Trees in the street canyon environment: exposure and response under changing micro-climates and water availability
This study investigates the potential influences of changing urban environmental conditions on tree function and health. Using the model MAESPA to represent an individual tree, we explore the influence of the unique urban environment (e.g. changing radiation levels, temperature, VPD, CO2) on tree transpiration and shading capacity. The model is tested with data collected from trees in a shallow street canyon in Melbourne, Australia. Within canyon environmental parameters such as radiation and CO2 concentrations were collected, as well as soil moisture, and the MEASPA model outputs are compared with observed leaf assimilation rates and stomatal conductance.
We then undertake a number of scenarios focussed on changing environmental conditions and/or soil moisture to explore the impacts on individual tree transpiration rates and canopy density and infer potential cooling benefits. Such information can help guide irrigation management of street trees under extreme heat conditions, and help inform street tree planting arrangements to maximise within canyon human thermal comfort.