Abstract:

Granier sap flow system is one of the most commonly used techniques for measurements of whole-tree water use in ecophysiological and forest hydrological studies. However, in the literature there is not one paper that exclusively reviews the Granier method. In this paper, we recapitulate the theoretical basis of the Granier sap flow system and review recent developments in calibration and modification of the sensor probes. Practical issues, such as the determination of the non-flow signal values, natural thermal gradient, wounding effect, reversed sap flow pattern and extrapolation of individual measurement of sap flux density to whole-tree sap flow, are discussed in detail. In the perspectives, new approaches are put forward to use the strong coupling between photosynthesis and transpiration or canopy conductance, via the measurement of ¹³C discrimination, to estimate whole-canopy carbon assimilation.

    Granier热消散探针法是目前研究树木生理生态和森林水文最常用的测定整树水分利用的方法之一。然而，已有的相关综述文献中，还没有专门介绍利用Granier热消散探针研究木质部液流的综述文章。本文重点介绍了Granier热消散探针测定系统的理论基础，对有关该探针的校准和改进的最新研究进展进行了综述，并还深入探讨了零液流信号值的确定、自然热梯度、损伤效应、液流的逆格型和将木质部液流密度外推至整树蒸腾耗水量等重要的实际问题。

Key words: Granier method, natural thermal gradient, sap flow, sap flux density, thermal dissipation probe, whole-tree water use, wounding effect