IRBAS | Analysis and synthesis of intermittent river biodiversity

With climate change and the increasing water needs of human populations, many rivers, rich in biodiversity, are becoming intermittent. What is the influence of this phenomenon on the communities of animal and plant species living in these environments? The FRB-CESAB IRBAS team undertook to collect and analyze the relevant data to answer this question. Across the globe a large number of rivers periodically stop flowing. These rivers are called intermittent rivers. They are found in most terrestrial biomes, not only in arid zones, where they are relatively common. Studies show that over the next century, their numbers and size will increase in regions affected by droughts, notably caused by climate change. Intermittent rivers, however, have been little studied. Aquatic and terrestrial ecologists have long considered that they do not fall within their scope. It has also been assumed for some time that intermittent rivers harbored only a small amount of biodiversity and were inhabited only by poor communities of drought-resistant species. In recent years, ecological studies of intermittent rivers have developed, in part because of the severity of drying in areas where water requirements are being felt. Many countries now have data and metadata available on these intermittent rivers. 

While these studies have led to the recognition that intermittent rivers need to be protected for their biological values, current management practices, intermittent river protection policies and legislation are often inadequate or non-existent. Effective management of intermittent river systems requires knowledge of the relationships between river flow components (e.g. drought periods, floods, base flow) and ecological responses.

This document summarizes, in just a few pages, the project’s context and objectives, the methods and approaches used, the main findings, and the implications for science, society, and both public and private decision-making.