Aitrach gravel pit (nature reserve)

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Aitrach gravel pit nature reserve

IUCN Category IV - Habitat / Species Management Area

View of the east bank of the northern quarry pond in the nature reserve Kiesgrube Aitrach

View of the east bank of the northern quarry pond in the nature reserve Kiesgrube Aitrach

location Aitrach in the district of Ravensburg , Baden-Württemberg , Germany
surface 13.4 ha
Identifier 4318
WDPA ID 378108
Geographical location 47 ° 56 '  N , 10 ° 5'  E Coordinates: 47 ° 56 '2 "  N , 10 ° 5' 14"  E
Aitrach gravel pit (nature reserve) (Baden-Württemberg)
Aitrach gravel pit (nature reserve)
Sea level from 591 m to 610 m
Setup date October 17, 2007
administration Regional Council Tübingen

The Kiesgrube Aitrach area is a nature reserve (NSG number 4.318) designated by ordinance of October 17, 2007 of the Tübingen regional council in the area of ​​the Baden-Württemberg community of Aitrach in the Ravensburg district in Germany .

location

The approximately 13.4 hectare gravel pit Aitrach nature reserve is naturally located between the Untere Illertal (natural area 44) and between the Riss-Aitrach slabs (natural area 41) (exactly 41.3 gravel channels and old moraine slabs in the Adelegg area). These natural spaces belong to the Donau-Iller-Lech-Platte . The nature reserve is located southwest of the residential buildings and the gymnasium and festival hall at an altitude of 591 to 610  m above sea level. NN .

Geology, hydrology and climate

The subsoil of the site consists of upper freshwater molasses (OSM) . The river Aitrach dug a canyon about 90 meters deep into this OSM between the Riss and Würme Ice Age. During the Worm Ice Age, the edges of the canyon eroded and filled it up to a height of about 30 m. The melt waters of the eastern Rhine glacier, which flowed in from the southwest, supplemented by the melt waters of the Iller glacier, gravel this canyon and the entire area. This gravel canyon ( Tief-Aitrach-Rinne ) is an excellent aquifer in which the second largest groundwater flow in Baden-Württemberg flows. As part of the gravel extraction, this aquifer was exposed in two places, creating two quarry ponds with an area of ​​approx. 2.5 and 2 hectares. The flow rate of the groundwater stream is 20 to 30 m per day. Due to the constant exchange of water, these lakes are among the coldest in summer and the warmest lakes in Baden-Württemberg in winter. The mean annual air temperature is 7 ° C, the average temperature in the growing season around 14 - 15 ° C. Depending on the slope, exposure, vegetation, nature of the subsoil and other topography, the microclimate within the nature reserve deviates significantly from the average values.

Appearance

The steep walls of the gravel pit are forested. In the eastern part of the gravel pit there are two large quarry ponds up to 12 m deep (2.5 and 2 hectares of water) through which the groundwater flows and therefore remain largely free of ice even in severe winters. In the middle part of the gravel pit there is a raw gravel area that has now been largely populated with willow. In the western part of the gravel pit there is a secondary primeval forest with a very high proportion of biotope wood. Within the protected area between the gravel pit and the railway line, there is another raw soil area. The former gravel mining area in the north and west is framed by an oak-hornbeam hillside forest, which lies on a low terrace erosion edge.

Protection purpose

Protection of the uninfluenced self-dynamic development on a large part of the area, especially in the area of ​​the lakes and to the east and north of it. Preservation of the quarry ponds fed by the groundwater as a habitat for endangered plant species and as a habitat for endangered animal species. Preservation of the north-east exposed, oak-hornbeam forest planted low terrace erosion edge as an example of a special geomorphological appearance that characterizes the landscape and represents a geological document. Preservation of the diverse secondary and replacement biotope in its entirety as a stepping stone between Aitrach and Iller. Securing of the lime-rich, nutrient-poor standing waters that occur in the area with chandelier algae. In 1997, 259 species of higher plants were recorded, including 4 endangered species in Baden-Württemberg and 11 species in need of conservation. 57 bird species were observed in avifauna mapping, 18 of which are on the Baden-Württemberg Red List. The area is of particular importance for process protection, which is only stated as a protective purpose in very few cases.

