park (urban area), a location on the edge of the city (suburban area), and a forested location (rural area) along an urbanisation gradient in the city of Vienna in Austria. Leaf samples were collected from Acer platanoides, Fraxinus excelsior, and Quercus robur tree species. The APTI was determined by measuring the content of relative water ascorbic acid and chlorophyll, and the pH of leaf extracts. We found significant difference among species in their relative water content, pH, and content of ascorbic acid and chlorophyll Additionally, we found significant differences in chlorophyll content and pH based on sampling site. The highest chlorophyll content was found in A. platanoides. There was a significant difference among species in Al, Ba, Cr, Ni, and Zn concentrations in each stage of urbanisation. Based on APTI values, the studied species were sensitive indicators of air pollution; thus, they are useful bioindicator species, and they are suitable for air pollution monitoring. We demonstrated the effects of urbanisation with these bioindicator species with elevated PM10, Al, Ba, Cu, Fe, Sr, and Zn concentrations in urban area samples.Graphical abstract

Identifying pollution scavenging potential of perennial plants growing in Maitreyi College Campus, University of Delhi

Aim: Air Pollution Tolerance Index (APTI) represents the potential of a plant to combat air pollution. In the present study, APTI value of 77 perennials growing in the Maitreyi College Campus, New Delhi was calculated, and these plants were classified into tolerant and sensitive species. Methodology: APTI was calculated by assessing four physiological and biochemical parameters, pH, Relative Water Content (RWC), Total Chlorophyll (TCh), and Ascorbic Acid (AA). Results: The highest APTI was observed in Musa sp. (10.52) indicating it to be the most tolerant, while the lowest in Aegle marmelos (1.93), showing it to be the most sensitive for pollution. Results showed Musa sp., Salmelia sp., Terminalia arjuna, Murraya exotica, Hamelia patens, Ravenala madagascariensis, Ficus racemosa, Cascabela thevetia, Eugenia uniflora, Nyctanthes arbortristis to have good potential in reducing air pollution in a sustainable manner. Species such as Aegle marmelos, Plumeria rubra, Dracaena, Carissa carandas, Eucalyptus sp. were sensitive to air pollution. Interpretation: Analysis of results suggested the importance of APTI analysis in a campus for cataloging the pollution tolerant and sensitive plants. The pollution tolerant plants could be used for the green belt formation, while plants, which are sensitive to pollution can be used as an indicator of pollution. Moreover, mapping and compilation of information of trees (deciduous and evergreen) and shrubs growing in the campus helped in documenting the rich flora of the campus with pollution tolerance potential. Key words: Air Pollution, Air Pollution Tolerance Index, Air quality, Trees

Air pollution tolerance index of Persea bombycina: Primary food plant of endemic muga silkworm (Antheraeaassamensis)

Air pollution poses a significant threat to human health, ecosystems, and the livelihood of tribal communities. This study focuses on understanding the impact of air pollution on the primary food plant som (Persea bombycina Kost.) of the endemic Muga silkworm (Antheraea assamensis) and its implications for muga silk production. The study was conducted at two sites in northeastern India, one free from atmospheric pollutants (FAP) and the other affected by pollution from an oil refinery (PAS). Various atmospheric pollutants, including particulate matter, hydrocarbons, and heavy metals, were found to be higher at the PAS site. The study investigated biochemical parameters like ascorbic acid, relative water content, total chlorophyll, and extractable pH in the leaves of P. bombycina to determine its air pollution tolerance index (APTI). Results showed that the ascorbic acid content in the leaves increased significantly at the PAS site (p < 0.05), indicating the plant's adaptation to air pollution stress. Similarly, the APTI values were higher during summer compared to winter, suggesting better tolerance during the former season. Positive correlations were found between APTI and ascorbic acid content (p < 0.05), emphasizing the role of ascorbic acid as an antioxidant in mitigating the effects of air pollution. The study highlights the importance of understanding the tolerance levels of P. bombycina to develop protective measures for sustaining Muga silk production in the face of rapid industrialization and increasing pollution. This research can aid policymakers in balancing economic growth with environmental conservation and protecting traditional practices of tribal communities.

