Riparian Restoration in the Western United States: Oveview and Perspecive

Abstract

This historical and conceptual overview of riparian ecosystem restoration discusses how riparian ecosystems have been defined, describes the hydrologic, geomorphic, and biotic processes that create and maintain riparian ecosystems of the western USA, identifies the main types of anthropogenic disturbances occurring in these ecosystems, and provides an overview of restoration methods for each disturbance type. We suggest that riparian ecosystems consist of two zones; Zone I occupies the active floodplain and is frequently inundated and Zone II extends from the active floodplain to the valley wall. Successful restoration depends on understanding the physical and biological processes that influence natural riparian ecosystems and the types of disturbance that have degraded riparian areas. Thus we recommend adopting a process-based approach for riparian restoration. Disturbances to riparian ecosystems in the western USA result from streamflow modifications by dams, reservoirs, and diversions; stream channelization; direct modification of the riparian ecosystem; and watershed disturbances. Four topics should be addressed to advance the state of science for restoration of riparian ecosystems: (1) interdisciplinary approaches, (2) a unified framework, {3) a better understanding of fundamental riparian ecosystem processes, and (4) restoration potential more closely related to disturbance type. Three issues should be considered regarding the cause of the degraded environment: (1) the location of the causative disturbance with respect to the degraded riparian area, (2) whether the disturbance is ongoing or can be eliminated, and (3) whether or not recovery will occur naturally if the disturbance is removed. DECEMBER 1997 RestorationRi'storatioti Ecology DECEMBER 1997

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Restoring Riparian Ecosystems During the UN-Decade on Ecosystem Restoration: A Global Perspective

“…The threats on riparian systems can be natural or human-induced (Fig. 2) (Goodwin et al 1997;Bendix and Hupp, 2000;Nilsson and Berggren, 2000;Iwata et al 2003;Richardson et al 2007;Cornejo-Denman et al 2018). Riparian systems are impacted by natural disturbances once in 50 years due to landslides and floods (Richardson et al 2007).…”

“…The successful planning of restoration requires an understanding of hydrogeomorphic processes and biotic change, processes that create and maintain riparian ecosystems (Goodwin et al 1997). The past channel changes and details of activities that influence sedimentation and flow, such as deforestation and damming, should be studied for effective planning (Kondolf and Larson 1995;Stromberg 2001).…”

“…Riparian restoration has been conducted worldwide (Kauffman et al 1995;Rood et al 2003;Shafroth et al 2008;White and Stromberg 2011;Gumiero et al 2013;Gonzalez et al 2015). It started from the early 1970s with studies on riparian ecosystems and restoration practices increasing from time to time (Hawkins, 1994;Goodwin et al 1997;González et al, 2015). Till 1995, in fact, more than 400 studies had been published only on riparian restoration in the western USA (Goodwin et al 1997).…”

“…It started from the early 1970s with studies on riparian ecosystems and restoration practices increasing from time to time (Hawkins, 1994;Goodwin et al 1997;González et al, 2015). Till 1995, in fact, more than 400 studies had been published only on riparian restoration in the western USA (Goodwin et al 1997).…”