Abstract Background This study compared the phenotypic traits and microclimate parameters of street trees as affected by species origin (native N vs. non-native NN) and location (inside vs. outside the University of the Philippines, Los Baños UPLB). Methods Tree traits were counted and measured using a meter tape and a range finder, while microclimates (air temperature, relative humidity, heat index, light intensity) under tree canopies and adjacent exposed areas were gathered using a multifunctional environmental meter and a light meter. Results T-test analysis revealed that tree traits differed significantly but not in terms of microclimate, except for crown-shaded light intensity, with NN trees showing a significant reduction compared to N trees. Meanwhile, tree traits as affected by location showed significant variation only in the number of major branches, with trees outside UPLB registering more branches than the other location. Moreover, multiple linear regression indicated which part of the trees had a strong influence on crown-shaded microclimate, while results of correlation analysis showed that phenotypic traits, except for the relationship between total height and crown traits, regardless of their species’ origin, were significant, positive, and strongly correlated. Conclusions T-test analysis highlighted that street trees in solitary and/or small aggregates tend to enhance the production of protective (e.g., leaves) rather than productive (e.g., stems) traits, while correlation analysis suggested that interventions (e.g., pruning) could improve the trees’ crown-shaded microclimate condition. These findings could provide technical guidance for a more sound decision for the inclusion or removal of street trees in urban areas.
Piñon et al. (Thu,) studied this question.