Summer‑time performance of urban tree and shrub species as particulate matter biofilters: a case study on species‑level tolerance and PM accumulation in Malda, Eastern India

Urbanization has emerged as one of the most dynamic trends, which acts as a catalyst for economic development while posing pressing environmental challenges. Among them, air pollution poses a significant threat to public health and ecosystem. This study evaluated the particulate matter (PM) accumulation and pollution tolerance among ten abundant tree and shrub species across four sites with varying pollution gradients during summer time in Malda, West Bengal, India. Total PM carrying capacity, segregation of surface and in-wax PM, epicuticular wax, and biochemical parameters were evaluated. The air pollution tolerance index, anticipated performance index, and a newly integrated the revised anticipated performance index were calculated to evaluate species tolerance to pollution. Results revealed that Ficus benghalensis, Ricinus communis, and Alstonia scholaris exhibited higher PM accumulation and tolerance, indicating their potential for greenbelt development. In contrast, Bougainvillea spectabilis showed sensitivity toward pollution. Principal component analysis indicated that plant responses were more strongly associated with site-specific environmental conditions than with species-specific traits. This research aims to provide a baseline for strategic plant selection and urban vegetation planning, which are essential for constructing sustainable cities. The planting of tolerant species in urban landscapes represents a practical and cost-effective approach for improving air quality.