Work

Tree shade protection factors by Jacaranda mimosifolia: a summertime comparison of UV dosimetry and whole sky image analysis for residential urban environments

Year: 2025

Type: article

Abstract: This study aims to characterize Jacaranda mimosifolia in Queensland as a shade protection species for residential urban environments during peak summertime ultraviolet exposure periods, assessed near solar noon and taking into account changes in tree aspect measured relative to the main trunk and with variation in seasonal foliage. Ultraviolet polysulphone dosimeters and whole sky image (WSI) analysis was employed to derive site protection factors (PF) measured on the north, south, east and western sides of trees planted alongside urban street locations in southern Queensland, Australia for the summer months of December, January and February. Dosimetry and WSI analysis of the site PF measured in 5-minute intervals one hour before and following noon confirmed there is a seasonal variation in protection from ultraviolet radiation due to the presence of Jacaranda mimosifolia . Site PF varied from 2 to 12 with protection peaking at the end of summer when canopy foliage is greatest. Protection factors were shown to follow a monthly cycle confirming observed patterns in critical daytime PF either side of noon for the same species derived previously in research from southern Australia.

Source: Urban forestry & urban greening

DOI: 10.1016/j.ufug.2025.129260