How to reach a Good ecological status in rivers? Large scale models allow to identify regional pressures in European countries (France, UK, Slovaquia, Estonia)
Comment atteindre le "bon état écologique" dans les rivières ? Des modèles large échelle permettent d'identifier les pressions régionales dans des pays européens (France, UK, Slovaquie, Estonie)
Résumé
For the implementation of the Water Framework Directive, the question is no longer what is the good ecological status?, but how to reach it? Managers need diagnostic methods and pressures/impacts models allowing to set priority actions. We present large scale models developed in the REBECCA project. PLS regressions were used to evaluate the relative impact of land cover (at the basin and riparian corridor scale) on invertebrate indices taken from national monitoring networks; data were stratified by hydro-ecoregions. Urbanisation appears always as a dominant pressure, while arable lands have generally a negative impact, less acute but extensive, and more variable according to regions. Forests in the river corridor have a strong positive effect. The hydro-ecoregion level seems more informative to identify regional pathologies of river ecosystems.