From the forest to the stream: the important role of instream wood in fluvial ecosystems
Dr. Virginian Ruiz-Villanueva, Institute for Environmental Sciences, University of Geneva
Tuesday 13 November 2018 (12h00 - 13h00) - Géopolis - 3899
Many decades ago, riparian vegetation was recognized as a primary control on fluvial ecosystems. It is well established now that fluvial processes cannot be understood without considering the biological influences. However, the recognition of instream wood as a key driver of fluvial processes did not start until recently and it is still very immature. This is partially explained because after centuries of forest, and river management, instream wood has been reduced significantly worldwide to facilitate navigation and control floods, resulting in rivers with minimal or no instream wood, and when present, it is often perceived in a very negative way. This presentation will shortly describe the key ecological functions of instream wood, and will show the main processes involved in the instream wood dynamics, drawing analogies with inorganic sediment. Moreover, the talk will show the most recent techniques to quantify wood in rivers, such as the use of unmanned aerial vehicles, monitoring using video cameras or numerical modelling. These techniques have been recently used within the context of the WoodFlow project in Switzerland (2015-2019, founded by the Federal Office for the Environment). The purpose of this project is to develop the knowledge and methods to analyse instream wood dynamics and to mitigate potential wood-related hazards in Swiss rivers. This contribution will present an overview of the project and some relevant results.