热技术方法测算树木茎流的发展及应用

热技术方法根据其设计原理可分为热脉冲法、热平衡法、热扩散法和激光热脉冲法.回顾利用热技术方法测算树木茎流的历史,概述热技术方法的产生和发展过程,重点论述4种热技术方法的设计原理、最新研究成果和概况,及实际应用中需注意的问题.基于热技术法的特殊优点,对其拓展性应用前景进行了展望:应用热技术方法对林木耗水进行尺度扩展,扩展模型中主导环境因子的导入,不同树种群体耗水量的估测等难点问题的深入研究和解决,将推动热技术理论和研究方法的进步.对现有的研究成果和研究目标进行分析认为,热扩散方法将成为未来几年研究树木液流的重要测算方法.

Development and Application of Thermal Methods in Measuring Stem Sap Flow

This paper, dealing with the development and prospect of the thermal methods which can be divided into three ways (Heat Pulse Velocity, Heat Balance Method and Thermal Dissipation Method), advances the problems in practical applications and emphasizes on the principles and research instances up to date by reviewing the history of using it in sap flow calculation. The in_depth investigations and appropriate solutions of some intractable problems, such as extrapolating the stand water consumption from whole tree water use measured by thermal technique, considering the dominant environment factors in scale_up model and determining the transpiration of a heterogeneous canopy, will promote the thermal methods in theory and in practice. Analyzing the actual research progress and targets, we can make a conclusion that Thermal Dissipation Method will be the vital techniques on stem sap flow measurement and calculation in the future.