热脉冲技术测定树干液流研究进展

热脉冲技术是生态生理学和森林水文学研究树木耗水最为常用的技术之一,该技术具有在树木自然生长状态基本不变的情况下实时测量树干木质部上升液流速度及流量,可以简捷准确地确定树冠蒸腾耗水量,同时具有经济可行,测定准确的优点.综述了热脉冲技术的发展历程,对热脉冲方法测定树干液流理论研究、树干液流时空变异性与环境因子的关系研究以及单株耗水向林分水平的尺度转换研究等方面作了较为详细的总结,据此,对热脉冲技术的发展做了展望.

Heat Pulse Technique Applied to Measure Stem Sap Flow: Principle and Research Advance

Heat pulse technique is one of the most common techniques used in measurements of whole tree water consumption ecophysiology and forest hydrology.It can be used to measure the rising sap flow rate and volume in the xylem of tree stems under natural living condition of trees,and thereby can be used to determine the water consumption of tree canopy through transpiration.In this paper,the principle of heat pulse technique is reviewed;the historical development of this method and the technique for measuring stem sap flow is also described briefly.The application conditions,performances and problems in applications were discussed.Based on the mentioned above,the future trends in development of heat pulse technique researches were forecasted.Future developments will certainly bring even better methods,but natural flow variation should always be taken into account.There will still be reasons for using different measuring and evaluation techniques to match special demands.