How does spatiotemporal dynamics of large wood impact its ecosystem services in a meandering river?

Large wood is an essential component of the river channel. Channel morphodynamics are impacted, specific habitat for aquatic biota is created, and aesthetic or education function is enhanced by the presence of large wood in the river. The concept of ecosystem services can be applied to describe the functions of large wood. In the case of large wood, there can also be potential risks for human society connected with flooding or bank erosion. We inventoried large wood in 13 active meanders of the Odra (Oder) River, Czechia, and its potential ecosystem services. We surveyed large wood using aerial images (2012 and 2020) and field surveys (2016 and 2020). Based on previous literature research, we assessed each large wood piece separately and decided on the services (3 main categories and 13 subcategories) based on the functions by preselected indicators. Preliminary results show that the functions and provided services depend mainly on the residence time of large wood in the channel and its additional characteristics such as dimensions, type of large wood (e.g., whole tree with preserved crown, present/absent root wad) or its orientation against the flow. We provide a methodological approach of (i) possible assessment of large wood in the river reach to summarize its benefits and risks and (ii) to simplify the understanding of the presence of large wood and its promotion to river practitioners, city planners, and the broader public.