Baumberge (Berlin)
The Baumberge (in the vernacular also excavator mountains or sand mountains ) are an inland dune landscape in the landscape protection area Tegeler Forst in the Berlin district Heiligensee ( district Reinickendorf ). Like other inland dunes, the Baumberge were blown up at the end of the Vistula and Würm glacial periods , i.e. a little over 10,000 years ago.
The area covers an area of 46.95 hectares and is protected as a protected area by the European Fauna-Flora-Habitat Directive and part of the transnational protected area system Natura 2000 . The decisive factors for this are the open dune areas and dry grassland communities , which are viewed as valuable in terms of plant geography and particularly worthy of protection. In addition to the dry grasslands, the area includes warmth-loving shrubbery and pre-forest communities as well as plant communities of moist to wet areas at the Lingenpfuhl in the southwest part of the Baumberge.
geography
location
With a total area of around 47 hectares, the Baumberge are part of an area of drift sand on the northern edge of the Berlin glacial valley , which extends between the Tegeler and Spandau forests . The entire area is cut up by the Havel , which separates the basement moraine plates of the Barnim in the east from the Ländchen Glien in the west. The entire area is assigned to the Mecklenburg-Brandenburg plateau and hill country natural space unit.
They are located in the southern part of the Tegeler Forst landscape protection area (LSG 2b: Tegeler Forst, southern part) in the Berlin district of Heiligensee on the northwestern outskirts of Berlin. In the north, the area is closed by the Elchdamm, to the north of this there are several single-family housing estates , including the allotment garden “Waldessaum”, as well as a larger agricultural area. North of the allotment area is still known as Natural Monument excellent Bumpfuhl .
A short spur road extends from the Elchdamm into the Baumberge and connects the school camp located in the nature reserve with the road. The eastern and southern borders of the Baumberge are represented by the forest area of the Tegel Forest, in the west there is also a soccer field on the border of the nature reserve.
Dune formation in the Berlin glacial valley
Like numerous dune formations in Berlin and Brandenburg, the tree mountains emerged after the glaciers melted after the last ice age . After the ice cover had disappeared and due to the lack of vegetation , the sandy areas beneath the ice were exposed to very strong winds, especially from the west. These mainly transported dust and fine sands from the Berlin glacial valley to the east, where they formed hills and finally shifting dunes with sand heights of over 30 meters above the valley sands. Since the wind came from the west, the dunes generally run in a west-east or north-west-south-east direction and have the shape of parabolas or they represent wide, undirected sand areas.
This process was already completed in the Late Ice Age about 12,000 years ago, as a protective vegetation of juniper , sea buckthorn and willow formed on the dunes after a pioneering society of fortifying grasses (willow-sea buckthorn-juniper period). The further migration was prevented, at the same time the influx of sand decreased more and more. The vegetation continued to increase and over a long process of succession most of the dunes, with the exception of the Baumberge, were completely overgrown with the mixed beech forest typical of Berlin's forests. The Baumberge, on the other hand, developed into an open dune due to their historical use.
ground
The thickness of the dune sand is a few decimeters to a maximum of 20 meters at the highest dune points. The highest elevation of the dunes is 62 meters above sea level, the lowest in the Lingenpfuhl area is 32 meters above sea level. These are light-colored sands with a very high proportion of fine sand ( drifting sands ) that are free of lime except for a few places. Embedded are humus strips of fossil vegetation as well as the osteocollas typical of the Berlin area , calcified tree roots.
In the dune valley areas, fine-grained valley sands with carbonate layers and silt-rich loam come to the surface. The entire area is underlain by these valley sands and boulder clay.
Climate and groundwater
The climate of the area essentially corresponds to the climate in Berlin: The city is located in the temperate climate zone with an average annual temperature of 9 ° C (at the measuring point in Berlin-Dahlem 8.9 ° C) and an average annual rainfall of around 600 mm . The amount of precipitation in the tree mountains as well as in the surrounding forests is somewhat higher than in the inner city of Berlin due to evaporation in the forests. The warmest months are July and August with an average of 18.5 and 17.7 ° C and the coldest January and February with an average of −0.6 and −0.3 ° C. Most precipitation falls in July, the least in March.
In the areas around the Lingenpfuhl, groundwater comes to the surface. However, since the tree mountains are located in the area of the lowering funnel of the Tegel waterworks , the groundwater level was lowered in the entire area, which was estimated at just under one meter for the period from 1959 to 1984 and, as a result, a change in the vegetation at the Lingenpfuhl from backwater-dependent large sedge- Societies led to bush pioneer societies.
