The Ecosystems of the Danube Delta Biosphere Reserve state-of the-art

Abstract

Taking into account the morphologic-hydrographic configuration of natural ecosystems or ecosystems partly modified by man the area, its flora and fauna communities and the long-term human impact, the two main categories of Danube Delta ecosystems associated with Razim-Sinoie lake complex, coastal marine waters and the Danube flood plain between Isaccea and Tulcea, as part of Danube Delta Biosphere Reserve, have been delimited: natural ecosystems or ecosystems partly modified by man; anthropic ecosystems. To identify and characterize ecosystems, there have been analysed the data on hydrography, morphology, biodiversity, human settlements, types of land use, spatial changes through the construction of agricultural, fisheries, forestry polders, modification of the network of channels and canals with consequences on the water circulation system inside the delta. The first category, of natural and partly modified by man ecosystems comprises 23 types (water bodies: running waters-Danube and its main branches, channels and canals; standing freshwater-lakes; standing brackish and salt waters-coastal lagoons, coastal, marine zones; wetlands: water fringe vegetation-flooded reed beds, floating reed beds , riparian willow formations, frequently flooded river levees; forests, shrubs and herbaceous vegetation: temperate riverine forests-mixed oak woods, shrubs and herbaceous vegetation, steppe meadows, meadows on low marine levees; dunes, beaches).The second category, of anthropic ecosystems includes 7 types (agricultural lands, forest areas-plantation on the river banks, fish farms, settlements-villages, towns). With the establishment of the Danube Delta Biosphere Reserve in 1990, with the statutory provisions on the protection and conservation of biodiversity, the deltaic landscape, some of the previous pressures were reduced, but the pollution of the Danube waters less consolidated beaches (Sulina, Sfântu Gheorghe, Chituc) and related with touristic activities, on ecosystems as a whole. The tourism activities also must represent not only a positive and dynamic development factor but also a practical solution to keeping the environment unaltered. These aspects were mentioned in the characterization of the ecosystems presented in this article.