Abstract
This study was conducted to compare seasonal and inter-plot differences in stemflow, throughfall, and interception loss from two deciduous broad-leaved forests in temperate region and to understand how the different stand structures influence rainfall partitioning. Seasonal stemflow and throughfall were greater in winter than in summer in both stands, as the fewer amount of leaves allowed increased direct rainfall to the trunk and forest floor. Tree diameter (or basal area) at breast height (DBH) was the cause of the difference in stemflow between stands. It was shown that an exponential relationship existed between the respective constant a and b in regression (Y=aX-b, where Y and X are stemflow and rainfall, respectively) obtained from each sampling tree and its DBH. Throughfall in Yamashiro site, which had lower stand density and basal area, was about 15% greater than that in Shirasaka site during both seasons. Interception loss in both stands showed seasonal and inter-plot variations, which can be primarily explained by the structural differences in their canopies. The site of Yamashiro gave a lower interception than that at Shirasaka during both seasons because the lower leaf area index (LAI) of Yamashiro, which caused a lower evaporation rate and lower canopy storage capacity.
