Determination of the vegetation effect on epikarst water recharges on permeable bedrock is important for the effective management of groundwater resources in forested area. However, little information is available on the effect of fine-scale throughfall and stemflow on epikarst water sources in karst regions. In this study, the oxygen (δ¹⁸O) and hydrogen (δD) isotopic compositions of throughfall, stemflow, and borehole water in forested area (TO) and shrubed area (CA) were determined. In this study, the mean daily volume of throughfall (45.89 ± 26.22 mm) was far higher than that of stemflow (0.74 ± 0.51 mm). Using a mass-balance equation, throughfall contribution to groundwater recharge and stemflow contribution to groundwater recharge in TO sample plot were 49 and 51%, respectively. While in CA sample plot, throughfall contribution to groundwater and stemflow contribution to groundwater was 43.7 and 56.3%, respectively. Compared with throughfall, stemflow was only a small part of the storm input; however, it composed of the similar recharge proportion to epikarst water. Stemflow drainage from trees rapidly concentrates large volumes of water by preferential flow which bypass root–rock interface, while throughfall produced scattered point-source inputs to epikarst zone by piston flow. Throughfall and stemflow recharge to epikarst zone in vegetation area was not statistically correlated with rainfall, throughfall volumes, stemflow volumes, and groundwater depth, which was related with the structure and conduit connectivity of karst water-bearing medium. The results provided useful suggestions on groundwater exploitation and utilization in karst areas.

确定植被对可渗透基岩表层水补给的影响对于有效管理林区地下水资源很重要。然而，关于细尺度贯通和茎流对岩溶地区表层岩溶水源的影响的信息很少。在本研究中，氧气 (δ ¹⁸确定了林区 (TO) 和灌木区 (CA) 的直通落水、茎流和钻孔水中的 O) 和氢 (δD) 同位素组成。在这项研究中，平均每日流量 (45.89 ± 26.22 mm) 远高于茎流 (0.74 ± 0.51 mm)。使用质量平衡方程，在 TO 样地中，通过落水对地下水补给的贡献和茎流对地下水补给的贡献分别为 49% 和 51%。而在 CA 样地中，直通流量对地下水的贡献和茎流对地下水的贡献分别为 43.7% 和 56.3%。与直通流量相比，茎流只是风暴输入的一小部分；然而，它由与表层岩溶水相似的补给比例组成。树木的茎流排水通过绕过根 - 岩界面的优先流快速集中大量水，而通过活塞流产生分散的点源输入到表层岩溶区。植被区表层岩溶带的径流和茎流补给量与降雨量、径流量、茎流量和地下水深度无统计学相关性，与岩溶含水介质的结构和管道连通性有关。研究结果为岩溶地区地下水的开发利用提供了有益的建议。和地下水深度，这与岩溶含水介质的结构和管道连通性有关。研究结果为岩溶地区地下水的开发利用提供了有益的建议。和地下水深度，这与岩溶含水介质的结构和管道连通性有关。研究结果为岩溶地区地下水的开发利用提供了有益的建议。