Am Hornpottweg nature reserve

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Am Hornpottweg nature reserve

IUCN Category IV - Habitat / Species Management Area

View of the former gravel pit in winter

View of the former gravel pit in winter

location Cologne , North Rhine-Westphalia , Germany
surface 41 ha
Identifier NSG K-014
WDPA ID 162161
Geographical location 51 ° 1 '  N , 7 ° 2'  E Coordinates: 51 ° 1 '0 "  N , 7 ° 2' 20"  E
Am Hornpottweg nature reserve (North Rhine-Westphalia)
Am Hornpottweg nature reserve
Sea level from 37 m to 60 m
Setup date 1989
Framework plan Landscape plan city ​​of Cologne
administration Lower landscape authority of the city of Cologne

The nature reserve "Am Hornpottweg" (also known as Hornpott-Kiesgrube ) is located on the northeastern edge of Cologne , near the city limits between Cologne-Dünnwald and Leverkusen-Schlebusch , at an altitude of about 55 meters above sea ​​level . The approximately 27.6 hectare area, which includes the former gravel pit (17.8 hectares) and adjacent forest areas , has been a nature reserve since 1983 and represents one of the most valuable biotopes in the city limits of Cologne. It is part of the Bergische Heideterrasse .

history

Information board of the nature reserve

The approximately 445 m long, 400 m wide and 10 m deep gravel pit near Hornpottweg, a road that runs through the middle of the Dünnwald forest , was to be filled in again after its closure in 1976. However, the rise in groundwater created larger pools of water in the pit , which favored increasingly diverse vegetation , which in turn led to more and more migratory birds resting in the pit, some of which were already registered on the red list . This development prompted conservationists, especially the associations DBV (later NABU Cologne) and BUND in Leverkusen , to apply in 1980 to the district president of Cologne, Franz-Josef Antwerpes, to secure the former gravel pit for nature conservation. An agreement was only reached a few years later, the mine was acquired by the State of North Rhine-Westphalia and placed under nature protection as a wetland biotope in 1983 . The pit itself has been fenced in since then and is not allowed to be entered, but it can be seen from a circular path that surrounds it, about two kilometers long. In addition to protecting the actual pit, Hornpottweg was closed to motor vehicle traffic in 1993 in order to better protect the common toads , common frogs and pond newts from cars.

Flora and fauna

Since it was designated as a nature reserve, the Hornpott gravel pit has developed into an important habitat for numerous animals and plants. The frequent strong fluctuations in the water level in the pit, which among other things depend on the water level of the Rhine , which is around 4.2 km away, as well as the amount of precipitation , regularly change the size of the water pools, which has an impact on life there: For example, when the water level is particularly high, several pools merge to a single, about six hectare water area with several small islands, which offers especially water and diving birds favorable conditions for foraging, while waders benefit from a low water level in particular , who find favorable breeding opportunities in the muddy land areas that then form.

However, a rich animal and plant population developed not only in the pit itself, but also on its slopes, which are overgrown with dense slopes of willow , blackberries and other shrubs. The nature reserve also includes adjacent forest areas that form a mixed forest with a relatively high proportion of pines and birches , which are particularly common in the entire Dünnwalder forest due to the sandy soils in this area. Overall, the range of different habitats that occur here extends from reed beds to grassland to small-scale sand-poor grassland , which forms in drought, as well as wooded areas. The rather rare plants that can occasionally be found in and around the pit include, for example, the swamp iris or the water knotweed ; Until a few years ago, the heather carnation was found on dry areas of the area .

The abundant planting, as well as the generous fish stocks in the pools of the pit as well as numerous occurrences of dragonflies , hay horses and butterflies , provide a habitat for a number of bird species - so far over 200 species have been spotted here more or less often (see also the section " Registered bird species " below ) ). Of these, around 110 species are on the Red List of Endangered Species for North Rhine-Westphalia . One example is the osprey , which rests here on its hikes in spring and autumn. The numerous gray herons and cormorants feed on fish in the waters of the pit . The bird species that breed here regularly or irregularly include the little ringed plover , the lapwing and the blackcap . At different times of the year, with more or less luck, you can watch birds resting in the former gravel pit; including the tree falcon , the hawk , the kingfisher and the hen harrier , as well as various migratory birds that use the pit as a resting place when they fly over. The hedges around the pit also offer many birds good breeding opportunities.

Besides birds, the Hornpottgrube also offers a habitat for other animal species. In addition to the numerous common toads and other frogs , there are other smaller animals such as the sand lizard , the wood mouse and numerous bats . Deer and foxes can often be seen in the pit .

Another specialty here are the Glan cattle , which have been relocated to the Hornpottgrube every year from spring to autumn since 1994 from the Wahner Heide . Thanks to this grazing, it was possible to dispense with some of the time-consuming maintenance measures that had been necessary up until then, such as mowing and removing bushes in the marginal areas, some of which were difficult to access, in order to prevent uncontrolled growth and the associated displacement of some species. The monochrome brown animals, which belong to the old Rhenish breed of "Glanviehs", feed exclusively on the vegetation found here, the calves are suckled by their mothers and grow up in herds. The ecological effects of this so-called "extensive grazing", which is also carried out for similar purposes in the Wahner Heide, are scientifically observed.

The uniqueness of the Hornpottkiesgrube as a nature reserve consists not only in the great wealth of various animal and plant species, but also in the diverse observation possibilities that are open to the visitor. Since almost the entire pit can be seen from several points on the circular route, many of the animals living here can be viewed “in the wild” with or without binoculars, which is not possible in many other biotopes. This is mainly possible because of the dense, impassable embankments on the mostly very steep slopes of the pit, which thus form a sufficient buffer zone even for the most shy animals. The nature reserve "Am Hornpottweg" can also be explored during one of the guided tours that are occasionally offered by local nature conservation associations.

Problems

Overview map of the nature reserve

The actual area, designated as a nature reserve, was supplemented a few years ago on the north side by the so-called “Bullenwiese”, a large field and meadow area that lies in the Leverkusen city area. This area was also occasionally used by some migratory bird species to rest, and the gray herons hunted mice here when the water level in the pit was too high. Since 2004, however, this area has been almost continuously built on by a new industrial park . This fact met with sharp criticism from nature conservation associations, as they fear a loss of habitats and consequent impoverishment of the fauna in the nature reserve due to the increasing penetration of residential and commercial areas near the Hornpottgrube.

Registered bird species

The following list lists all bird species that were registered by the Biotope Networking Working Group in the area of ​​the nature reserve "Am Hornpottweg" and the adjacent "Bullenwiese" during the observation period from 1984 to 1999 . A bird species was always classified as an “exceptional guest” if it could only be observed up to five times during these 15 years. Bird species that are now listed as “critically endangered”, “threatened with extinction” or “extinct” in the Red List for North Rhine-Westphalia and which are rarely or not at all in the “Am Hornpottweg” nature reserve are marked with *.

Year-round guests

Guests at train times

Regular migrants

Regular winter guests

Regular breeding birds

Rare migrants

Rare winter guests

Irregular breeding birds

Exceptional guests

See also

Web links

Commons : Naturschutzgebiet Am Hornpottweg  - collection of images, videos and audio files

literature

  • Hermann Josef Roth (Ed.): Kölner Naturführer , pp. 269–273. Cologne 1991, ISBN 3-87909-256-7
  • Christian Wolf, Hermann Brombach and Ingo Fahne: The Hornpottweg gravel pit - nature and nature conservation in the conurbation . Cologne 1991