In the great flora resources of the Upper Danube Basin the half of its territory is covered in the forest ecosystems. The most important species are the English oak (Quercus robur), the white poplar (Populus alba), the black poplar (Populus nigra), the white willow (Salix alba) and the ash (Fraxinus angustifolia). These species make autochthonous communities of ecological worth, often called floodplain forests. The problem of very hard natural reforestation, omnipresent in this region, leads to the constant reduction in the autochthonous species of the total forest reserves which influences the biodiversity of the region. By changing the type of wood which carries the ecosystem, the whole chain of flora and fauna is changed, and they often become impoverished. The best example of this is the change of the common oak, the species which makes extremely complex and worthy biocenosis, for the cultures of various poplar clones, which are simple to grow, and profitable as well.
The typical bushy species of the Upper Danube Basin are the red dogwood (Cornus sanguinea) and the hawthorn (Crattaeegus sp.). The Pannonian black hawthorn (Crataegus nigra) is very important among them, and it usually appears in the community with the common oak.
Three species from the reserve can be found in the first volume of the red book of flora in Serbia – “Iščezli i krajnje ugroženi taksoni”: water-violet (Hottonia palustris), winter aconite (Eranthis hyemalis) and mare's-tail (Hippuris vulgaris); but it is probable that this list will be enlarged in the future. The important species from the orchard family are hudson (Orchis purpurea), lamarck (Orchis laxiflora) and Dactylorhiza incamata. Of the relict importance is also the sub Mediterranean flora element, the abortive iris (Iris spuria). Strbac locality is interesting because it is the only place where the snakelike buttercup (Ranunculus ophioglossifolius) can be found in Vojvodina, and there are also salty meadows – mineral springs with their vegetation which contain Puccinellia limosa, Camphorosma annua and Cirsium brachychepalum. Among the most beautiful inhabitants of the reserve are the numerous white (Nymphaea alba) and yellow water lilies (Nuphar luteum), which are, although of the great esthetic importance, the indices of the general mudding.
One of the main features of the Special nature reserve “Gornje Podunavlje” is the mixture of ecosystems – waters, swamps, meadows and forests – which altogether make one big mosaic of different vegetation forms. Also, on the territory of the Upper Danube Basin there is a very distinctive micro relief, because of which even the smallest differences in the elevation cause the development and survival of various species. In favour of this is the fact that the whole flora of this region is placed in a very small height range (80-88 m). Because of this every, even the smallest, change of the terrain morphology causes the succession of the existing flora, which is very obvious in regards to the anthropological influence. These changes, that may seem imperceptible, later influence the whole living world of the Upper Danube Basin and permanently change its original marshy character.
In the great flora resources of the Upper Danube Basin the half of its territory is covered in the forest ecosystems. The most important species are the English oak (Quercus robur), the white poplar (Populus alba), the black poplar (Populus nigra), the white willow (Salix alba) and the ash (Fraxinus angustifolia). These species make autochthonous communities of ecological worth, often called floodplain forests. The problem of very hard natural reforestation, omnipresent in this region, leads to the constant reduction in the autochthonous species of the total forest reserves which influences the biodiversity of the region. By changing the type of wood which carries the ecosystem, the whole chain of flora and fauna is changed, and they often become impoverished. The best example of this is the change of the common oak, the species which makes extremely complex and worthy biocenosis, for the cultures of various poplar clones, which are simple to grow, and profitable as well.
Three species from the reserve can be found in the first volume of the red book of flora in Serbia – “Iščezli i krajnje ugroženi taksoni”: water-violet (Hottonia palustris), winter aconite (Eranthis hyemalis) and mare's-tail (Hippuris vulgaris); but it is probable that this list will be enlarged in the future. The important species from the orchard family are hudson (Orchis purpurea), lamarck (Orchis laxiflora) and Dactylorhiza incamata. Of the relict importance is also the sub Mediterranean flora element, the abortive iris (Iris spuria). Strbac locality is interesting because it is the only place where the snakelike buttercup (Ranunculus ophioglossifolius) can be found in Vojvodina, and there are also salty meadows – mineral springs with their vegetation which contain Puccinellia limosa, Camphorosma annua and Cirsium brachychepalum. Among the most beautiful inhabitants of the reserve are the numerous white (Nymphaea alba) and yellow water lilies (Nuphar luteum), which are, although of the great esthetic importance, the indices of the general mudding.