Monitoring floodplain restoration.

River corridors are naturally dynamic and ecologically complex components of a watershed and often contain a disproportionately high amount of the total regional biodiversity (Naiman et al. 1993; Ward et al. 2001). Unaltered river corridors have heterogeneous landscape features, dominated by dynamic conditions, and exhibit scale-dependent biophysical patterns and processes (Ward et al. 2001). A prominent feature within river corridors is the floodplain (Figure 1). Geomorphologists traditionally define a floodplain as a flat, depositional feature of the river valley adjoining the river channel, formed under the present climate and hydrologic regime and during times of high discharge (Leopold et al. 1964; Dunne and Leopold 1978; Leopold 1994). Hydrologists and engineers view the floodplain either as land subject to periodic flooding or the area flooded by the 100-year flood event (Dunne and Leopold 1978). Ecologists have defined the floodplain and accompanying habitats as areas that are periodically inundated by the lateral overflow of river or lakes, or direct precipitation or groundwater; the resulting physiochemical environment causes the biota to respond by morphological, anatomical, physiological, phonological, or ethnological adaptations, and produce community structures (Junk et al. 1989).