Building Proximity and Height Are Associated with Tree Growth, Crown Structure, and Allometric Relationships in the Arid City of Jericho

Building proximity was associated with species-specific patterns in urban tree growth, crown structure, and allometric relationships under arid conditions. Urban trees provide essential ecosystem services in arid cities, yet the extent to which surrounding buildings influence tree development remains insufficiently understood. This study investigated species-specific responses of urban trees to surrounding urban structures in Jericho, Palestine, using a height-weighted Building Proximity Index (BPIsum) integrating building distance and height. Tree structural variables and aboveground carbon storage were assessed for Delonix regia, Ficus nitida, and Phoenix dactylifera. Linear mixed-effects models and linear models were used to evaluate growth responses and allometric relationships across the BPIsum gradient. Positive BPIsum associations were observed for stem diameter and aboveground carbon storage in F. nitida (β = 0.101, p = 0.011; β = 0.236, p = 0.004, respectively). In contrast, P. dactylifera maintained stable structural characteristics, whereas D. regia exhibited intermediate responses. Crown diameter and crown symmetry remained stable, whereas crown volume showed stronger species-specific variation. These findings highlight species-specific patterns of tree development and have implications for species selection and urban greening strategies in arid cities.