应用热脉冲方法对红富士苹果树干茎流速率的研究

采用热脉冲探针和数据采集器,测定了黄土高原地区苹果园红富士树干的液流速率.结果表明,单棵树的边材径向液流速度的总趋势是从形成层向内逐渐减少,边材12 mm处的液流速率占5 mm处液流速率的0.6～0.7,而32 mm处的速率仅为5 mm处的0.2左右.苹果园红富士树干的液流速率变化在晴天表现为单峰曲线,在生长季4～8月期间晴天,树干茎流在早晨6:30～7:00 时开始启动,形成层下5 mm处树干液流速率在4～5 cm/h以上,在12:30～14:30 时达到最大值,期间树干液流速率基本保持在45～57 cm/h以上,最大值可达到64.6 cm/h.在22:00时树干液流速率降低到最低水平,并维持到第二天液流启动时,这段时间树干内几乎没有树液流动.在阴天表现为较低水平的多峰曲线.

Research on Sap Flow Velocity of Red Fuji Apple Trees by Heat Pulse Probe Method

Heat pulse probe HPV4 and CR1000 data logger was used to monitor sap flow velocity of Red Fuji of orchards grown in the Loess Plateau.The results showed that the trend of the sap flow velocity along the radius below the cambium in sapwood is decreasing to the heartwood as a single tree.The velocity of the position 12 mm under the cambium is 0.6 to 0.7 of velocity at 5 mm,while the velocity at 32 mm is only 0.2 of velocity at 5 mm.The trunk sap flow velocity behaves a single peak curve in sunny days,the sap flow velocity begins ascending at 6:30~7:00 from April to August, the velocity can be more than 4 to 5 cm/h and reaches peak at 12:30~14:30.In this period,the velocity keep more than 45 to 57 cm/h,maximum is 64.6 cm/h.the velocity get the lowest at 22:00 and keep it to the next morning.In this period,there is almost no big sap flow,the trunk sap flow velocity behaves a more-peak curve in the cloudy day,and the peak in velocity are low.