The Hainich-Dün region is located in northwestern Thuringia in the middle of Germany. It includes the “Hainich” forest region in the south and the “Dün” region in the north, connected by the “Obere Eichsfeld”.
Hainich, with its 16.000 ha, is one of the largest closed forest areas in Germany that is dominated by broad-leaved trees. Hainich National Park, founded in 1997, is located at the southern edge of this region and covers an area of 7,600 ha (fig. 1). It is characterized by unmanaged pure or mixed beech forests (Fagus sylvatica, with Fraxinus exselsior, Acer pseudoplatanus and others). In the central part of the national park there is an old-growth forest of 261 ha, which is unique for Germany in terms of its age, structure and extent. On former military training sites in the national park, several successional stages from grassland to forests can be observed. The grassland is extensively grazed by sheep in order to naturally preserve the open land it with the existing flora and fauna. In 2011, Hainich National Park was inscribed in the UNESCO World Heritage list.
|Annual precipitation sum||500-800 mm|
|Elevation||258-550 m a.s.l.; highest point: “Alter Berg” in 494 m a.s.l.|
|Typical plant species||Wood anemone, large stands of wild garlic, mercury, spring snowflake|
|Dominant forest type||European (mixed) beech forests|
|Characteristic management types||Selection-cutting forests (so-called “Plenterwald”) organised in forest cooperatives; extensively managed grasslands grazed by sheep forming juniper heath|
|Specific information||With 16,000 ha one of the largest continuous deciduous forest areas in Germany. Forest sites of the national park since 1935 unmanaged and out of use.|
The national park Hainich
In the region Hainich-Dün a broad spectrum of differently used forests occur, including selection-cutting forests, age-class forests, so-called “Bauernwald” which was used by farmers and particularly diverse in tree composition, and forest island of different sizes. The research plots of the Hainich-Dün exploratory are distributed among forest areas of different land use intensity to cover the different regional management types. As dominating tree species beech is characteristic for the Hainich, often mixed with ash, sycamore, field maple, wych elm, oak and lime tree. In spring, the forest floors are covered extensively by early bloomers, such as wood anemones, wild garlic, mercury, or spring snowflakes. In old-growth forests, the wildcat and various deadwood beetle species and fungi are characteristic for the Hainich region (fig. 2).
The forest areas of the Hainich are surrounded by small settlements, arable land, meadows, pastures and limestone grasslands (fig. 3). In the Dün and Eichsfeld region grasslands and agricultural land occur with variable management intensity. Compared with the forest region, the extent of grasslands is relatively small, because they are under a pressure of land-use change. Extensively managed grasslands were formerly grazed by sheep (fig. 4), and these are under pressure of afforestations, while the more fertile intensive grasslands are under pressure to be converted to arable land. Towards the east the Hainch-Dün adjoins the agricultural land of the Thuringian Basin which belongs to the most fertile soils in Germany.
In the exploratory Hainich-Dün limestone (upper shell-limestone) and Loess constantly alternate (fig. 5). Therefore, silty, loamy and clayey soil textures dominate. Because a varying quantity of loess is deposited, the soil depth is varies considerably. While the limy, weathering clays often consist of carbonate, the pH value is between 5 and 6. In loess soils, strong soil leaching causes the development of clayey stagnant horizons and stagnant moisture. Dominating soil types are lessivé and pseudogley. On shell-limestone along hill sides rendzina occurs. Otherwise brown earth is frequent (fig. 6).
With the help of inventories, 100 so-called experimental plots (EP) were selected from 1000 plots per exploratory (50 in forest and 50 in grassland) and permanently marked. These 100 plots cover the largest possible spectrum of land use intensities in the region, but differ as little as possible in other variables such as soil type. In the forest, these experimental plots have a size of 100 x 100 m, in the grassland of 50 x 50 m. Each of the plots is equipped with a climate measuring station within a 3 x 3 m fenced area.
Depending on the effort and costs involved, experiments can be conducted not only on all 100 EPs, but also on subsets of 50 (so-called MIPs, plots of medium research intensity) or 18 (so-called VIPs, plots of high research intensity) study plots (For more information see research design).
In the Hainich exploratory, 3 additional VIPs were selected which cover a region-specific land use type: the selection-cutting forests („Plenterwald“).
The Hainich is one of the largest continuous deciduous forest areas in Germany on fertile substrates dominated by limestone and loess. As dominating tree species beech is characteristic for the Hainich, often mixed with ash, sycamore, field maple, wych elm, oak and lime tree.
The forest experimental plots are located in unmanaged natural beech forests (National Park Hainich), in selection-cutting beech forests (so-called „Plenterwälder“ in Langula and Keula), in managed age-class forests dominated by beech (Westerwald, Geney, Sollstedt, Zehnsberg, Behringen, Mühlhausen), and dominated by spruce (Mühlhausen, Anrode).
The forest experimental plots (n = 50) cover the following land use types:
- Spruce – Age-class forest (AKL) – young timber
- Spruce – AKL – old timber
- Beech – thicket
- Beech – AKL – young timber
- Beech – AKL – old timber
- Beech – AKL – multiple layered
- Beech-mixed forest (< 70 % beech) thicket
- Beech-mixed forest (< 70 % beech) young timber
- Beech-mixed forest (< 70 % beech) AKL old timber
- Beech-selection-cutting forest
- Beech – unmanaged – old timber
Compared to the forest areas, the grassland areas in the Hainich-Dün exploratory are of smaller size and are characterized by scattered positions between small settlements and arable lands.
The open sites with small water bodies are habitat, e.g. for whinchat, barred warbler, red-backed shrike and wryneck, for crested newt and yellow-bellied toad.
Unfertilized sites represent extensive grassland, predominantly grazed by sheep. Most of these unfertilized pastures are located on former military training grounds or on soils that are of shallow substrates (e.g. locations of dry grassland communities). Locally, juniper heaths have developed under this land use type, being located for example close to Craula and Oberdorla.
Another characteristic land use type of the Hainich-Dün region are fertilized mown pastures, mostly grazed by suckler cows and calves, or by young cattle. Very intensively managed meadows of high mowing frequency or high fertilization rates (liquid manure) rarely occur in the Hainich-Dün region, but are then used for dairy farming.
Most farms tend to cultivate their meadows extensively with one or two mowing events during the year and low or no fertilization.
The grassland areas of the Hainich-Dün exploratory are thus fertilized or unfertilized pastures, meadows or mown pastures. They are towed, groomed or mulched in autumn or spring.
The grassland experimental plots (n = 50) cover the following land use types:
- Meadows – fertilized with 1-2 mowing events
- Mown pastures – fertilized and grazed by sheep or cattle
- Pastures – unfertilized and grazed by cattle
- Pastures – dry grassland communities grazed by sheep
Local Management Team Hainich-Dün
Technical University of Munich
Chair for Terrestrial Ecology
Field station Hainich-Dün exploratory
Am Burghof 3
Phone: +49 (0) 36022 159 843