In Europe and North America, up to 90% of floodplains have become extensively regulated, occupied, and polluted, with important consequences in the floodplain ecosystem. For this reason, exploring the processes that drive ecosystem structure and functionality is of great relevance in the development of effective management plans. In the Middle Ebro floodplain, the lateral hydrological connectivity was found to be the key factor structuring the habitats and aquatic communities, while turbidity, salinity and nutrient status were secondary drivers. The objective of floodplains restoration in the Middle Ebro floodplain should thus consist in re-establishing a wide range of wetland types in accordance with the river- floodplain potential of sustainability. The present book aims to provide a solid background for river-floodplain restoration based in the response of aquatic communities to changes in hydrological connectivity, environmental factors and human pressure across the floodplain of a Mediterranean river. Therefore, this book is addressed to a wide audience ranging from researchers, to environmental managers, the water industry and the society in general.