Initial recruitment and re-germination mechanism of riparian vegetation onto bare sand bars

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06575
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Nagoya University
• Principal Investigator: Toda Yuji 名古屋大学, 工学研究科, 教授 (60301173)
• Co-Investigator(Kenkyū-buntansha): 椿 涼太 名古屋大学, 工学研究科, 准教授 (80432566) ; 尾花 まき子 名古屋大学, 工学研究科, 助教 (10447831)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 水工水理学 / 河川工学 / 河川植生 / 初期侵入・再萌芽

Outline of Final Research Achievements

This study aims to clarify the initial recruitment zone of riparian vegetation based on the field investigations. The results show that more seeds accumulated at the shoreline than that at the flat area of the bare bar. It was also found that the seed density at the downstream side of dunes on the bare bar is much higher than that at the upstream side. The hydrochory may be the dominant factor for seed dispersal to shoreline, and wind is the significant seed dispersal approach to the downstream side of dunes on bare bar. The initial recruitment model was proposed with the consideration of inundation frequency, sediment transport and spring flood. The simulation results showed that the initial recruitment zone is along the shoreline with the line shape. The comparison of simulation and field survey results show that the initial recruitment model can well predict the initial recruitment zone.

Free Research Field

河川工学

Academic Significance and Societal Importance of the Research Achievements

裸地砂州への植生の初期侵入・再萌芽について，これまでは現地観測の困難さから実測データが不足していたが，本研究の成果により実河川での定量的・実証的データが得られ，その知見に基づいて植生初期侵入の予測モデルが開発されており，データ，モデルともに新規性の高い学術的成果が得られた．河川の樹林化現象は国内外の河川で報告され，河川管理上の課題となっており，それに対して，樹林繁茂のきっかけとなる初期侵入機構を明らかにする本研究の成果は，今後の河川植生管理の効率化・高度化への発展が期待される有用性・発展性の高い成果と考えられる．