Bodies of Water
Streams and Riparian Areas
The water bodies and especially the streams form the core and connecting element of the characteristic habitat in the Elbe Valley. The Elbe stream in particular has a high structural diversity:
- riverbed with sand and mud banks due to erosion and sedimentation processes,
- structure-rich riparian zones including groyne fields with extensive alternating gravel, sand and mud areas,
- floodplain with flood channels and oxbow lakes.
The Elbe is a nutrient-rich watercourse with a high suspended sediment load and low visibility depths. As a result of strong water level fluctuations, the riparian zone occupies relatively large areas. This results in special vegetation complexes of riparian pioneer meadows, riparian shrublands, reedbeds, floodplain grasslands, softwood floodplain woodlands and hardwood floodplains, which are habitats for typical and partly endangered river valley plants. Especially on the Elbe, but also on its tributaries, short-lived riparian pioneer flora consisting of beach grass and dwarf rush communities develop on gravel and sand banks as well as on mudflats in stillwater areas during low water. Characteristic species include strapwort (Corrigiola litoralis), Spergularia echinosperma, hyssop loosestrife (Lythrum hyssopifolia) and water mudwort (Limosella aquatica). Bidens radiata are found below the mid-water level. The shallow flooded areas are important nurseries for fish and amphibians. After the water recedes, extensive sandy areas and the silt deposits in the groyne fields then provide rich food sources for limicolas.
Still Waters and Siltation Areas
The area of still waters in the Biosphere Reserve is relatively small. Nevertheless, standing waters are particularly characteristic elements in the floodplain, to which a large number of plant and animal species are bound. These typical floodplain structures are particularly endangered by the reduced influence of floods on the floodplain as a result of development and embankment, as well as sedimentation processes and the filling in of small water bodies. Still waters can be found in various forms, often with well-developed aquatic and riparian vegetation. Some natural small water bodies exist in the floodplain area, such as bracks. These are oxbow lakes and flood channels cut off from the river and usually connected to the main course, as well as oxbow lakes and scours completely separated from the river, which are formed as a result of water erosion during floods. These water bodies are increasingly lost as habitats as a result of the decreasing river dynamic processes and the consequent lack of new formation.
The cross-state Biosphere Reserve Elbe River Landscape is of outstanding importance for the conservation and development of riparian forests. For example, there is a total of over 9,000 ha of riparian forests, including the largest contiguous hardwood riparian forests in Central Europe, which are located between Barby and Griebow in the Saxony-Anhalt part of the area. In the Mecklenburg sub-area, there are only about 180 ha of riparian forest. Riparian forests are among the most species-rich and particularly threatened biotope types in Central Europe. The hardwood riparian forests are habitat types protected throughout Europe according to Annex I of the Habitats Directive (FFH habitat type 91F0). The softwood floodplains of specific character even belong to the priority habitats (FFH habitat type 91E0). If the floodplain of the Elbe River Landscape were completely free of human intervention today, large areas along the Elbe River would be covered with extensive hardwood floodplain forests (the so-called "potential natural vegetation" of the river valley floodplains).
Quarry and Alder-Ash Forests
In contrast to riparian forests, quarry and alder-ash forests depend on a constantly high groundwater level and do not tolerate regular severe drought. Within the floodplain, which is characterised by fluctuating Elbe water levels, they therefore have only a limited natural distribution, e.g. in the low-lying, wet floodplain rim depressions. In the lowlands of the small Elbe tributaries, on the other hand, they are sometimes found in greater frequency. The quarry forests can be divided into the types alder quarry, birch quarry and pine quarry, the last two of which are priority habitats (FFH habitat type 91D0). Alder-ash forests along watercourses are also priority habitats (FFH habitat type 91E0). Alder-ash forests are usually only found in small areas along watercourses or at springs.
Alternating wet Floodplain Grassland
The floodplain grassland is characteristic of the Elbe floodplain and comprises many different plant communities depending on location, moisture or flooding duration, soil type and use. Due to its species-rich formation and subcontinental character, it is of particular floristic interest. In contrast to the "real" wet meadows, changing water levels with possibly considerable drying out at low water levels of the Elbe are typical. Characteristic meadow communities include Cnidium-meadows (FFH habitat type 6440), false oat-grass and burnet-/Selinum meadow (FFH habitat type 6510), compact dock/oxeye daisy-meadows and peavine-meadows. Floristically highly impoverished wetland grassland is found over large areas in the Elbe foreland and in the Qualmwasser zone. These stands are dominated by meadow foxtail (Alopecurus pratensis) and couch grass (Agropyron repens). Stands of well-developed stream valley meadow communities therefore only exist on a few areas. Other focal areas of floodplain meadows are also located in the floodplain of the Elbe tributaries Sude, Schaale, Rögnitz and Löcknitz.
