日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 A (大気水圏科学) » A-HW 水文・陸水・地下水学・水環境

[A-HW23] 水循環・水環境

2019年5月29日(水) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:町田 功(産業技術総合研究所地質調査総合センター)、山崎 大(東京大学生産技術研究所)、林 武司(秋田大学教育文化学部)、福士 圭介(金沢大学環日本海域環境研究センター)

[AHW23-P09] Quantifying stemflow to better express its ecohydrological significance

*飯田 真一1Carlye-Moses Darryl E.2Germer Sonja3Llorens Pilar4Michalzik Beate5南光 一樹1Tischer Alexander5Levia Delphis F.6 (1.国立研究開発法人森林研究・整備機構森林総合研究所森林研究部門森林防災研究領域、2.Department of Geography and Environmental Studies, Thompson Rivers University, Kamloops, British Columbia, Canada、3.Department of Bioengineering, Leibniz Institute for Agricultural Engineering and Bioeconomy, Potsdam, Germany、4.Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain、5.Soil Science, Institute of Geography, Friedrich Schiller University Jena, Jena, Germany、6.Department of Geography and Department of Plant and Soil Sciences, University of Delaware, Newark, DE, USA)

キーワード:Stemflow、Funneling ratio、Forest hydrology

Stemflow is the flow of rainwater over the exterior of a tree stem to its base. Due to water balance calculations to obtain interception loss of forest stands, and the sometimes low percentage of stemflow as a function of rainfall, some literature ignores the ecohydrological significance of stemflow. However, stemflow is much more concentrated than throughfall per unit area. In recognition of the extreme amounts of water input to the small area around tree trunks, we advocate for two metrics to better express stemflow in relation to its ecohydrological importance: namely, the stand-scale funneling ratio and the stand-scale infiltration funneling ratio. We calculated these metrics based on measurements carried out in a tropical dry deciduous forest and a subpolar juvenile coniferous stand, and found that these are significantly larger than throughfall on both sites. The data cited from recent papers (n=34) showed that very small stand-scale amount of stemflow (approximately 0.5% on average) were necessary to make the stand-scale funneling ratio to be equal or more than unity. Moreover, the infiltration area of stemflow is generally < 0.2 m2 due to the high infiltration capacity of top soil of forests, generally resulting in the stand-scale infiltration funneling ratio substantially greater than unity. Thus, stemflow is more effective for soil water recharge than throughfall. We recommend use of these metrics to better express ecohydrological importance of stemflow.

This presentation is based on the published paper as follows:
Carlye-Moses, D.E., Iida, S., Germer, S., Llorens, P., Michalzik, B., Nanko, K., Tischer, A., Levia, D.F. (2018): Expressing stemflow commensurate with its ecohydrological importance. Advances in Water Resources, 121, 472-479. Free open access article to: https://doi.org/10.1016/j.advwatres.2018.08.015