On the continental scale, Europe appears to have abundant water resources. However, these resources are unevenly distributed, both between and within countries. Once population density is taken into account, the unbalanced distribution of water resources per inhabitant is striking. There is a great variety of freshwater ecosystems, rivers, lakes and wetlands in cold, temperate and warm regions being distributed in low to steep gradient catchments, providing quite a variety in ecosystem conditions and potential response to climate change. European freshwaters are under intense pressure from multiple use, pollution and habitat degradation. Freshwater integrity but also freshwater ecosystem services to society have been reduced significantly. Ecosystem structure and function including the biota are strongly affected, with several aquatic species disappearing from entire ecoregions. Climate change will also play a significant role. In Europe, the principal legal instrument to halt the deterioration of aquatic ecosystems is the Water Framework Directive, which aims at restoring aquatic ecosystems back to good status. Together with other legislative frameworks it should improve, restore and conserve freshwater biodiversity. Climate change, however, may increase pressures and counteract attempts to restore aquatic ecosystems. It adds additional threats and interacts in complex ways with other stressor types.
Results/Conclusions
There has been little progress in the integrated management of water resources. Important changes in water management are expected in the coming years, following full implementation of recent directives. The future status of European freshwater ecosystems is dependent on changes in land-use, pollution loading and water demand, target-oriented conservation strategies, but also on the effects of climate change. Understanding how freshwater ecosystems will respond to future climate change is essential for the development of policies and implementation strategies needed to protect aquatic and riparian ecosystems. The important role of freshwater systems for conservation of biodiversity is largely recognised. For advancements in conservation, interactions and webs between freshwater and terrestrial habitats have to be considered. These aspects are currently the focus of the “Alpine Ecological Network”, where three closely linked initiatives are working together in implementing an effective ecological network for the Alps (www.alpine-ecological-network.org, www.econnectproject.eu). We consider riverine landscapes (rivers, riparian and catchments) especially in mountain areas as key units for ecological connectivity. We provide strong evidence that river-floodplain corridors are keystone ecosystems for maintaining local and regional diversity and ecosystem processes including connecting areas of high biodiversity values with densely populated low altitude areas.