Usage history
The development of the Heiligensee settlement, then called “Hyelegense”, dates back to the early 13th century. The settlers called into the country by the Ascanian margraves cleared large areas of the forests around the mountain in order to create areas for fields and pastures. They cleared other areas specifically in order to gain heathland for the beekeepers. Trees were just standing on the hills, so that they are the mountains with trees, as Baumberge distinctive, stood out from the forest-free environment. The name “Bumberg” appears on the oldest known map of the Heiligensee field from 1739. This use only declined in the 19th century and only around 1875 did a young forest exist on the Baumberge, which around 1910 was indistinguishable from the rest of the Tegel Forest on city maps.
In 1928 the Baumberge were used as a sand extraction point for the construction of the Kremmener Bahn and for the partial drainage of the Bumpfuhl and made accessible through two large forest aisles. During the Second World War there was again extensive clearing and after the end of the war the tree mountains were used as a training area for the French allies until the troops withdrew in 1994 , and the use of tracked vehicles prevented tree growth. Illegal motocross races and similar uses also meant that the open dune areas remained ungrown.
The Baumberge are a popular excursion and recreation area and are influenced by their use with small settlements, playgrounds and garbage areas as well as the school camp located in the area. This use was reduced from 1994 by efforts to protect the area, but it still exists and has been partially integrated into the protective measures.
Flora and fauna
Plants and plant communities
The open dune areas of the Baumberge are characterized by sandy heaths and dry grass communities on nutrient-poor, predominantly lime-poor sands. These plant communities are considered to be particularly worthy of protection, although the subcontinental blue schiller grasslands found here are rare in Europe.
The moors by the historically developed by clearing are heather (Calluna vulgaris) and gorse species (Genista) as the hairy gorse (Genista pilosa) marked. The open sand areas are covered with the sand sedge (Carex arenaria) belonging to the sour grasses , which, as a pioneer plant, strengthens the entire dune with its meter-long foothills. This enables the settlement of other dune plants such as the heather carnation (Dianthus deltoides) , the hawkweed (Hieracium pilosella) and the beach carnation (Armeria maritima) .
There are also open grass corridors with silver grass (Corynephorus canescens) and red ostrich grass (Agrostis capillaris) . The blue-green schillergrass (Koeleria glauca), which gives it its name, determines the blue-green schiller- grass corridors bound to soils rich in bases .
Rare plant species that are threatened with extinction in the state of Berlin and endangered nationwide are the violet salsify (Scorzonera purpurea) , the gray scabiosa (Scabiosa canescens) , the common (Pulsatilla vulgaris) and the pasque flower (Pulsatilla pratensis) and the green-flowered Catchfly (Silene chlorantha) .
The southwest part of the Baumberge is characterized by the Lingenpfuhl , a small body of water, and is home to plant communities of moist to wet areas. In particular, the transition areas to the edge of dunes and the overgrown dunes shares are with the typical for the Tegel forest pine and grape (Quercus petraea) and common oak (Quercus petraea) forested.
Animals
Among the animals, numerous insects and other invertebrates are worth mentioning, which as xerothermophilic species prefer particularly dry and warm habitats. There is a rich fauna with stony ground beetles , spiders , grasshoppers , butterflies and stinging voices . The sand earwig (Labidura riparia) and the dune tiger beetle (Cicindela hybrida) are particularly well-adapted species of the dune . Among the grasshoppers, the gravel bank grasshopper (Chorthippus pullus), which is endangered nationwide, is noteworthy. In addition, all three ant maids that are native to the Berlin area can be found in the tree mountains, including the dune ant maiden (Myrmeleon bore) , which was only detected on the Windmühlenberg in Gatow and in the spruce meadow on the northern edge of the Spandau Forest .
Protected vertebrate species in the reserve are the sand lizard (Lacerta agilis) in the dry habitats and the common toad (Pelobates fucsus) in the Lingenpfuhl area. Due to the small size of the sand dune area, the species spectrum of birds and mammals corresponds to that of the Tegel Forest and other forest areas in Berlin that use the tree mountains as an open structure of their habitat.
Nature reserve
In addition to the Baumberge inland dune, there is another inland dune in Berlin, the Wilhelmshagen-Woltersdorfer dune range , with open dune areas and dry grass communities on nutrient-poor, predominantly lime-poor sands. As a result, the Baumberge were recognized as a protected area of the European Fauna-Flora-Habitat Directive and part of the transnational protected area system Natura 2000 .