Danger

When planning the nature reserve in 1997, an area of ​​24.2 hectares was assumed. However, the designated NSG only has an area of ​​13.4 hectares. A sports and leisure area with a soccer field, grandstand, miniature field, beach volleyball court, children's playground and parking lot was built on one part. This part is irretrievably lost. The fertilization of the soccer field leads to an eutrophication of a formerly (1997) valuable approx. 150 m² large fine sludge area with intensive orchid occurrence (approx. 30 flowering specimens Dactylorhiza incarnata and approx. 65 specimens Epipactis palustris ). These have largely disappeared at this point. The nature reserve ends directly on the south bank of the southern quarry pond. The southern slope of the gravel pit was not included in the NSG because the route for the new construction of the state road 314 is planned in this area. The construction of this route or road would have a massive impact on the nature reserve. Recreational use (swimming, campfires, scooters) - despite the ban - has a negative effect on the breeding behavior of numerous bird species. A breeding bird survey by NABU Aitrach showed that in 2011, compared to 1997, there were no breeding occurrences of the following bird species: Tufted duck, gray woodpecker, green woodpecker, dunnock, swamp-reed warbler, yellow mocker, rattle warbler, blackcap, garden warbler, red-backed killer, common bird. The rosemary-leaved willowherb was dug up in the easily accessible places in the NSG. For this purpose, individual copies have settled in the parking lot.

Development potential

Behind the eastern slope of the nature reserve, a new, approx. 4 ha large quarry pond will be built by 2016, which is intended to be used partly for leisure purposes (swimming) and partly for nature conservation. As a result, on the one hand, the leisure pressure can be diverted from the nature reserve, on the other hand, new unfinished floor areas are created, whereas in the nature reserve the unfinished floor areas disappear due to permanent succession. The gravel mining in the neighboring area exposes sand lenses. Sand martins, whose colony exceeded 100 breeding pairs in 2013, create new breeding tubes in these.

Rosemary fireweed
Rosemary fireweed
Spotted orchid
Unfinished floor area
View from south to north over the northern quarry pond
Secondary primeval forest
Biotope wood
Southern quarry pond
Gravel extraction in the new gravel pit adjoining the NSG

Flora and fauna

flora

The following species (selection) from the flora worthy of protection are to be named:

fauna

The following species (selection) from the animal world worthy of protection are to be named:

History of the nature reserve

Created by NABU Aitrach

  • In 1924, the Deutsche Reichsbahn began mining gravel.
  • In 1936 gravel mining is expanded for the Ulm-Stuttgart motorway construction. The gravel extraction is still done by hand.
  • In 1939 the workers were needed as soldiers for the Second World War. A bucket ladder excavator is used to replace the lack of workers .
  • In 1944 the Zeppelin Works , Friedrichshafen build a 100 m × 35 m hall for armaments production. It will be forced laborers , which are housed in a bearing between the channel and the Aitrach Aitrach busy.
  • In 1957 wet mining began. Two quarry ponds up to 12 m deep will be created. The gravel washing creates a large alluvial surface in the north-western mining area.
  • In 1965 gravel mining is stopped. After that, only gravel storage and a partial filling with precast concrete takes place.
  • In 1978 the district office calls for recultivation for agricultural purposes. As a NABU member, the then managing director recognized the great ecological importance of the renaturation that had already taken place . Since agriculture is not interested in this area either, recultivation can be omitted.
  • In 1997 the Tübingen regional council commissioned an expert opinion. It shows in great detail (on 34 pages and with 5 maps) the high biodiversity of the flora and fauna as well as the outstanding importance of this area.
  • In 2000, the municipality of Aitrach acquired the land for nature conservation with financial resources from the state from the nature conservation budget.
  • In 2002 the municipality of Aitrach built a sports field on a part of it.
  • In 2007 the remainder of the former gravel mining area and the adjoining slope, a species-rich oak-hornbeam shadow forest with a high proportion of biotope wood , was designated by the district administrator as a nature reserve "Kiesgrube Aitrach". However, the southern slope is excluded. It should serve as a route for the future L314.
  • In 2008 the municipality of Aitrach, funded by PLENUM , set up a bird watching stand on the west bank of the northern lake. NABU Aitrach provides information about the nature reserve there.

See also

Individual evidence

  1. ^ Ministry for the Environment Baden-Württemberg (1989): "Hydrogeological Map Baden-Württemberg- Leutkircher Heide and Aitrachtal"
  2. ↑ a b c Burkhard Schall, Tübingen Regional Council (2007): Appreciation of the nature reserve "Aitrach gravel pit"
  3. ↑ a b c d e Ute Reinhard (1997): "Expert opinion on the protection procedure for the planned NSG"
  4. ↑ Volker Scherfose (edit.) (2011): “The German Protected Area System - Focus: Strictly Protected Areas”, BfN-Skripten 294, p. 175
  5. ↑ Meinrad Mack (2011): "Recording of breeding birds in the nature reserve Kiesgrube Aitrach"
  6. ↑ Norbert Rauh (2009): "History of the nature reserve gravel pit Aitrach"

Web links

Commons : Naturschutzgebiet Kiesgrube Aitrach  - Collection of pictures, videos and audio files