A Study on the Stem Sap Flow of Acacia mangium

ICT-2000TE system was used to investigate the stem sap flow of Acacia mangium, an important species for afforestation in south China, in 2003. The characteristics of stem sap flow change, the daily change of sap flow amount, the sap flow in different points and yearly fluctuation were analyzed. The results showed that the daily sap flow amount followed a monopeak curve. The amounts of daily total sap flow in rainy season and dry season were 10.988×103 g and 5.082×103 g respectively and the yearly total was 2 238.265×103 g. There esisted significant differences among different positions of A. mangium in water transferring capacity. The position with the fastest sap flow located at the xylem of 15 mm. The daily accumulated sap flow amounts of sapwood in rainy season and dry season were 85.203×103 g·m-2 and 57.463×103 g·m-2 respectively. The entire process of daily sap flow presented a S-shape curve.