Geomorphic dynamics of floodplains: ecological implications and a potential modelling strategy

1. The dynamics of channel migration and floodplain renewal constitute an important control of the ecological diversity of river corridors. Restoration initiatives should therefore assess whether these dynamics must be reinstated in order to address the cause rather than the symptoms of floodplain biodiversity decline. 2. Restoration of reach-scale dynamism in rivers where this is a natural behavioural process will restore smaller-scale geomorphological and sedimentological processes that encourage vegetation regeneration, but may require catchment-scale management of material flows. 3. Channel dynamics depend on the style of river-floodplain interaction, and this may be summarised in qualitative, classificatory, sedimentological models of floodplain architecture that have been somewhat neglected in the ecological literature. 4. One approach to the assessment of floodplain biodiversity and its restoration would be through the development of simulation models based on specified channel styles, and involving simplified hydrodynamics and successional changes. Such models, currently the subject of research as a spin-off from modelling studies of landscape evolution, would permit evaluation of the consequences for ecological diversity of implementing various management options that may affect the dynamics of channel migration.