Reimagining Urban Stemflow: How Tree Traits Shape Rainfall Redistribution in Peri-Urban Environments

Area of Science:

• Urban hydrology
• Ecohydrology
• Forestry

Background:

• Urban trees significantly influence the integrated ecohydrology of water-forest-soil systems.
• Understanding vegetation traits is crucial for managing urban water cycles, including rainfall interception, runoff, and infiltration.
• Anthropized areas benefit from improved water management through strategic tree selection.

Purpose of the Study:

• To investigate the relationship between dendrometric and morphological tree traits and stemflow yield in urban environments.
• To identify key tree characteristics that influence water redistribution in peri-urban areas.
• To inform urban forestry practices for enhanced water management and city resilience.

Main Methods:

• Measured stemflow volumes across 58 rainfall events for eight common peri-urban tree species.
• Analyzed dendrometric traits (size, height, crown area, basal area) and morphological traits (crown density, shape, trunk tortuosity, inclination, bark texture, bryophytes).
• Employed linear regression and factor analyses to determine trait-stemflow relationships.

Main Results:

• Trunk structure, crown shape, and bark texture were major drivers of stemflow yield.
• Exfoliating-bark species efficiently channeled water; species with large or inclined canopies had lower stemflow.
• Trunk inclination and bark morphology proved more reliable predictors of stemflow than basal area.

Conclusions:

• Tree selection for urban areas should prioritize traits that enhance water infiltration and reduce peak runoff.
• Integrating morphological and dendrometric parameters in urban forestry is vital for ecohydrological management.
• Findings support developing resilient urban landscapes aligned with sustainability targets (SDGs 6 and 11).