Understanding the physiological and biophysical response of urban roadside plantations for assessing adaptation and mitigation mechanisms toward vehicular emissions

The plants follow various strategies for adapting and mitigating climatic and environmental stresses. This offers an opportunity to comprehend adaptation and mitigation mechanisms under changing climate and environment emerging from vehicular emissions. We deployed an approach, i.e., physiological (Phy) and biophysical (Bioph) functional traits (FTs) based approach to understand plant response for assessing adaptation and mitigation potential for offsetting long-term urban climate and environment. We investigated Phy and Bioph FTs of adaptation, especially transpiration rate (E), stomatal conductance (Gs) and resistance (SRes), water use efficiency (WUE), carboxylation efficiency (CE), mesophyll efficiency (ME), leaf thickness (LTh), and mitigation FTs, including CO2 assimilation rate (A), leaf dust retention efficiency (DRE), and cooling impacts (CI) of the roadside plantation (Delonix regia and Callistemon viminalis). The study reported the significant effects of the roadside urban environment on the modulation of FTs, one of the strategies that plants follow to adapt and mitigate the urban climate. The C. viminalis was reported as having a better adaptive nature with higher mitigation potential than the D. regia. It is advocated that the approach deployed in the study could be exploited for identifying more adaptive plantation species to develop urban green belts for mitigating urban climate and environments.