Process-oriented ecological analysis of a dynamic riparian ecosystem: the lower river Allier (France)

Riparian ecosystems are highly dynamic ecosystems subjected to hydrogeomorphological processes. Their geomorphological, sedimentological and hydrological heterogeneity makes them one of the richest ecosystems in terms of species diversity. In addition, riparian zones also provide numerous ecosystem functions and services to society. In the European context, the lower river Allier (France) is one of the last remaining rivers with laterally dynamic sections. Its historical evaluation has shown repeated river bed displacements during the last century. Spatio-temporal processes on a highly mobile river section of the lower river Allier have been studied analysing the mosaic of vegetation types and successional phases as well as physical habitat parameters. Understanding riparian ecosystem functioning and evolution in natural or nearly natural systems is essential for river restoration practices in highly degraded rivers. This understanding may lead to the establishment of better sustainable river rehabilitation targets that consider societal needs and natural processes.