Forest Canopy Interception Loss Across Temporal Scales: Implications for Urban Greening Initiatives

摘要

Increasing urban forest canopy coverage due to greening initiatives requires watershed managers to balance societal water practices with forest hydrological processes. One such process, canopy rainfall interception, can remove substantial portions of precipitation from catchments by simply intercepting, storing, and evaporating meteoric water. We performed a field study examining interception losses across temporal scales comparing two landscaping species of contrasting crown structures (Fagus grandifolia Ehrh., American beech, and Liriodendron tulipifera L., yellow poplar), native to the highly urbanized northeastern United States, to highlight the effect of landscape design on urban water and storm water management. Results show that landscape designs using the rougher bark texture, lower branch inclination, and thinner canopy of L. tulipifera can increase water losses during rainfall and, therefore, can be used to improve storm water management. On the other hand, the smoother bark, higher branch inclination, and deeper canopy of F. grandifolia decreased water losses, allowing greater water transfer to the surface or subsurface. Thus, interception-related water resource losses during urban forestry projects can be manipulated to benefit urban sustainability efforts if designers consider the multifaceted ramifications of planting different tree species with differing canopy structures.