Canopy interception in original Korean pine forest: measurement and dividual simulation in Xiaoxing'an Mountains, northeastern China.

The interception of precipitation by vegetation and subsequent evaporation during and after rain events are an important component of the hydrological budget of forest ecosystems, particularly for forests in ecologically and hydrologically sensitive regions such as the original Korean pine (Pinus koraiensis) forest. The evergreen Korean pine is the dominant canopy species in Xiaoxing'an Mountains, northeastern China. We investigated the rainfall redistribution effect and its variation in the original Korean pine forest in Liangshui Nature Reserve via 119 rainfall events. 1) The throughfall, stemflow and canopy interception in the original Korean pine forest were 636.04, 14.62 and 177.84 mm, respectively, which accounted for 76.77%, 1.76% and 21.47% of rainfall in the open field. 2) In the original Korean pine forest, the logarithmic relationships were found between throughfall rate, canopy interception rate and precipitation in the open field (P0.01), while it was a linear function between throughfall, canopy interception and precipitation (P0.01). 3) Stemflow was generated when the precipitation in the open field exceeded 0.5 mm, and with the increase of rainfall, the stemflow rate increased (P0.01). 4) The maximum coefficient of variation was observed in stemflow and the minimum one in throughfall in the hydrological processes. 5) Dividual simulation and regression of classification showed that the break points of the interception-rainfall fitting curve were at 2.3 and 9.8 mm. Compared with the overall regression model, the dividual simulation had higher precision and conformed better to the eco-hydrological processes of canopy interception.