Evaluating dominant tree species as bioindicators for urban air pollution mitigation in Ranchi, Eastern India

Abstract

Key message: Effective nature-based solutions for urban air pollution require understanding how season, site, and species affect tree tolerance. The complex interplay of biochemical parameters significantly impacts trees’ sensitivity and tolerance. Abstract: Evaluating dominant tree species as bioindicators can provide valuable insights for effective air pollution mitigation strategies in rapidly developing cities like Ranchi, Eastern India. The air pollution tolerance index (APTI), anticipated performance index (API), and dust capturing capacity (DCC) of dominant urban street trees in Ranchi were studied at control, heavy traffic, and industrial sites during pre- and post-monsoon seasons. APTI varied significantly across seasons (F<inf>1,25.43</inf> = 27.24, p < 0.05), sites (F<inf>2,261.87</inf> = 280.50, p < 0.05), and trees (F<inf>9,9.18</inf> = 9.83, p < 0.05). APTI values were highest at industrial, followed by heavy traffic, and lowest at control sites. AA content was the most influential biochemical parameter associated with APTI, showing a statistically significant strong correlation (r = 0.819, p < 0.01). Street trees at industrial sites exhibited the highest APTI values (range: 15.11–19.99), followed by heavy traffic sites (12.79–18.30), and lowest at control sites (11.46–15.72). DCC also varied significantly across seasons (F<inf>1,0.321</inf> = 17.40, p < 0.05), sites (F<inf>2,2.65</inf> = 144.25, p < 0.05), and trees (F<inf>9,2.95</inf> = 160.92, p < 0.05). The highest DCC was recorded in Melia azedarach (2.64 mg cm−2), followed by Bauhinia variegata (2.49 mg cm−2), and Bridelia retusa (2.13 mg cm−2). APTI, API, and DCC were significantly affected by seasons, sites, species, and their interactions with pollutants. These findings highlight the importance of APTI, API, and DCC as important indicators of the pollution mitigation abilities of different urban street trees to recommend for urban greening initiatives in rapidly urbanizing cities like Ranchi. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.