At present, urban planners select tree species for urban plantation based on the size, aerodynamic properties, the aesthetic value of trees and the tree's air pollution tolerance and rank choices based on an anticipated performance index (API). The index does not consider whether the chosen species will aggravate the pollution by emitting highly reactive ozone or secondary aerosol precursors or allergenic pollen. In this study, we introduce a new Air Quality Impact Index (AQII) which ranks choices in a more holistic manner, by taking aerodynamic properties, leaf structure, pollution uptake potential, pollution tolerance, ozone and aerosol precursor emissions, and the pollen allergy impact into account. We demonstrate the advantage of the AQII ranking by evaluating the impact of two species with equally high API that rank on the opposite ends of the AQII scale on urban air quality during summer season. We review the literature to compile a list of 149 species out of 280 tree species, which are commonly considered for urban plantation, for which VOC emissions have been reported. We also compile the allergy potential (107) and air pollution tolerance and calculate the AQII for 98 species, for which sufficient data is available.
Bibliographical noteFunding Information:
We thank the IISER Mohali Atmospheric Chemistry Facility for data and the Ministry of Human Resource Development (MHRD), India, and IISER Mohali for funding the facility. V.P. acknowledges DST Inspire fellowship, A.K., A.C. and H.H., acknowledge MHRD and IISER Mohali for JRF/SRF fellowships, and S.D. acknowledges University Grants Comission (UGC) for SRF fellowship. A.S. acknowledges MHRD and IISER Mohali for postdoctoral fellowship. We acknowledge the DST Climate Change Program (SPLICE) DST/CCP/MRDP/100/2017(G) for funding support towards sampling and fieldwork for plant chamber experiments. We thank all past and present members of the group for technical assistance with leaf porometer and plant chamber measurements.
© 2021 Elsevier B.V.
- Pollen allergy
- Population exposure
- Urban air quality
- Urban vegetation impacts