A Study on the Dynamics of Sap Flow in Space and Time in Poplar Stems
- Received Date: 1993-03-17
- Available Online: 2012-12-04
Abstract: The dynamics of sap flow in space and time in stem was studied by heat pulse technique in 2- and 6-year-old poplar plantation (Populus deltoides Bartr. cv. "Lux" ex. I-69/55) in Yinan County,Shandong Province in 1991. The research has revealed that the sap flow occurred in the sapwood of the stem. The sap flow velocity of the same annual ring is similar, but it varied obviously along the diameter direction. The sap flow velocity of the outer ring is higher than that of inner ring in daytime. The sap flow changes with meteorological factors and forms a curve with a widen peak. The quantity of sap flow in stem per hour is 3~6 L/h in 2-year-old tree and 20~35 L/h in 6-year-old tree. The sap flow volume in the stem per day is 13.6~22.8 L/d in 2-year-old tree and 89.2~152.6 L/d in 6-year -old poplar.