The Impact of Floods on the Structure and Functional Processes of Floodplain Ecosystems

Floodplains are among the most endangered ecosystems in the modern landscape. Due to changes in land-use and river regulations, about 10 % of their global original area has left. The increasing magnitude and frequency of river flash floods caused by global climatic changes represent a further and significant disturbance factor that affects the remaining riverine ecosystems. However, floodplains play important beneficial socio-economic and ecological functions in the landscape and they deserve protection and restoration. This contribution provides a short review of our knowledge about river floodplains, their distribution, and structure and ecosystem services. Special attention is given to the negative impacts of river regulation on the biodiversity, structure and functions of river floodplain ecosystems. The effects of inundation stress and flood disturbances on riverine floodplains at various structural and functional ecosystem levels, such as vegetation, plant metapopulations and plant physiology and properties of floodplain sediments, their pollution loads and soil microbial activities are also shortly summarized. The contamination of floodplain sediments by conventional and modern types of pollutants represents a serious threat not only for edaphon and animal compartment of riverside ecosystems but also for sustainable utilisation of the floodplains by local riverine human populations. A better understanding of floodplains in the context of current environmental conditions can be utilised to develop new protection and rescue programmes to enhance the ecological stability of landscapes and mitigate and adapt to the effects of climate change.