Conservation of biodiversity in alluvial hardwood forests of the temperate zone. The example of the Rhine valley

Abstract

Destruction of wetland temperate forests was particularly high during the past three decades throughout the world. Among the alluvial communities, the hardwood forest, which represents the highest level of organization in big river plains, is very vulnerable to environmental damage. The present hardwood forests are scarce in Europe after wide clearcuts, and have suffered great damage after elimination of the natural river dynamics. In Europe, the Rhine is probably the most damaged fluvial system. However, hardwood forests are still present along the river, even if mainly seminatural and unflooded. The purpose of this paper is to present an overview of the ecological features of the Rhine hardwoods before and after human alteration, and to propose a planning strategy for their conservation, following the island biogeography theory of Harris. The ideas developed here could be used for other damaged river forests in the temperate zone.