Type: Link Language: English Author: Klement Tockner, Nicoletta Toniutti
What delivers biodiversity in riverine landscapes? Lessons from the Tagliamento Project Riverine landscapes are particularly distinct systems because of their open link to adjacent ecosystems, their interface position between land and water, and the constraints that hydrological and morphologic dynamics place on their flora and fauna. Most riparian ecosystems are also topographically unique systems occupying the lowest position in the landscape, thereby integrating upstream catchment-scale processes. Braided rivers, once keystone ecosystems in the Alps, are among the most endangered systems world wide. The Fiume Tagliamteno in NE Italy, with its 60 km long braided corridor, is a unique system remaining in the Alps. It offers the rare opportunity to investigate natural processes at a scale that can be studied almost nowhere else in Europe. Along the Tagliamento, we can witness in situ dynamic processes such as the formation of islands and the avulsion of channels. Six years ago, EAWAG/ETH started an interdisciplinary research project along the Tagliamento. The main goal was to tackle a challenging topic in ecology: the development of principles for guiding the sustainable management of riparian ecosystems. The key question was: What delivers biodiversity and biocomplexity along dynamic river corridors? In my presentation, I will discuss lessons that we can draw from our observations along the Tagliamento. Specific emphasises will be (i) on the role of large wood in delivering biocomplexity, (ii) on the relative contribution of individual habitat types to corridor biodiversity, and (iii) on the complex linkages between aquatic and terrestrial communities. Finally, I will underpin the importance of the Tagliamento as a model and reference ecosystem for the Alps. Today, the Tagliamento is a highly threatened landscape. Its future conservation and sustainable management will therefore be a benchmark for the European Water Framework Directive (WFD) and for the Commission for the Protection of the Alps (CIPRA). It is clear that if we are not able to protect our last semi-natural rivers, the discussions on restoration projects remain relatively useless.
Keywords: research, deadwood