A wet meadow is a mown or grazed grassland of permanently wet, often marshy sites. Typically formed wet meadows (marsh marigold meadows, cabbage thistle meadows, water-grass meadows) are found sporadically at the valley edge of the Elbe floodplain and in the tributary lowlands.
Wet pastures usually harbour fewer endangered plant species than wet meadows and only occur as standing pastures with continuous grazing and low stocking density in species-rich forms. When wet grassland falls fallow, moist tall herbaceous meadows, tall sedge meadows, reed canary grass meadows or reedbeds develop. In hollows within the grassland that have been flooded for a longer period of time, floodplain grasslands of low-growing, stoloniferous species develop.
Fresh Meadows and Fresh Pastures
There are still large numbers of fresh meadows and pastures, especially in the dyked and drained Elbe floodplain. Endangered are the typically distinctive, species-rich meadow and pasture communities that develop under extensive use (moderate fertilisation, two to three mowings) on lean and dry sites. Particularly rich in herbs and species are the dry and lean forms of the fresh meadows in the transition to the dry grasslands, e.g. over long stretches on the old Elbe dykes, as in the Rögnitz lowlands.
Dry Grasslands and Heathlands
Dunes, low plateaus and steep deforested valley slopes form the sites of rough grasslands, dry grasslands and heaths. Dry grasslands and heaths have a high value as habitats for reptiles (e.g. sand lizard), various insects (specialised grasshoppers, butterflies, ground beetles, antlions and Aculeata) or spider species. With the exception of areas used for military purposes (e.g. former military training area Lübtheen), these two habitats have usually been created by grazing nutrient-poor and dry areas with sheep or goats. This is often no longer economically viable today. Therefore, most of these areas disappeared, especially through afforestation and succession. The extensive nitrogen input from the air, which favours nitrogen-loving grasses and perennials over dry grassland plants, is a negative factor.
Due to the precipitation level, there are no naturally forest-free dry grasslands in the Biosphere Reserve, but acidic sandy dry grasslands, where the growth of shrubs is slowed down due to the low water-holding capacity of the soil and the poor nutrient supply, and is also repeatedly removed by human intervention (deforestation, grazing, mowing, fire, vegetation damage by driving or walking). A distinction can be made between patchy silver-grass meadows as pioneer communities and more or less closed botanically richer grass-clover meadows. Dry grasslands occur relatively small and scattered on dunes near the river and further away from the Elbe, mostly in the form of silver grass meadows, e.g. on the inland dunes near Gothmann and on the inland dunes near Klein Schmölen. As a special feature, junegrasses are occasionally formed on more base-rich sites (priority FFH habitat type 6120). Characteristic or protected species of the dry grasslands include the blue hair grass (Koeleria glauca), grey hair-grass (Corynephorus canescens), sea thrift (Armeria elongata), an Jurinea cyanoides.
Dry heaths of acidic sandy sites (e.g. Calluna heaths) were also only able to form on a significant scale due to human influence, especially on military training areas. Today, they occupy only a very small proportion of the area, mostly in the form of narrow bands along paths, and occur in large areas, e.g. on the former military training area of Lübtheen and now the National Natural Heritage Site of Lübtheener Heide. The dry heaths belong to the FFH habitat type 4030 according to Annex I of the Habitats Directive.
Fens are ground-, soil- or rainwater-dependent habitats that have developed varying degrees of peat thickness. They belong to the particularly endangered habitats which, in addition to their function as water, carbon and nitrogen reservoirs, also serve as habitats for many specialised animal and plant species. Within the floodplain, the fens cover only a small area and mostly occur at the valley margins. Most of the fens in the Biosphere Reserve Elbe River Landscape are located in the tributary lowlands, such as the Rögnitz. They are predominantly nutrient-rich fens in the lowland areas of the Elbe tributaries, which can be characterised as siltation bogs, and more rarely as flow-through or spring bogs. The fens are generally degraded by drainage measures.
Marsh- and Dune Fens
Examples in the Mecklenburg sub-area are the eutrophic marsh "Trebser Moor" and small-scale fens such as the dune valley fen "Die Bank" near Woosmer. The fens are classified as FFH habitat types 7140 (transitional and oscillating grassland fens) and 7120 (degraded raised bogs still capable of renaturation). Typical representatives of the flora include bottle sedge (Carex rostrata), common cottongrass (Eriophorum augustifolium), purple marshlocks (Potentilla palustris), early marsh-orchid (Dactylorhiza incarnata), tufted loosestrife (Lysimachia thyrsiflora) and various peat mosses (Spaghnum spec.). Wooded bog areas support alder scrub and bog birch-alder quarry forests.
Threats to peatland sites occur as a result of drainage measures and groundwater lowering, eutrophication, intensification of grassland use in peatland areas (frequent mowing, fertilisation), grassland conversion and afforestation. The mostly isolated location and small size of the fens is also problematic.