Rainfall partitioning and cloud water interception in native forest and invaded forest in Hawai'i Volcanoes National Park

Invasive tree species significantly alter rainfall partitioning and cloud water interception (CWI) in Hawaiian forests, potentially impacting water resources. A study comparing native Metrosideros polymorpha and invasive Psidium cattleianum forests in Hawai'i Volcanoes National Park found that while the invaded site had higher stemflow (1091 mm annually), the native forest exhibited greater canopy storage capacity (1.86 mm vs. 0.85 mm) and CWI (1188 mm vs. 734 mm). Despite being located farther from orographic clouds, the native forest intercepted more cloud water, suggesting structural advantages in harvesting droplets. However, invasive species reduced net rainfall reaching the ground (110% of rainfall vs. 123%), posing risks to groundwater recharge and aquatic ecosystems.

Takahashi, M., Giambelluca, T. W., Mudd, R. G., DeLay, J. K., Nullet, M. A., & Asner, G. P. (2010). Rainfall partitioning and cloud water interception in native forest and invaded forest in Hawai’i Volcanoes National Park. Hydrological Processes, 25(3), 448–464. Portico. https://doi.org/10.1002/hyp.7797