Abstract: To provide basic hydrological data for sustainable management of south subtropical forest plantations, we measured rainfall, throughfall and stemflow in a 34year old Castanopsis hystrix stand in Guangxi Youyiguan Forest Ecosystem Research Station from January to December 2017. The results showed that total annual rainfall was 945.9 mm, with throughfall, stemflow and canopy interception accounting for 43.9%, 0.5% and 55.6% of total rainfall, respectively. The minimum rainfall that produced throughfall and stemflow was 0.6 and 3.8 mm, respectively. Rainfall had seasonal fluctuation, with the penetration rate being the lowest in summer and the highest in winter, and the stemflow rate and canopy interception rate showing opposite pattern. Small and short rainfall events led to low net rainfall input and high canopy interception. Among the four rainfall factors (rainfall amount, rainfall intensity, rainfall duration, and pre-rain drying period), rainfall amount had the strongest effect on rainfall distribution pattern. Rainfall intensity had a significant impact on stemflow rate. Rainfall duration had a significant impact on throughfall rate and canopy interception rate. Pre-rain drying period had no significant impact on the three components of rainfall distribution pattern. Results of multiple linear regression analysis showed that the response of the three components of rainfall partitioning to rainfall characteristics was not synchronized, with stemflow being less affected by rainfall characteristics than throughfall and canopy interception.

Key words: least cost path, ecological corridor., pinch point, circuit theory, functional connectivity