Bullenkuhle (moor)

Bull's Hollow
	View of part of the Bullenkuhle in early summer; a so far not overgrown deep bog still makes up about 10 percent of the bog area
Geographical location	Sprakensehl , Gifhorn district , Lower Saxony
Location close to the shore	Uelzen
	Data
Coordinates	52 ° 48 ′ 47 " N , 10 ° 31 ′ 1" E Coordinates: 52 ° 48 ′ 47 " N , 10 ° 31 ′ 1" E
Altitude above sea level	97 m above sea level NHN
surface	0.4 ha
length	85 m
width	60 m
particularities	Lake, largely muddy, created by sinkholes
	Location of the bull's hole and geomorphological profile of the area

The Bullenkuhle is a mostly boggy small lake in the far north of the Lower Saxony district of Gifhorn in Germany .

The peculiar biotope and geotope has formed in a natural hollow terrain that can be described as a sinkhole . The area is under nature protection.

Location, natural space

The Bullenkuhle is located about 15 kilometers south of the city of Uelzen and a good one kilometer west of the village of Bokel (municipality of Sprakensehl ) on the edge of a large pine forest complex at an altitude of 97 m above sea level. NHN . In the immediate vicinity rises a river, initially known as the “Bokeler Bach”, which later becomes the “Aue”, from Stederdorf to Stederau and finally, after merging with the Gerdau , becomes the Elbe tributary Ilmenau . In terms of natural space , the area belongs to a south-eastern foothills of the Hohe Heide , which in turn is a central part of the main unit of the Lüneburg Heath . This landscape, consisting of terminal and ground moraines as well as periglacial drifting sands, was geomorphologically shaped by the ice edge layers during later phases of the Saale Ice Age, namely in the so-called Drenthe II stage and the final Warthe-stadial glacier advance. The undulating ridges of the terminal moraines are mostly afforested with pine forest in the hilltops on predominantly sandy soils; the ground moraines are used for agriculture. An open heathland landscape that was assumed to be typical for the Lüneburg Heath - which, however, was anthropogenic due to timber harvesting, burning, pest removal and grazing - is only preserved today in fragments in the vicinity of the Bullenkuhle. The major climate of the Lüneburg Heath is sub- Atlantic .

Formation of the sinkhole

In northern Germany there are numerous underground salt domes - remnants of the “Zechstein Sea” from the Permian Age , which were later tectonically relocated and deformed. If the rock salt comes into contact with groundwater, leaching phenomena occur; salt is dissolved in the water and removed. This can result in the formation of large cavities, which ultimately cause the overburden above to collapse. In some cases, such a collapse, which takes place a few hundred meters deep, continues to the surface of the earth. There are then striking, often steep-walled and deep hollow forms, which are called "sinkhole". Some of these funnels remain dry, in others a body of water develops that can later become boggy. Geologically, sinkholes are often very young; it is not uncommon for them to be only a few thousand years old, and some intrusions were even only a few hundred years ago.

There are various examples of sinkhole lakes and moors in northern Germany, including quite large bodies of water such as the Arendsee and the Zwischenahner Meer - both over 500 hectares in size - the Seeburger See , the Sager Meer in the district of Oldenburg , the Rudower See in the district of Prignitz or the moors Groundless in the district of Heidekreis and Maujahn in the district of Lüchow-Dannenberg . The “Bullenkuhle” also belongs to this series, although it is much smaller. This sinkhole has a diameter of about 100 meters and reaches a depth of 15 meters. No information is available on the exact time when the bull's hollow was created; this would require a moor stratigraphic and pollen analysis of the vertical sinkhole profile (cf. Maujahn-Moor ).

description

The bull's hollow in early spring

A basin-like terrain structure opens up to the visitor with partly steep slopes (approx. 30 to 60 °). At the foot of the embankments made of sediment sand, a moor extends over an area of about 0.4 hectares, which on closer inspection turns out to be a floating or vibrating lawn, under which there is probably no homogeneous peat body, but at least partially a free body of water. The vibrating turf today covers almost 90 percent of the water or bog; only in the north-east is an approximately 400 m² large, several meters deep pond, a so-called moor creek, that has remained open. With an electrolytic conductivity of 24 µS / cm, the water is markedly oligotrophic , rich in humic substances and moderately acidic with a pH value of 5.0. Plants typical of bog grow in it, such as peat moss , water hose and the rare shiny water lily ( Nymphaea candida ). The swinging lawn penetrating into the Kolk consists of peat moss and mainly of Scheidigem cotton grass , bell heather , broom heather and crowberry heather ; and White beak-sedge and Ordinary Cranberry occur. The largely wood-free area can be characterized as a flat to barely arched intermediate moor. A ring-like rim swamp has formed on the periphery, which is supplied with slightly better nutrients than the center of the bog due to the rainwater flowing in from the slopes. The reed of the beak-sedge thrives here .

The slopes of the terrain funnel are occupied by dwarf shrub societies consisting of common heather, blueberry and lingonberry , pipe grass and woody plants. Among these, some very large and old juniper bushes or trees are particularly characteristic of the landscape. In addition, birches , buckthorn bushes and Scots pines should be mentioned in particular . Some of the animal world also specializes in moorland biotopes. Remarkably, among other things, the presence of up to eight species of amphibians and the viper .

The legend of the bull's hole

“In the place of this hollow there used to be a farm whose owner was a passionate hunter. For weeks the hunter had been chasing a big stag to bring him down. He was on the prowl day and night and hardly paid any attention to his farm.

One morning, when the hunter was sitting at table with his family and his servants, he said, to the horror of the family: 'If I don't keep a stag, stupid Hus un Hoff unnergahn!' When he returned home that evening without any prey, his curse was fulfilled. The yard with all its servants and all animals sank; only a black bog pond today indicates the place where the courtyard had stood.

But his breeding bull, which had broken out in the afternoon, escaped the accident. From now on the bull haunted Bokel and disappeared into the bull's hole in the evening.

One day the old shepherd Marten Heitzken set his dogs on the bull. But he attacked the shepherd. In agony the shepherd shouted: 'Joseph and Maria help me!' As if swept away by a magic hand, the bull disappeared into the hollow and was never seen again. To thank his salvation, the shepherd carved an oak door for the Bokeler chapel in 1631, which is still a witness of what happened at that time. "

protection

Because of its uniqueness as a biotope and geotope, the Bullenkuhle was designated as a nature reserve and, as an FFH area, is part of the European Natura 2000 system of protected areas . The protected area covers 2.55 hectares. Entering the vibrating lawn, which is sensitive to footsteps, is not only dangerous, it is also prohibited. To preserve the moorland, emerging pine trees are occasionally removed by landscapers. In a few decades or even centuries the entire water surface was likely to have been overgrown by the moor cover.

literature

J. Delfs: The Bull's Hollow . In: Nature reserves in the Gifhorn-Wolfsburg area . 1986
R. Pott: Lüneburg Heath . Excursion guide cultural landscapes, Ulmer-Verlag, Stuttgart 1999, ISBN 3-8001-3515-9
R. Tüxen: The bull's hollow at Bokel . Treatise natural science Ver., Bremen 1958, 35/2: 374-394
Ernst Andreas Friedrich : Natural monuments of Lower Saxony . Hanover, 1980. ISBN 3-7842-0227-6
Eberhard Rohde: The legend of the Bullenkuhle in: Legends and fairy tales from the Gifhorn-Wolfsburg area , Gifhorn, 1994

Web links

Commons : Bullenkuhle - Collection of pictures, videos and audio files