Flooded forests: ecology, threats and restoration

This video examines the ecology, hydrology, and conservation status of temperate floodplain (alluvial and riparian) forests, with a case study from West Acre in Norfolk, UK. It contrasts global persistence of floodplain systems, such as those in the Amazon and Danube Delta, with their severe decline in Britain. The discussion focuses on groundwater-driven flooding in lowland chalk catchments, where aquifer saturation elevates the water table and inundates woodland for extended seasonal periods. The hydrological dynamics of low-energy chalk streams are highlighted, including prolonged floodplain water residence times. Key plant adaptations to anoxic, waterlogged soils are explored, including aerenchyma formation, lenticel development, vegetative propagation strategies, and nitrogen fixation. Species ecology is illustrated through willows Salix spp. (early successional colonisers) and alder Alnus glutinosa (late-successional, flood-tolerant dominants). The habitat’s biodiversity value is considered, including its role in supporting bryophytes, lichens, specialist bird assemblages, and large herbivores. The video also evaluates historical and contemporary drivers of habitat loss, including river engineering, agricultural intensification, groundwater abstraction, and eutrophication. Finally, the discussion outlines restoration strategies, including floodplain reconnection, hydrological re-naturalisation, and landscape-scale recovery initiatives.