Jamal Rushna, Narayan Shiv, Dubey Raghvendra, Kannaujia Rekha, Rai Richa, Behera Sandip K, Behera Soumit K, Shirke Pramod A, Pandey Vivek, Barik Saroj K
Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India.
Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002.
Environ Monit Assess. 2022 Dec 27;195(1):238. doi: 10.1007/s10661-022-10713-5.
Tropospheric ozone (O) has become one of the main urban air pollutants. In the present study, we assessed impact of ambient and future ground-level O on nine commonly growing urban tree species under Free Air Ozone Enrichment (FAOE) condition. During the study period, mean ambient and elevated ozone (EO) concentrations were 48.59 and 69.62 ppb, respectively. Under EO treatment, stomatal density (SD) significantly decreased and guard cell length (GCL) increased in Azadirachta indica, Bougainvillea spectabilis, Plumeria rubra, Saraca asoca and Tabernaemontana divaricata, while SD increased and GCL decreased in Ficus benghalensis and Terminalia arjuna. Proline levels increased in all the nine plant species under EO condition. EO significantly reduced photosynthetic rate, stomatal conductance (gs), and transpiration rates (E). Only A. indica and N. indicum showed higher gs and E under EO treatment. Water use efficiency (WUE) significantly increased in F. benghalensis and decreased in A. indica and T. divaricata. Air Pollution Tolerance Index (APTI) significantly increased in Ficus religiosa and S. asoca whereas it decreased in B. spectabilis and A. indica. Of all the plant species B. spectabilis and A. indica were the most sensitive to EO (high g and less ascorbic acid content) while S. asoca and F. religiosa were the most tolerant (lowg and more ascorbic acid content). The sensitivity of urban tree species to EO is a cause of concern and should be considered for future urban forestry programmes. Our study should guide more such studies to identify tolerant trees for urban air pollution abatement.
对流层臭氧（O）已成为主要的城市空气污染物之一。在本研究中，我们评估了在自由空气臭氧富集（FAOE）条件下，当前及未来地面臭氧对九种常见城市树木的影响。在研究期间，平均环境臭氧浓度和升高的臭氧（EO）浓度分别为48.59 ppb和69.62 ppb。在EO处理下，印楝、叶子花、鸡蛋花、无忧花和印度狗牙花的气孔密度（SD）显著降低，保卫细胞长度（GCL）增加，而孟加拉榕和印度榄仁的SD增加，GCL降低。在EO条件下，所有九种植物的脯氨酸水平均升高。EO显著降低了光合速率、气孔导度（gs）和蒸腾速率（E）。只有印楝和印度楝在EO处理下表现出较高的gs和E。水分利用效率（WUE）在孟加拉榕中显著增加，而在印楝和印度狗牙花中降低。空气污染耐受指数（APTI）在菩提树和无忧花中显著增加，而在叶子花和印楝中降低。在所有植物物种中，叶子花和印楝对EO最敏感（高气孔导度和低抗坏血酸含量），而无忧花和菩提树最耐受（低气孔导度和高抗坏血酸含量）。城市树种对EO的敏感性令人担忧，在未来的城市林业计划中应予以考虑。我们的研究应指导更多此类研究，以识别用于减少城市空气污染的耐受树木。