A GIS-Based Assessment of Land Cover Changes and Tree Species Suitability for Urban Greening Policies in the City of Kitwe, Zambia

Study objective and design A change vector analysis (CVA) was used to determine land cover (LC) changes and identify tree species that are best for urban greening based on carbon sequestration and air pollution. The study assessed LC change in Kitwe, Zambia, from 1990 to 2015. This study identified the most planted urban tree species along Kitwe’s main roads and highways and evaluated typical urban tree species’ pH, RWC, total chlorophyll, ascorbic acid, and biomass. Place and length of study The urban trees in Kitwe, Zambia, make up the study population. The city of Kitwe is a thriving centre for mining and commercial activities and is situated in Zambia’s Copperbelt Province. The investigation took place during 2018 and 2019. Methodology The NDVI and BSI indices were created using spectral indices created from Landsat images of Kitwe taken in 1990 and 2015, respectively. The size and direction of the LC were then determined using CVA, and a district database of land cover changes was constructed using GIS. Urban trees from the built-up area were utilised to create an inventory of common urban tree species based on the land cover classification. The anticipated performance index (API), which measures the suitability of tree species for improving air quality, and the air pollution tolerance index (APTI), which measures the suitability of tree species for urban greening, are two of the three assessment methods that were employed. In addition, above-ground biomass (AGB) was employed to quantify the carbon sequestration contribution of the current urban forest. Results The study discovered that between 1990 and 2015, mining activity and urban growth in Kitwe both contributed to changes in the area’s LC. While the central business district still exhibits a persistent presence as a result of the town’s age, having sprung up before the 1990s with more expansions in the new areas, areas being monitored showed low and medium change intensity, mostly in the northeast of the district. In the current investigation, there was a significant difference in the relative abundance of species (p = 0.05). In the study site, Mangifera indica (RA = 12.3%) and Delonix regia (RA = 15.9%) were the two most prevalent species. According to the study, eleven species were found, and each has accumulated carbon in a unique way throughout time depending on its allometry and age. These distinctions in physiological response (tolerance) to air pollution are noteworthy. Bauhinia variegata, Toona ciliate, Gmelina arborea, Eucalyptus grandis, and Delonix regia were all identified as suitable tree species. Conclusion Over the past 25 years, more than 50% of the land cover has changed, with the majority of that change occurring in regions that are now classified as built-up areas. The majority of Kitwe’s urban forests are found in the populated areas and are made up of a variety of ornamental trees that are frequently cultivated for their aesthetic value, attractiveness, and shade. According to the research, this mixture also includes opportunistic urban trees (invasive species) and fruit-bearing trees intermingled with native species. Overall, this study suggests the following species: For urban trees suited for greening programmes aimed at improving air quality and providing shade and beauty in green areas, residences, and sidewalks that have a low air pollution environment, consider Bauhinia variegata, Toona ciliate, Gmelina arborea, Eucalyptus grandis, and Delonix regia.

Assessing the air pollution tolerance index (APTI) of trees in residential and roadside sites of Lahore, Pakistan

Industrialization and extensive use of automobiles cause air pollution which indicates the inability of trees plants due to changes in their biochemical and physiological processes for absorbing the air pollutants. Air Pollution Tolerance Index (APTI) is an important indicator for determining the ability of trees plants for their efficient ability for controlling air pollution. To estimate it and its effects a comparitive study of the air pollution tolerance index was examined in 14 species of plants between residential areas (University of the Punjab) and roadside areas (orange train line). To calculate the APTI value, four physiological and biochemical parameters—ascorbic acid, relative water content (RWC), pH, and chlorophyll concentration of leaf samples—were integrated. Present study results reveal that the plant tolerance against pollution is site specific, and that integrating a number of biochemical parameters give more accurate results as compared to single. Results show that Alstonia scholaris show maximum and Magnifera indica show minimum APTI values in residential areas while Magnifera indica shows maximum and Bougainvillea glabra shows minimum APTI value in roadside areas. Present study results show that plants with higher APTI values are tolerant of pollution, whereas those with lower APTI values are susceptible to it. Thus Plants with more APTI values are tolerant and use as a sink to control pollution in urban and industrial sites.