Hydrological and geomorphological impacts on riparian plant communities

Riparian vegetation is affected by both flood processes and the characteristics of landforms that are shaped by floods. In many instances, species occurrence can be linked directly to specific fluvial landforms. These spatial relationships are largely due to the role of floods in the differential destruction of vegetation, in the determination of substrate characteristics, and in the transport of propagules. Major floods may, depending on the climatic context, allow for the establishment of stands of vegetation, or restart processes of plant community change. Disturbance by floods can also affect biodiversity: species richness in some watersheds is greatest where steep valley floor gradients allow for high-energy floods. The recognition and analysis of hydrogeomorphological influences on riparian vegetation are complicated by multiple scales of environmental interactions, by the covariance of some environmental variables, and by feedbacks between vegetation and flood regimes.