European floordplain forests represent specific biogeocoenoses with particular plant communities, development patterns, and anthropogenic effects. The present areas of floodplain forests show diverse characteristics in the valleys of mountains and in the piedmont parts of rivers. Dynamic changes take place there in therms both of the sites and the plant communities. More stable forest sites develop in a relatively narrow zone along the valley edge. Natural rivers alter their channel year by year, and their stony deposits become covered with initial vegetation in the majority of the valleys. Alluvial areas in the lowland parts of watercourses have existed for a very long time. In the gravel deposits of rivers, deposites of a sandy, loamy and clay character are left over time. This process has taken place since the beginning of Neolithic times (Opravil 1983; Stanova 1999). Frequently, from the Mesolithic era to the beginning of the Middle Ages, such areas became the location for human settlements. People abandoned these settlements after the 13th century when new sedimentations of loam occurred as a result of increased erosion in mountain areas (Polasek L. 1999). In the course of changes in the hydrological regime and in the sedimentation processes, transformations in the character of forest stands also occurred. Hard-wood floodplain forests changed into soft-wood floodplain forests, and back again into hard-wood floodplain forests. These changes have often been affected over the last two centuries by man's interventions. At present, floodplain forests occupy a relatively small surface compared with their original area. The largest ones have been preserved in Central and Eastern Europe, though even here their area has been reduced. The main anthropogenic effects on floodplain forests can be summarized as follows: - decrease of the floodplain forest area in favour of agriculture, often to the level of riparian stands; - watercourse regulation resulting in the termination of floods and a decrease in the groundwater table; - construction of dams (hydroelectric power stations) or water reservoirs resulting in the destruction of large floodplain forest areas (e.g. the Dnepr River in Ukraine, or the Nove Mlyny reservoirs, S. Moravia); - interactions between floodplain forests and housing settlements (particularly increased recreational use of floodplain forests, road construction, sports areas, etc.); - interactions between floodplain forests and intensively managed agricultural land in their immediate vicinity (increased input of various substances, particularly through wind erosion from fields to forests); exploitation of raw materials in fluvial plains and particularly in oxbow lakes after river regulation (sand and gravel exploitation); - intensive game management (high game populations, establishing game preserves); - fragmentations of floodplain forest ecosystems often below the limit of the minimum ecological range for a number of autochthonous plant communities and animal species, and thus also the formation of ecotones or even barriers disturbing the integrity of ecosystems. The current main features of floodplain forests include: - high production levels; - high biodiversity based on the high variability of forest sites; - the protection of watercourses against erosion and pollution; - a high number of nature reserves; - recreational and aesthetic functions within the landscape. At present, the main issues related to the positive development of floodplain forests are as follows: 1. Revitatlization projects, particularly removing the consequences of changes in the water regime; 2. Methods of regeneration and management of floodplain forests with the support of natural or semi-natural processes; 3. Protection/conservation of floodplain forests at various levels with the goal of protecting or increasing the biodiversity of floodplain forests; 4. To support the scientific activities of institutions involved in detailed studies at the level of ecosystems, including those in the area of catchment basins and related regions.
