Wood density assessment to improve understanding of large wood buoyancy in rivers

摘要

Drift wood (or in-stream large wood, LW) plays an important role in river ecosystems by influencing hydrology, hydraulics, sedimentology, and morphology (Montgomery, 2003). An extensive literature now exists describing the influence of wood on stream ecology (Gregory et al., 2003), and more recently on stream geomorphology (Gurnell, 2012). Recent research has focused on the mobilization of woody material during floods (Comiti et al., 2012), as transported woody material can cause a substantial increase in the destructive power of floods （Ruiz-Villanueva et al.，2012）. The first works by Braudrick and Grant (2000) provided the basic framework to approach wood mobility. Following this, other studies were carried out to explore wood dynamics (Haga, 2002), monitoring and calculate wood budget (MacVicar and Piegay, 2012) and numerical modeling (Ruiz-Villanueva et al., 2013).