Fully developed, very tall, multi-layered, highly diverse riparian forests of oaks, ashes, elms, limes, maples, alders, poplars, cherries, apple, willows of the middle and lower courses of large medio-European river systems, in particular, the Rhine, the Danube, the Emst, the Elbe, the Saale, the Weser, the Oder, the Loire, the Rhone-Saone systems. Their highly complex structure is formed of eight strata to which participate up to 50 species of trees and shrubs. The upper arborescent stratum includes Quercus robur, Fraxinus excelsior, Ulmus minor, Ulmus laevis, Ulmus glabra, Populus alba, Populus tremula, Populus canescens, Populus nigra, Acer pseudoplatanus, Acer platanoides, Salix alba, Alnus glutinosa, Prunus avium, the lower arborescent stratum Malus sylvestris, Tilia cordata, the sub-arborescent shrub layer Alnus incana, Prunus padus and Crataegus monogyna. There are very varied high and low shrub layers and numerous lianas, Clematis vitalba, Tamus communis, Humulus lupulus, Hedera helix and Vitis vinifera ssp. sylvestris. Most diverse, structurally, floristically and faunistically, of all European ecosystems, and closest in that respect to tropical communities and to the warm temperate forests of the Pleistocene, the great fluvial forests of Europe are reduced to a few highly vulnerable examples, located mainly within the Rhine, Danube and Elbe systems.