Stromtalwiese
The “ Stromtalwiese ” is the name given to the alternately moist grassland communities of the Brenndolden - wet meadows , also called Brenndolden-Auenwiese, (Cnidion) in river valleys.
The extremely different water levels are characteristic of the ecology of these meadows. Floods that last for weeks at the time of the snowmelt in spring and early summer flood the river valley meadows. On the other hand, in the hot, dry summer of continental Eastern Europe, the soils often dry out significantly, even in the floodplains .
So only species can survive that tolerate weeks of flooding as well as the stress of weeks of dehydration.
Their main distribution is in the river plains of continental Eastern Europe , where they extend from the Pannonian Basin, via Poland , Ukraine and European Russia to far south Siberia .
Plant society
The burnt umbel wet meadow is a species-rich, moderately nutrient-rich meadow community. It is mostly unfertilized or poorly fertilized, but has a medium yield potential due to the natural fertilization of the floods. The yield of 350 to 600 g dry matter per square meter and year is in the middle of the grassland communities. Burning cones wet meadows are very easy to convert into more productive, but significantly poorer species of grassland by fertilization.
The plant community consists of wet-tolerant swamp and flood lawn species, mesophytic grassland species and, on the other hand, distinctly drought-tolerant species from steppe lawns and fringing communities. A number of extremely rare and endangered plant species from Central Europe have their main distribution center or even their only occurrence in hot umbels wet meadows.
Common types of grass are meadow foxtail ( Alopecuros pratensis ), couch grass ( Elymus repens ) and meadow bluegrass ( Poa pratensis agg, in the small species Poa angustifolia ). In southern Germany existing stands with a lot of pipe grass ( Molinia caerulea agg., Small species Molinia arundinacea ) form transitional stands to the litter meadows . Typical types of Cnidium-marsh area are Allium angulosum , Arabis nemorensis , Carex melanostachya , Cnidium dubium , Veronica longifolia ( syn. Pseudolysimachion longifolium ), Scutellaria hastifolia , Viola persicifolia and Viola pumila . (Almost all of these species are threatened with extinction in Germany and are listed on the Red List of Threatened Plant Species). Most of the characteristic species of the meadow community bloom quite late in the year and give it a distinctive, colorful midsummer aspect.
The structure and position of the burning cones wet meadows within the plant-sociological system are understood differently. Oberdorfer describes a large number of associations, mostly regionally widespread, in southern Germany. Today, these are often united in a single broad society, the Cnidio-Deschampsietum cespitosae, which would then be the only Central European association of the association.
Distribution in Germany
Similar conditions as in the main continental distribution area of the meadow society can be found in the catchment area of the dry-warm, climatically already clearly subcontinental tinted large river valleys of
- Or , (middle and lower Oder valley)
- Elbe , (Middle Elbe and rivers of the Central German dry area: Elster, Mulde, Saale)
- Havel
- northern Upper Rhine ,
- of the middle Main (dry area around Schweinfurt) and the
- Lower Bavarian Danube (below Regensburg)
In these areas burnt umbel meadows are common in Germany. The northern Upper Rhine Plain forms the absolute western limit of its distribution. Wet meadows, which are close to the Cnidion, but are already clearly depleted of characteristic species, can still be found in France (rivers of the Champagne: Seine, Marne, Aube, Saone).
fauna
The fauna of the burnt umbel wet meadow is similar to that of other species-rich wet meadow communities. Similar to the plant world, soil-dwelling species, e.g. B. the ground beetles , a juxtaposition of wet meadow species and heat-loving species. Characteristic of this type of meadow in the Upper Rhine Plain is the occurrence of the grasshopper type leek insect ( Mecostethus parapleurus , syn. Parapleurus alliaceus ). Rare and threatened bird species are z. B. the corncrake or the reed warbler .
natural reserve
Burning umbels wet meadows are threatened with extinction in Germany. As with most near-natural grassland communities, the main cause is structural change in agriculture. The meadows were ameliorated by fertilization or turned into fields under the protection of new flood dikes. Where this was not possible or not worthwhile, cultivation was given up entirely and the meadows were abandoned. Across Europe, the burning cone meadow is a protected habitat type according to the Habitats Directive of the European Union. Almost all of the remaining stands of this type of grassland are in nature reserves. However, this (formal) protection is not sufficient to maintain them. Meadows, as use-dependent ecosystems, require ongoing, adapted use where this is no longer possible or unprofitable, and appropriate maintenance. In times of tight public budgets, ensuring this is not easily possible, even in protected areas.
The reclamation of burnt cone wet meadows on previous sites that have been destroyed by intensive use is difficult, as the characteristic species only spread slowly and would probably take centuries to repopulate. In the Upper Rhine there are promising approaches to restore the meadow type by transferring the mowing material from the existing meadows to the areas to be renatured - this acts like an indirect sowing of the species concerned.
literature
- Liepelt, S .; Suck, R. (1989): The river valley meadows and their characteristic species in Rhineland-Palatinate - a protection and care concept . Contributions to the state maintenance of Rhineland-Palatinate 12: 77–175.
- V. Kummer, Michael Burkart : The flora of the river valley meadows on the Lower Havel and other botanical features . In: Landesanstalt f. Large protected areas (Ed.): Havelreport I (1996), pp. 30–39
- Burkhart, M., Dierschke, H., Hölzel, N., Nowak, B., Fartmann, T. (2004): Synopsis of the Plant Societies in Germany . Book 9: Molinio-Arrhenatheretea. Part 2: Molienietalia. Published by the floristic-sociological working group and the Reinhold-Tüxen-Gesellschaft (Göttingen)
- Oberdorfer, E. (Ed.) (1983): South German Plant Societies. Part III. Stuttgart / New York (G. Fischer) 2nd edition. ISBN 3-437-30386-4