Vegetation patterns of floodplain meadows along the climatic gradient at the Middle Elbe River

• Stretching over a broad climatic gradient, floodplain plants may serve as indicators for climate change effects.
• Only species composition of wet meadows changed along the Middle Elbe River.
• River corridor plants were evenly distributed along the gradient.
• River corridor plants appear relatively robust against direct climatic changes.
• Total assemblages of wet meadows might be relatively vulnerable to climate change.

Central European floodplain meadows are characterised by flooding mainly in winter/spring and dry conditions over the summer. They harbour many rare and endangered plant species. We studied the vegetation of floodplain meadows along the regional climatic gradient of the Middle Elbe River. This gradient exhibits rather continental conditions in the south-east and oceanic conditions in the north-west. We aimed at detecting the influence of climate on the vegetation of floodplain meadows along this gradient.Along the Middle Elbe River (Germany), we recorded the vegetation of wet and mesic meadows in 2010. The results revealed differences in species composition especially in wet meadows: vegetation plots of wet meadows clustered in the DCA ordination according to their geographic location from west to east. Sample scores of DCA-axes of both meadow types correlated with the long-term means of climatic factors such as precipitation or temperature. While species numbers did not differ between study sites, evenness of mesic meadows was higher in the western part of the gradient.Indicative species of the sites were mainly common meadow species. Species typical for floodplain meadows were relatively evenly distributed along the gradient. Therefore, we confirm that the distribution of typical floodplain species is largely determined by hydrologic and land use conditions rather than by climatic factors. Therefore, we assume that typical floodplain meadow species at the Elbe River are relatively robust against direct climatic changes, as long as these changes do not exceed the range of the climatic gradient today. Concerning the total assemblages of floodplain meadows, those of wet meadows might be more vulnerable to climate change than those of mesic meadows. However, indirectly occurring changes caused by climate change, i.e. water-level changes due to an altered discharge regime of the Elbe River caused by altered precipitation patterns in the catchment, will affect all floodplain species.