How do trees capture traffic pollution? How they affect the ventilation in street canyons? These questions have started to become of interest to urban air quality research. However, trees may also affect the atmospheric chemistry and air quality through volatile organic compounds (VOCs). Trees release these compounds - which constitute the odours of the forest – as a part of their normal functioning, but in particular in stress situations.
In this project, we quantify the VOC emissions of tree species that are common in Montreal by measuring the VOC emissions from the canopies of established urban trees. Then, we analyse the effects of the tree VOCs on urban air quality using atmospheric chemistry models, focusing on ozone and aerosol concentrations. With this, we aim to answer two questions 1) how much the potentially stressful urban environment affects the VOC emission rates of common urban tree species and 2) whether the VOC emissions of trees can impact the air quality in an important way.
