Restoration ecology of riverine wetlands: A 5-year post-operation survey on the Rhône River, France

Bibliographical study of articles published in scientific journals over the last 10 years, and of books published over the last 20 years, reveals a clear increase in the number of publications dealing with ecological engineering, particularly on aquatic ecosystems, which today are becoming a major topic. The concept of ecological restoration must be clearly defined scientifically and include adequate pre- and post-restoration monitoring of various performance indicators, to allow for restoration, evaluation and increase its success. A restoration experiment was carried out in a former channel of the Rhône River according to a scientifically based decision framework. Long-term monitoring of aquatic vegetation (17 years of data) on two former channels (reference and restored ecosystem) clearly demonstrated human impacts on aquatic ecosystems. A channel exhibiting rapid terrestrialization and eutrophication processes after completion of a hydroelectric scheme construction was restored. In keeping with the hypothesis, the increase in groundwater supply led the restored ecosystem to return to a less advanced and self-sustainable successional stage, whereas vegetation monitoring in the reference channel did not show significant changes over this 17-year of period, supporting long-term studies to determine the effects of restoration on the biota.