Contribution of lianas to community-level canopy transpiration in a warm-temperate forest

1. Lianas (woody climbers) have a greater amount of leaves relative to basal area or standing biomass than trees, and very wide vessels that permit efficient water transport. These features suggest that lianas possibly consume proportionally more water through transpiration than trees. Despite their potential importance, researchers have made only limited attempts to evaluate effects of lianas on forest water dynamics. 2. We conducted sap flow measurements for 1 year using a thermal-dissipation method for four
species each of lianas and trees in a liana-rich, warm-temperate forest in Japan and estimated the contribution of lianas to stand canopy transpiration. 3. Based on a calibration measuring water uptake rates from cut-stem ends, the actual sap flux (Fd) in liana stems was several times greater than those estimated from the original calibration provided for the method. In the field, lianas showed an average of 2–4 times greater Fd than trees throughout the year. Except for this dif...

1. 藤本植物（Lianas, woody climbers）相较于乔木，其单位基面积或单位现存生物量对应的叶量更高，且拥有宽大的导管以实现高效水分运输。上述特征表明，藤本植物通过蒸腾作用消耗的水分比例可能高于乔木。尽管藤本植物的生态重要性不容忽视，但目前学界对其影响森林水分动态的相关研究仍较为有限。
2. 本研究于日本一处藤本植物富集的暖温带森林中开展了为期1年的液流监测实验：针对4种藤本与4种乔木，采用热扩散法（thermal-dissipation method）进行测定，并估算了藤本植物对林分冠层蒸腾的贡献量。
3. 基于对切取茎段末端吸水速率的校准结果，藤本茎干的实际液流通量（Fd）较该方法原校准公式估算值高出数倍。野外监测结果显示，全年藤本植物的平均Fd均为乔木的2~4倍。除这一差异之外……