The Harz (), also called the Harz Mountains, is a highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The name Harz derives from the Middle High German word Hardt or Hart (hill forest). The name Hercynia derives from a Celtic name and could refer to other mountain forests, but has also been applied to the geology of the Harz. The Brocken is the highest summit in the Harz with an elevation of above sea level. The Wurmberg () is the highest peak located entirely within the state of Lower Saxony.
Geography
Location and extent
The Harz has a length of , stretching from the town of Seesen in the northwest to Eisleben in the east, and a width of . It occupies an area of , and is divided into the Upper Harz (Oberharz) in the northwest, which is up to 800 m high, apart from the 1,100 m high Brocken massif, and the Lower Harz (Unterharz) in the east which is up to around 400 m high and whose plateaus are capable of supporting arable farming.
The following districts (Kreise) fall wholly or partly within the Harz: Goslar and Göttingen in the west, Harz and Mansfeld-Südharz in the north and east, and Nordhausen in the south. The districts of the Upper Harz are Goslar and Göttingen (both in Lower Saxony), whilst the Lower Harz is on the territory of Harz and Mansfeld-Südharz districts (both in Saxony-Anhalt). The Upper Harz is generally higher and features fir forests, whilst the Lower Harz gradually descends into the surrounding area and has deciduous forests interspersed with meadows.
The dividing line between Upper and Lower Harz follows approximately a line from Ilsenburg to Bad Lauterberg, which roughly separates the catchment areas for the Weser (Upper Harz) and Elbe (Lower Harz). Only on the southeastern perimeter of the Upper Harz, which is also called the High Harz (Hochharz) (Goslar, Göttingen and Harz districts), does the mountain range exceed on the Brocken massif. Its highest peak is the Brocken (1,141 m), its subsidiary peaks are the Heinrichshöhe (1,044 m) to the southeast and the Königsberg (1,023 m) to the southwest. Other prominent hills in the Harz are the Acker-Bruchberg ridge (927 m), the Achtermannshöhe (925 m) and the Wurmberg (971 m) near Braunlage. In the far east, the mountains merge into the East Harz foothills (Harz district, Saxony-Anhalt), which are dominated by the Selke Valley. Part of the south Harz lies in the Thuringian district of Nordhausen.
The Harz National Park is located in the Harz; the protected area covers the Brocken and surrounding wilderness area. Approximately 600,000 people live in towns and villages of the Harz Mountains.
Rivers and lakes
Because of the heavy rainfall in the region the rivers of the Harz Mountains were dammed from an early date. Examples of such masonry dams are the two largest: the Oker Dam and the Rappbode Dam. The clear, cool water of the mountain streams was also dammed by early mountain folk to form the various mountain ponds of the Upper Harz waterways, such as the Oderteich.
The 17 dams in the Harz block a total of twelve rivers. Because the Harz is one of the regions of Germany that experiences the most rainfall, its water power was used from early times. Today the dams are primarily used to generate electricity, to provide drinking water, to prevent flooding and to supply water in times of scarcity. Modern dam-building began in the Harz with the construction of the Söse Valley Dam, which was built between 1928 and 1931. The dams of the Upper Harz lakes are some of the oldest dams in Germany that are still in operation.
→ See List of dams in the Harz
The largest rivers in the Harz are the Innerste, the Oker and the Bode in the north; the Wipper in the east; and the Oder in the south. The Innerste merges into the Leine and its tributaries are the Nette and the Grane. The rivers Radau, Ecker and Ilse all discharge into the Oker. The Hassel, the Selke and the Holtemme (whose main tributary is the Zillierbach) flow into the Bode. The Wipper is fed by the Eine. The Rhume is joined by the Söse and the Oder; the latter being fed by the Sieber. The Zorge, the Wieda and the Uffe all flow into the Helme.
Hills → See List of hills in the Harz → See List of rock formations (crags, tors, etc.) in the Harz
Climate Climatically a hill range has lower temperatures and higher levels of precipitation than the surrounding land. The Harz is characterised by regular precipitation throughout the year. Exposed to westerly winds from the Atlantic, heavy with rain, the windward side of the mountains has up to 1,600 mm of rain annually (West Harz, Upper Harz, High Harz); in contrast, the leeward side only receives an average of 600 mm of precipitation per annum (East Harz, Lower Harz, Eastern Harz foothills).
Geology and pedology Origins
The Harz is the most geologically diverse of the German Mittelgebirge, although it is overwhelmingly dominated by base-poor rocks. The most common rocks lying on the surface are argillaceous shales, slaty (geschieferte) greywackes and granite intrusions in the shape of two large igneous rock masses or plutons. The Gießen-Harz surface layer of the Rhenohercynian zone, which is widespread in the Harz, consists mainly of flysch. Well-known and economically important are the limestone deposits around Elbingerode and the Gabbro of Bad Harzburg. The landscapes of the Harz are characterised by steep mountain ridges, stone runs, relatively flat plateaus with many raised bogs and long, narrow V-shaped valleys, of which the Bode Gorge, the Oker and Selke valleys are the best known. A representative cross-section of all the Harz rocks is displayed on the Jordanshöhe near Sankt Andreasberg near the car park (see photo).
