The Feldsee (also ''Feldbergsee'') is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

in southern

Baden-Württemberg Baden-Württemberg (; ), commonly shortened to BW or BaWü, is a German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants across a ...

at the foot of the Feldberg east of Freiburg im Breisgau in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. It is part of the

Southern Black Forest Nature Park The Southern Black Forest Nature Park (german: Naturpark Südschwarzwald) is located in Baden-Württemberg in Germany and covers an area of 394,000 hectares. As of 2018, it is Germany's largest nature park. History The Southern Black Forest Nat ...

Geology and earth history

The Feldsee is a tarn, around 97,500 m² in area and up to 32 metres deep. It was formed by

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

s of the last ice age. The largest tarn in the Black Forest, it is hemmed in on three sides by steep mountainsides up to 300 metres high. It is almost circular and has a diameter of between 350 and 370 metres. This area of highland at a height of , which is open to the northeast, enabled it to amass and retain the huge quantities of snow that were the cause of this armchair-shaped terrain with its steep back face, level floor and embankment of moraine at the front. The lake formed after the melting of the ice sheet behind the lines of heaped-up glacial debris.Dr. Wolfgang Fleck, Landesamt für Geologie, Rohstoffe und Bergbau
The Seebach stream, which rises between the Feldberg and

Seebuck At a height of the Seebuck is the second highest mountain the Black Forest after the Feldberg It is located in the German state of Baden-Württemberg. Geography The mountain rises in the Southern Black Forest immediately southeast of the ...

in the ''Grüble'', flows through the Feldsee, tumbling over the Feldsee Waterfall on the wall of the cirque, eventually becoming the '' Gutach'' at the far side of the

Titisee The Titisee is a lake in the southern Black Forest in Baden-Württemberg. It covers an area of and is an average of deep. It owes its formation to the Feldberg glacier, the moraines of which were formed in the Pleistocene epoch and nowadays for ...

. For several hundred thousand years this was the upper course of the ancient Danube (''Urdonau''), which flowed into the present-day

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , p ...

near

Immendingen Immendingen is a municipality in the district of Tuttlingen in Baden-Württemberg in Germany located on the Upper Danube. It is famous for the Danube Sinkhole. Geography Immendingen is located on the Upper Danube. On the municipal area are part ...

and, for the last several ten thousand years has formed a headstream of the Wutach, which flows into the

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

. Below the Feldsee, between the heaps of moraine, used to be another, smaller lake that, through the formation of

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficient ...

has silted up to become the present-day, botanically valuable bog of ''Feldseemoor''.

Nature conservation

Currently there is a general ban on bathing in the Feldsee. This is in order to protect a rare underwater fern, the spiny quillwort (''Isoetes echinospora''), that thrives in water 1–2 metres deep and only occurs in Germany in the Feldsee and

Lake Titisee The Titisee is a lake in the southern Black Forest in Baden-Württemberg. It covers an area of and is an average of deep. It owes its formation to the Feldberg glacier, the moraines of which were formed in the Pleistocene epoch and nowadays f ...

. This plant grows in lakes with cool, very clear water that are low in nutrients. Around the Feldsee is a so-called '' Bannwald''. This mixed forest is also protected and is allowed to grow naturally. It has been protected since 1937 and is the oldest nature reserve in Baden-Württemberg. The Feldsee Crags (''Feldseefelsen'') are out of bounds to climbers. The Feldberg rangers enforce these rules strictly. There are rare plants here like the alpine sow-thistle, Turk's cap lily, wolfsbane and

sundew ''Drosera'', which is commonly known as the sundews, is one of the largest genera of carnivorous plants, with at least 194 species. 2 volumes. These members of the family Droseraceae lure, capture, and digest insects using stalked mucilaginou ...

. Recently, a new species of bacteria was discovered in the lake and subsequently scientifically described. This new species, '' Polynucleobacter campilacus'' is named after the lake.Hahn MW, Koll U, Schmidt J, Huymann LR, Karbon G, Lang E (2018) ''Polynucleobacter hirudinilacicola'' sp. nov. and ''Polynucleobacter campilacus'' sp. nov., both isolated from freshwater systems,

International Journal of Systematic and Evolutionary Microbiology The ''International Journal of Systematic and Evolutionary Microbiology'' is a peer-reviewed scientific journal covering research in the field of microbial systematics that was established in 1951. Its scope covers the taxonomy, nomenclature, iden ...

68(8):2593-2601 (http://ijs.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.002880#tab2) Currently, it is not known, if this species is endemic to the lake or possesses a geographically broader distribution. ''P. campilacus'' is remarkable because of its relatively small genome size.

Access

There are no roads to the Feldsee; it can only be accessed on foot or by bicycle. The nearest car parks are 3–4 km away in Feldberg-Bärental (''Wanderparkplatz Kunzenmoos''), and on the Feldberg. The Feldsee is easily reached by bicycle from Alpersbach via the Rinken. The lake can be circumnavigated on a well-prepared path. 490 metres east of the Feldsee is the 300-year-old '' Raimartihof'' inn.

References

Literature

* Der Feldberg im Schwarzwald. Subalpine Insel im Mittelgebirge; mit Beiträgen von A. Bogenrieder, E. Liehl, E. Oberdorfer, G. Osche, W. Wimmenauer et al. (Photography: H. & K. Rasbach). – publ.: Landesanstalt für Umweltschutz Baden-Württemberg, Karlsruhe, 1982, (vergr.) * Der Schwarzwald. Beiträge zur Landeskunde; eds.: E. Liehl & W. D. Sick – 2nd edn., Verlag Konkordia, Bühl 1982, (vergr.) * August Vetter: Feldberg im Schwarzwald, Selbstverlag der Gemeinde Feldberg (Schwarzwald), 1982/1996

External links

{{wikisource, Feldsee
Legends about the Feldsee
Lakes of Baden-Württemberg Tarns of the Black Forest Breisgau-Hochschwarzwald Baden LFeldsee