Reflections on the history of research on large wood in rivers

Abstract

Dynamics and functions of large wood have become integral considerations in the science and management of river systems. Study of large wood in rivers took place as monitoring of fish response to wooden structures placed in rivers in the central United States in the early 20th century, but did not begin in earnest until the 1970s. Research has increased in intensity and thematic scope ever since. A wide range of factors has prompted these research efforts, including basic understanding of stream systems, protection and restoration of aquatic ecosystems, and environmental hazards in mountain environments. Research and management have adopted perspectives from ecology, geomorphology, and engineering, using observational, experimental, and modelling approaches. Important advances have been made where practical information needs converge with institutional and science leadership capacities to undertake multi‐pronged research programmes. Case studies include ecosystem research to inform regulations for forest management; storage and transport of large wood as a component in global carbon dynamics; and the role of wood transport in environmental hazards in mountain regions, including areas affected by severe landscape disturbances, such as volcanic eruptions. As the field of research has advanced, influences of large wood on river structures and processes have been merged with understanding of streamflow and sediment regimes, so river form and function are now viewed as involving the tripartite system of water, sediment, and wood. A growing community of researchers and river managers is extending understanding of large wood in rivers to climatic, forest, landform, and social contexts not previously investigated. © 2020 John Wiley & Sons, Ltd.

Comparison of length and dynamics of wood pieces in streams covered with coniferous and broadleaf forests mapped using orthophotos acquired by an unmanned aerial vehicle

“…This contributes to changes in the ecosystem, channel morphology, and sediment flux through logjam formation and the decay of wood pieces (e.g., Wallace and Benke 1984;Lisle 1995;Montgomery et al 1995;Gurnell et al 2001;Comiti et al 2006;Ruiz-Villanueva et al 2016). Hence, the river form and function are determined by the interaction between water, sediment, and wood (Nakamura et al 2017;Swanson et al 2021). Therefore, quantifying wood pieces is important for assessing their impacts on ecological, geomorphological, and fluvial conditions.…”

“…Many previous studies focusing on wood pieces in streams have unraveled the role of wood pieces in various spatiotemporal scales and environmental settings (e.g., Nakamura et al 2017;Swanson et al 2021), but most of these approaches required direct field measurements such as local monitoring (e.g., Manners et al 2007), the tracking of wood pieces (e.g., Ravazzolo et al 2015;Wyżga et al 2017), and field experiments on artificial wood pieces (e.g., Haga et al 2002). Taking into account the diversity of forests around channels (e.g., age, species, and density of trees), the monitoring and field survey of wood pieces is evidently an effective approach.…”

Comparison of length and dynamics of wood pieces in streams covered with coniferous and broadleaf forests mapped using orthophotos acquired by an unmanned aerial vehicle

“…Hence, the river form and function are determined by the interaction between water, sediment, and wood (Nakamura et al, 2017;Swanson et al, 2020). Therefore, quantifying wood pieces is important for assessing their impacts on ecological, geomorphological, and uvial conditions.…”

Comparison of Length and Transport of Entrapped Woody Debris in Coniferous and Broadleaf Forests Based on Mapping Using Ortho-Photographs Acquired by Uncrewed Aerial Vehicle

“…This contributes to changes in the ecosystem, the channel morphology, and the sediment ux through woody-debris preservation and decay (e.g., Wallace and Benke, 1984;Lisle, 1995;Montgomery et al, 1995;Gurnell et al, 2001;Comiti et al, 2006; Ruiz-Villanueva et al, 2016). Hence, the river form and function are determined by the interaction between water, sediment, and wood (Nakamura et al, 2017;Swanson et al, 2020). Quantifying woody debris is important for assessing its impacts on ecological, geomorphological, and uvial conditions.…”