Stemflow has distinguishable effects on the hydrology and biogeochemistry of forest ecosystems. Nontheless, the hydrologic process of stemflow is still poorly understood. Stemflow production of evergreen broadleaved trees (C. cuspidata), deciduous broadleaved trees (B. platyphylla, Q. crispula, B. ermanii) and coniferous trees was monitored on event-basis in the forests of central Japan. Aimed to identify major controlling factors and the temporal variability of stemflow generation, and to compare the stemflow DOC dynamics in relation to tree species and size.
Stemflow percentage of incident rainfall and funneling ratio (FR) decreased with increasing rainfall intensity in a logarithmic function. The stemflow generating in evergreen broadleaved species was larger than that in deciduous broadleaved species. Comparing stemflow percentage and FR in different DBH classes of C. cuspidata, higher stemflow percentage and FR occurring in the smaller trees, due to the small trees grow towards the light and develop upright braches which are effective in funneling rainfall. Furthermore, higher DOC concentrations were found in Q. crispula and coniferous trees likely being attributable to the differences in bark texture. Nevertheless, higher DOC flux wasn’t observed in Q. crispula, but in C. cuspidata which with lower DOC concentration, because of the different stemflow volume. These results suggested that the stemflow generation is the results of a complex set of interactions among rain event characteristics, tree species, and tree size.