In-situ spectroscopy and shortwave radiometry reveals spatial and temporal variation in the crown-level radiative performance of urban trees

In conventional microclimate environment modelling, and the development of tree planning strategies for urban heat mitigation, crown surface albedo any given species is assumed to be a constant. However, our recent research into radiative performance at level implied that changes over time. Based on in-situ spectroscopy protocols established previously measure transflectance, variation in characteristics was explored combining solar shortwave radiometry. Three commonly planted native UK species, Carpinus betulus, Acer campestre, Taxus baccata, were sampled. Spatial distribution profiles transflectance measured fixed altitudes normalised by spectroradiometry. Tree near infrared (NIR) region found proportionally linked albedo. Within each mean NIR 800–900 nm approximately 2.5 times It further radiation (700–2500 nm) accounted more than 90% total transflected from crowns. The results demonstrate linearly increases with momentary altitude maximum corresponds noon sunny days summer. across tends strongly dependent leaf size if considering visibly dense foliage. Our findings provide important insights shading effects resulting temporal albedo, consequences modelling mitigation strategies.