Can Large Rivers Be Restored?

Abstract

Riverine ecosystems are remarkably resilient in their ability to recover from physical and chemical disturbances. If the disturbance occurs as a pulse, recover to the ecosystems`s original condition often occurs. However, if the disturbance is sustained and causes complete loss of critical habitat elements, ecological integrity cannot be maintained. Because running water ecosystems are so intimately tired to physical, chemical, and biological processes that occur throughout the catchment restoration is a complex and difficult task. Restoration and rehabilitation projects on small streams and rivers have been common practice for many years; however, restoration and rehabilitation projects for large river systems are far less common, and there is little ability to predict success or monitor recovery. Renewal of physical and biological interactions between the main channel, backwaters, and flood plains is central to rehabilitation. This article discusses the following topics in some detail: River channel manipulations; Backwater treatments; riparian zone and floodplain alterations; flow regulation; predicting recovery rates. 66 refs., 6 figs. 2 tabs.