Plant communities that are particularly worthy of protection (Annex I of the Habitats Directive) are named:
- 2310 sand heaths with Calluna and Genista
- 2330 Dunes with open grass corridors from Corynephorus and Agrostis
- 6120 Subcontinental blue schiller grasslands
- 9190 Old acid oak forests on sandy plains
In particular, the protection of the subcontinental blue shrub grasslands is classified as a priority. According to Appendix IV, the sand lizard (Lacerta agilis) and the common toad (Pelobates fucsus) are particularly worthy of protection in the area .
The use of the Baumberge as a recreational area resulted in a sharp decline in xerothermophilic invertebrate animal species up to 1994 and the plant species worthy of protection were only available in remnants. The loss of the rare silver grass fields and dwarf shrub heaths, which are particularly worthy of protection, was particularly severe due to drifting sand and the increasing eutrophication of the area due to overfertilization. The latter led to the fact that dry sand lawns were converted into nitrogen-loving herbaceous areas in the peripheral areas.
The following points are defined by the authorities as protection goals:
- the preservation of the open dune locations as a habitat for the blue shrub grass lawns, heather and carnation meadows, silvergrass dry sand lawns, dwarf shrub heaths made from common heather and gorse and their promotion through targeted reduction of succession and prevention of overuse,
- the promotion and development of loose forest pine stands on xerothermal locations with ground vegetation rich in dry grass types and
- the preservation and development of acidic oak forests on sandy plains, provided they do not compete with open dune locations.
In order to prevent the natural succession of the open dune areas and a corresponding overgrowth, trees must be removed at regular intervals. This succession begins with larger fields of land riding grass (Calamagrostis epigejos) and pioneering trees such as the trembling poplar (Populus tremula) , the black locust (Robinia pseudoacacia) and the pines typical of the surrounding forest, which are displacing the drying specialists. Entry into and continued use as a recreational area should also keep the dune areas open, with particularly protected areas being delimited by barriers.
literature
- Senate Department for Urban Development Berlin: Berlin of course! Nature conservation and NATURA 2000 areas in Berlin. Verlag Natur & Text, Berlin 2007, p. 100ff. ISBN 978-3-9810058-3-7
- Birgit Lehmann: Historical development of the tree mountains in Berlin-Heiligensee. Berliner Naturschutzblätter 36 (1), 1992; Pp. 5-16
- Berliner Landesarbeitsgemeinschaft Naturschutz e. V. (BLN): List for the subsequent registration of protected areas according to the Habitats Directive for the State of Berlin from the Berlin nature conservation associations. P. 6–9 ( PDF download ; with a detailed list of references)
Web links
Individual evidence
- ^ Christoph Saure: Contributions to the knowledge of the animal world of Berlin (West). Part IV: ant maids (Planipennia, Myrmeleonidae). Berliner Naturschutzblätter 34 (3), 1990; Pages 23-29
- ↑ Database of the FFH areas (search for "Baumberge")
- ↑ to Berlin Senate Department for Urban Development: Subjects of protection
- ^ Senate Department for Urban Development Berlin 2005
Bäkewiese | Barssee and Pechsee | Mountains of trees | Bogenseekette and Lietzengraben lowlands | Former airfield Johannisthal | Eiskeller and Spandauer Luchwald | Falkenberger Rieselfelder | Lazy Lake | Flow meadow Ruhleben | Fort Hahneberg | Big and Small Rohrpfuhl | Big Fenn | Grünauer Cross | Grunewaldsee (southern part) | Dog throat | Idehorst | Imchen Island near Kladow | Tufa limestone site on the Tegeler Fließ | Karower ponds | Krumme Lake Grünau | Langes Luch / Dachsheide | Malchower Aue | Middle break | Müggelsee and Fredersdorfer Mühlenfließ | Müggelspreeniederung Köpenick | Murellenschlucht and Schanzenwald | Meadows on the Tegeler Fließ | Peacock Island | Postfenn and Teufelsfenn | Riemeisterfenn | Sandpit in Hunting 86 of the Grunewald | Buch Castle Park and adjacent wooded area | | Lichterfelde Palace Park | Schöneberger Südgelände | Tegeler Fliess | Teufelsbruch and side moors | Teufelsseemoor Köpenick | Toad puddle Marzahn | Wartenberger / Falkenberger Luch | Johannisthal waterworks | Wilhelmshagen-Woltersdorfer Dune Train | Windmühlenberg | Ziegeleigraben / Albtalweg
Coordinates: 52 ° 36 ' N , 13 ° 14' E