Conservation planning for riverine biodiversity under changing climate: use of models

Floodplain habitat area and quality have decreased significantly over the last decades, mainly due to anthropogenic changes. Conservation efforts targeting floodplain species must consider changing climate when choosing suitable areas for restoration, especially for sessile organisms. Species distribution models, based on data from national and international databases on species’ occurrences and various environmental predictors, allow forecasting changes in species’ spatial distributions and facilitate planning at the catchment scale. Modelled predictions for floodplain organisms and communities suggest that current protected floodplains in Switzerland do not provide sufficient habitat and refugia for typical floodplain species and that climate-adapted conservation planning is needed which includes new areas. Similarly, visualisations of habitat which might potentially be occupied in the future can help to distinguish refugia from short-term sanctuaries. Temporal changes in water availability, for example, during periods of droughts, are likely to further lead to local habitat decrease of floodplain plant communities, as can be shown in hydrological models at reach scale for the Rhine in Germany. In fragmented landscapes along rivers, protected areas can provide refuge for specialised terrestrial species and promote species conservation, as we report for a floodplain which was protected for 30 years. Future restoration projects at the reach scale should, therefore, include planning at the catchment level, as well as consider hydrological regimes at the reach scale, especially for sessile floodplain species’ conservation under changing climate. Highlights Floodplain communities are threatened, especially sessile species; Climate-driven species distribution models distinguish refugia and sanctuaries; Hydrological predictions under changing climate show shifts of habitat for riverine plants at the local scale; A case study from a protected area shows that it promotes floodplain biodiversity; Prioritisation of local restoration projects should be based on planning at the catchment scale.