The formation and geological folding of the Harz hills began during a prominent phase of the Palaeozoic era, in the course of the Hercynian mountain building of the Carboniferous period, about 350 to 250 million years ago. At that time in the history of the Earth, numerous high mountains appeared in Western Europe, including the Fichtel Mountains and Rhenish Massif. They were, however, heavily eroded due to their height (up to 4 km) and were later covered over by Mesozoic rocks. From the Early Cretaceous and into Late Cretaceous times the Harz was uplifted in a single block by tectonic movements and, particularly during the Tertiary period, the younger overlying strata were eroded and the underlying base rock left standing as low mountains. The most important uplift movements were during the sub-Hercynian phase (83 mya), when the northern edge was steeply tilted. This formed a fault zone on the northern border of the Harz (the Northern Harz Boundary Fault or Harznordrandverwerfung).
The Harz is a fault-block range, that rises abruptly from the surrounding lowlands in the west and northeast and gradually dips towards the south. It is dissected by numerous deep valleys. North of the hills lie the Cretaceous layers of the sub-Hercynian depression in the rolling hills of the Harz Foreland; south of the Harz, Permian sediments lie flat on southwest-dipping Palaeozoic beds.
As a result of the northern fault zone and the vertical or, sometimes even overfolded, geological strata, the geology of the Harz sometimes changes frequently within a relatively small area of just a few square kilometres. As a consequence of this it is also referred to as the "Classic Geological Square Mile" (Klassischen Quadratmeile der Geologie).
There is a room devoted to geology in the Harz Museum in Wernigerode.
Nature
Flora The vegetation of the Harz mountains is divided into six altitudinal zones: Subalpine zone: Brocken summit, over Altimontane zone: highest areas (except the Brocken summit) between 850 and Mean montane zone: higher areas between 750 and Montane zone: medium height areas between 525 and Submontane zone: lower areas between 300 and Colin zone: areas around the edge of the Harz between 250 and
Types of woods
Beech woods From the edge of the Harz to 700 m above sea level beech woods dominate, especially the wood-rush beech woods on locations poorly supplied with nutrients where the common beech (Fagus sylvatica) is often the only tree species. In lower, drier locations the English oak (Quercus robur) and sessile oak (Quercus petraea) occur as well. sycamore trees (Acer pseudoplatanus) may be found growing in wetter places. During times of decay and rejuvenation when there is plenty of light, light-dependent pioneers such as rowan (Sorbus aucuparia), silver birch (Betula pendula) and pussy willow (Salix caprea) play a role. Melic grass beech woods are found in the few places where there is an abundance of nutrients and bases, e. g. over dolerite and gneiss formations, and they have a vegetation layer rich in variety and luxuriant growth. Here, too, the common beech dominates, mixed, for example, with sycamore, ash (Fraxinus excelsior), hornbeam (Carpinus betulus) and Scots elm (Ulmus glabra). As a result of the increasingly continental climate on the eastern edge of the Harz, the common beech gives way to mixed forests of sessile oak.
Mixed woods At intermediate heights of between 700 and 800 m above sea level, mixed woods of spruce (Picea abies) and common beech would predominantly be found under natural conditions. However, apart from a few remnants, these were supplanted a long time ago by spruce stands as a result of deliberate forest management. Sycamore trees are also found in these woods.
Spruce woods Spruce woods thrive in the highest locations from about 800 m to the tree line at around 1,000 m above sea level. These woods are also home to some deciduous trees such as rowan, silver and downy birches (Betula pendula and Betula pubescens) and willows (Salix spec.). Conditions of high humidity foster an environment rich in mosses and lichens. In spite of the near-natural habitat there are only a few, indigenous, genetically adapted (autochthonous) spruce trees. Wood-reed spruce woods dominate. A well developed ground vegetation thrives on their moderately rocky and fresh, but certainly not wet, soils, characterised in appearance especially by grasses such as shaggy wood-reed (Calamagrostis villosa) and wavy hair-grass (Avenella flexuosa). The soils in the higher regions are, as in most of the Harz, comparatively poor in nutrients and bases, so that only a few herbaceous plants occur here, such as heath bedstraw (Galium saxatile). For that reason it is more the ferns, mosses, lichens and fungi that, in addition to spruce trees, characterise these woods. Boulders and stone runs occur in the areas of weather-resistant rock in the high (alti-)montane and montane zones – these are extreme habitats for vegetation. Due to the lack of soil material, only weak, straggly, very open spruce woods thrive here. They have an especially high variety of trees and allow more room of light-loving species such as silver birch, rowan, sycamore, willow and dwarf bushes such as the blueberry (Vaccinium myrtillus). Mosses and ferns are also common here. One unusual species is the Carpathian birch (Betula pubescens subsp. carpatica). Bog-spruce woods are found around the raised bogs on marshy and boggy soils. In these sorts of places spruce woods can, in exceptional cases, also form the natural woodland in lower down the mountains. These wet, moorland woods have a high proportion of peat mosses (Sphagnum spec.). The ground vegetation may also have a rich proliferation of low bushes such as cowberry (Vaccinium vitis-idaea). Clumps of purple moor grass (Molinia caerulea) are also typical of this type of woodland habitat. The characteristic species of fungi in natural spruce woods are Phellinus viticola and prunes and custard (Tricholomopsis decora).