Ecosystems associated with rivers are intricately connected to their entire watershed. The river ecosystem includes the channel of active water flow, floodplain, and riparian and hyporheic zones. This ecosystem is shaped by interactions among the natural flow of water, sediments within the river and entering the river, and large wood regimes within the riparian zone. River integrity describes the ability of a river ecosystem to adjust to changes in these elements and through these adjustments maintain the habitat, disturbance regime, and connectivity necessary to sustain native biotic communities. Riverine food webs conceptualize the coupling between the physical environment and biotic communities and can be used to examine recovery from disturbance, variation in the structure of communities, and sources of energy that fuel metabolism within the ecosystem.