Natural conditions
The site is an almost 172 km long section of the Danube river demarcated with the left-sided tributaries Morava and Ipeľ. The site includes a rich network of river branches and adjacent wetland complexes. Especially in the upper part of the area – where the rapidly flowing river of montane character turns into huge and slowly flowing lowland river – is the branch system exceptionally rich developed, and it constitutes the so called Danube inland delta.Geological basement is formed by the gravel-sand deposits of several tenths meter of depth. In the area of the Danube inland delta (upper part of the site) the river has changed its course regularly, forming still new river branches and islands. Danube river was characterized by rapid rates of lateral erosion (maxima from 7,5 to 37 m annually), and extensive areas of point bars and gravel bars. Within three to seven years, new bars were stabilized by Salici-Populetum woodlands which subsequently developed into more stable vegetated islands. Human interventions were relatively common and frequent in the past, though increasing fluvial activity during the 18th century was responsible for their limited effectiveness. This large river activity created a unique mosaic mixture of various habitats.
The aquatic habitats in the area present large spectrum of different types; the main factors determining the ecological conditions are flow velocity, size, age, flood regime and possible drying up . The present aquatic vegetation can be classified as a mixture of lothic and lenitic habitats with a wide range of diverse ecological parameters.
The terrestric habitats are formed by flood regime, soil type, ground water level and anthropic management. On a relatively small territory there is present a mosaic of soft- and hardwood floodplain forests, fragments of Pannonian forest, dry forest-steppe (Danube forest-steppe – Asparago-Crataegetum) areas and secondary hay meadows. The present terrestric vegetation consists of residual alluvial forests with (Salicion albae, Alno-Padion), riparian mixed forests (withFraxinus angustifolia, Quercus robur, Ulmus laevis, U. minor), and small pieces of Pannonian oak woods. Secondarily lowland hay meadows were created, however presently the most of the long-used meadows were changed into arable land or afforested
Formerly large areas of the site were used for extensive grazing of cattle and horses. At moment majority of the former meadows are abandoned, changed into arable land or planted with hybrid poplars. Excessive logging, large scale clear cuts and plantations of non-native hybrid poplars caused, that only last fragments of the natural floodplain forests remained. Forest management was one of the most serious impacts which has lead to the large scale destruction and degradation of majority of natural Danube floodplain forests. Forest management practices have been focused only on maximal wood and pulp production, using large scale clear-cuts (up to 5 ha), removal of the top soil layer by using heavy bulldozers and planting of hybrid poplars and other non-native tree species. These forest management practices have been commonly used almost in whole Danube floodplain territory, continuously destroying natural forest habitats and threatening even the last remaining natural forests. Artificial plantations of hybrid poplars are being harvested in the age of 20-40 years, and this practice severely limits the chances for survival for species depending on the old trees and dead wood. This affects wide range of the plant and animal species, including species listed in the Annexes of Habitat and Bird Directives.
