Integrative freshwater ecology and biodiversity conservation

Freshwater ecosystems provide goods and services of critical importance to human societies, yet they are among the most heavily altered ecosystems with an overproportional loss of biodiversity. Major threats to freshwater biodiversity include overexploitation, water pollution, fragmentation, destruction or degradation of habitat, and invasions by non-native species. Alterations of natural flow regimes by man-made dams, land-use changes, river impoundments, and water abstraction often have profound impacts on lotic communities. An understanding of the functional interactions and processes in freshwater ecosystems presents a major challenge for scientists, but is crucial for effective and sustainable restoration. Most conservation approaches to date have considered single species or single level strategies. In contrast, the concept of 'Integrative Freshwater Ecology and Biodiversity Conservation' (IFEBC) proposed herein addresses the interactions between abiotic and biotic factors on different levels of organization qualitatively and quantitatively. It consequently results in a more holistic understanding of biodiversity functioning and management. Core questions include modeling of the processes in aquatic key habitats and their functionality based on the identification and quantification of factors which control the spatial and temporal distribution of biodiversity and productivity in aquatic ecosystems. The context and importance of research into IFEBC is illustrated using case studies from three major areas of research: (i) aquatic habitat quality and restoration ecology, (ii) the genetic and evolutionary potential of aquatic species, and (iii) the detection of stress and toxic effects in aquatic ecosystems using biomarkers. In conclusion, our understanding of the functioning of aquatic ecosystems and conservation management can greatly benefit from the methodological combination of molecular and ecological tools.