| Summary: | International audience Riverbanks are assuming a large number of important ecological functions: biodiversity support, resistance to invasion, ecological corridors, biomass production, water purification, temperature regulation, flood control, and recreation. Besides hard engineering, soil bioengineering techniques for riverbank protection are very old nature based solutions and have been used for centuries throughout the world. First thought of mimicking nature to fulfil the function of erosion control, soil bioengineering techniques are now also formed to assume some of the other important ecological functions of riverbanks. Using mostly concepts and tools from restoration and functional ecology (but also from engineering and hydraulic), we conducted a set of studies and experiments (in greenhouse and on real works) that aimed at characterising and maximising the contribution of riverbank bioengineering techniques to some of these ecological functions, including biodiversity support, resistance to invasion, resistance to drought and erosion control. We assessed the capability of several types of managed and mineral riverbank to support both common (terrestrial plants and beetles, macrobenthic communities) and endangered biodiversity (Myricaria germanica and Typha minima). Regarding resistance to invasion, we studied the potential of bioengineering techniques to resist to the pressure of an invasive rodent (Myocastor coypu), and to outcompete Japanese knotweeds. Summer drought should increase with climate change, and is a major threat for bioengineering success; we then studied the resistance of Salicaceae and Tamaricaceae populations to harsh drought. Finally we worked to maximize erosion control function of these techniques by implementing bioengineering works in steep slope rivers (5-10%), and by assessing past shear stress resistance to flood. Our results show that soil bioengineering techniques can be definitely thought as a nature based solution for assuming both erosion control and main ecological ...
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