Abstract Although stemflow (SF) had been regarded as a small portion of the gross rainfall (GR), recent studies have revealed that, depending on the forest stand structure, the SF/GR ratio should not be neglected. This study derived SF/GR estimation models using common forest inventory data. A set of SF/GR ratio and forest inventory data (stand density (SD), total basal area (BA), mean diameter at breast height ( D B H ¯ ), mean tree height ( H ¯ ), canopy cover (CC), and leaf area index (LAI)) was collected from previous studies of Japanese cedar and cypress plantations. To further investigate the relation between SF/GR ratio and forest stand structures, we examined additional stand-structure variables (mean basal area ( B A ¯ ), mean stem surface area ( S A ¯ ), and total stem surface area (SA)) derived from the inventory data, and the stand-scale funneling ratio (FRstand) evaluating the efficiency of funneling rainwater. Among all the stand-structure variables, SD exclusively determined the SF/GR ratio, providing the best-fitting positive single linear regression equation as a density-based SF/GR model with a root mean square error (RMSE) of 2.4%. Although this model is useful for practical forest water management because it requires only SD which is the most basic forest inventory data, it has a weak point in meticulous forest water management because it cannot reflect the effect of tree growth on SF/GR ratio. Thus, we developed a size-based SF/GR model (RMSE = 2.0%) based on the strong relationship between the FRstand and D B H ¯ . This model is applicable to meticulous forest water management because it reflects the effects of not only SD but also tree growth by DBH on SF/GR ratio. These models derived from the common forest inventory data are potentially applicable to the evaluation and control of SF in forest water management.

中文翻译：

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使用常见森林清单数据的日本雪松和柏树人工林的茎流估计模型

摘要 尽管茎流（SF）被认为是总降雨量（GR）的一小部分，但最近的研究表明，根据林分结构，不应忽视 SF/GR 比。本研究使用常见的森林清单数据推导出 SF/GR 估计模型。一组 SF/GR 比率和森林资源清查数据（林分密度 (SD)、总基面积 (BA)、胸高平均直径 (DBH¯)、平均树高 (H¯)、冠层盖度 (CC) 和叶面积指数 (LAI)) 是从先前对日本雪松和柏树种植园的研究中收集的。为了进一步研究 SF/GR 比率与林分结构之间的关系，我们检查了额外的林分结构变量（平均基面积 (BA¯)、平均茎表面积 (SA¯) 和总茎表面积 (SA)）推导从库存数据来看，以及评估漏斗雨水效率的林分漏斗比（FRstand）。在所有林分结构变量中，SD 专门确定 SF/GR 比率，提供最拟合的正单线性回归方程作为基于密度的 SF/GR 模型，均方根误差 (RMSE) 为 2.4%。该模型虽然只需要最基础的森林清查数据SD，对实际的森林水管理很有用，但在细致的森林水管理中存在不足，无法反映树木生长对SF/GR比的影响。因此，我们基于 FRstand 和 DBH 之间的强关系开发了一个基于尺寸的 SF/GR 模型（RMSE = 2.0%）。该模型适用于精细的森林水资源管理，因为它不仅反映了 SD 还反映了 DBH 对 SF/GR 比的树木生长的影响。这些源自公共森林清单数据的模型可能适用于森林水资源管理中 SF 的评估和控制。