Development, maintenance and role of riparian vegetation in the river landscape

1. Riparian structure and function were considered from a longitudinal pers pective in order to identify multiscale couplings with adjacent ecosystems and to identify research needs. 2. We characterized functional zones (with respect to vegetation developmen t in association with various biogeochemical processes) within geomorpholog ical settings using a delineation based upon erosional, transitional and de positional properties. 3. Vegetation dynamics within the riparian corridor are clearly influenced substantially by hydrological disturbance regimes. In turn, we suggest that vegetation productivity and diversity may widely influence riverine biogeo chemical processes, especially as related to the consequences of changing r edox conditions occurring from upstream to downstream. 4. However, surface and groundwater linkages are the predominant controls o f landscape connectivity within riparian systems. 5. The importance of riparian zones as sources and sinks of matter and ener gy was examined in context of structural and functional attributes, such as sequestering or cycling of nutrients in sediments, retention of water in v egetation, and retention, diffusion or dispersal of biota. 6. The consequences of interactions between different communities (e.g. ani mals and plants, micro-organisms and plants) on biogeochemical processes ar e notably in need of research, especially with respect to control of landsc ape features. Multiscale approaches, coupling regional and local factors in all three spatial dimensions, are needed in order to understand more synth etically and to model biogeochemical and community processes within the riv er-riparian-upland landscape of catchments.