Climate change and biodiversity in Europe's lakes
Eutrophication, whereby excessive nutrients in bodies of water cause dense plant growth and death of animal life from lack of oxygen, together with climate change could cause freshwater biodiversity to further decrease. The result could be a major shift in ecosystem metabolism, resulting in greater greenhouse gas emissions. The aim of the CLIMBING (Climate and nutrient impacts on lake biodiversity and ecosystem functioning) project was to investigate how a changing climate interacts with nutrient supply, thereby altering the relationship between biodiversity and ecosystem functioning in lakes. CLIMBING provided evidence of the negative effects of the combination of increased temperature and nutrient and hydrological changes on the food web and biodiversity of aquatic ecosystems. Results also show that lakes in warmer regions, like the Mediterranean, are particularly vulnerable to species extinctions. This is because the removal of one species could lead to the removal of an ecological trait, thereby resulting in changes to the functioning of the whole ecosystem. One of the project's findings is the need to mitigate the effects of climate change and to reduce the nutrient load entering lakes and other water bodies. Mitigation efforts should include more efficient application of fertiliser according to soil retention and crop needs, resulting in less intensive land use in catchments with sensitive freshwaters. Furthermore, establishing riverside vegetation will buffer against the transfer of nutrients to water bodies. Encouraging water channels to meander would increase the retention, decomposition and loss of organic matter and nutrients. Improvements to land management and agricultural practices would reduce the export of sediment, particulates and dissolved nutrients from catchments. Reduced nutrient loads from agriculture and industry can be achieved through proper sewage water treatment and control of air emissions loads. The project's findings are also likely to have an impact on the European Water Framework Directive Strategy and the EU Biodiversity Strategy to 2020. The initiative's outcomes will therefore play an important role in helping to conserve Europe's freshwater environment in the face of a changing climate.
Keywords
Climate change, biodiversity, lakes, freshwater, eutrophication, ecosystem
