Background Canopy interception method at present is still in short, though simulated rainfall fixed some problems on precipitation, the research on canopy interception of tall shrubs and even arboreal forests is still limited. Beijing is located in a sub-humid and sub-arid continental monsoon climate area. This work is to study the redistribution of rainfall by the canopy.

Methods A simulated canopy rainfall interception experiment was conducted under the condition of artificial rainfall with QY JY-503C. and the results from the canopy interception simulated experiment was compared with that of field data in Robinia pseudoacacia, Platycladus orientalis, and Pinus tabulaeformis sample plots under the condition of natural rainfall. Field data of natural rainfall was collected in July to September 2018 of 3 sample plots.

Results 1) In the study period, canopy interception of R. pseudoacacia, P. orientalis and P. tabulaeformis sample plots were orderly 68.45 mm, 78.21 mm and 90.15 mm. They respectively accounted for 26.08%、29.79% and 34.34%t of the rainfall outside the forest. 2) Compared with canopy interception rates of three tree species simulated canopy with similar leaf area index, the canopy interception rates of R. pseudoacacia, Ps. orientali and P. tabulaeformis under the condition of natural rainfall were 4.57%, 2.7% and 0.63% respectively. This simulated experiment was better for canopy simulation of P. orientalis and P. tabulaeformis. 3) With the increase of leaf area index, the penetrating rainfall, throughfall ratio and stemflow rate of the same tree species under the same rainfall condition showed a decreasing trend. However, the canopy interception rate showed an increasing trend. 4) The canopy interception test of canopy model that took leaf area index as the control variable reflected canopy interception characteristics under natural rainfall conditions.

Conclusions In the research period, the canopy interception abilities of three species are all in the middle and upper level among the different forests. This study may provide new research and test method for canopy interception research and a theoretical basis for forest eco-hydrological process and impact mechanism research.