PROJECT DESCRIPTION
BACKGROUND
The Hohlohmoor is part of a raised bog landscape formed on the Kaltenbronn, with an unusually large area of 3.6 km2 for low mountain ranges - by far the largest in the entire Black Forest. Equally extraordinary are the quantities of peat stored in this moorland: approximately 9 million cubic metres. Peat deposits reach an average thickness of between 2.5 and 3.5 m; however, in the Hohlohmoor they reach maximum 5.5 m and even up to around 8 m in the neighbouring Wildseemoor.
These dimensions alone make the complex unparalleled among the slope rain-fed bogs in the low mountain range of the continental region. Additionally, it is characterised by the occurrence of several bog pools, of which the large ones are among the largest bog eyes in Central Europe, as well as extensive stands of bog pine and spruce bog forest. These characteristics elevate the Kaltenbronn bog complex to nationally representative importance and make it a particularly significant component of the Natura 2000 network of protected areas.
The peatland complex at Kaltenbronn and its habitats are at risk due to a lack of water supplies. The threat is a result of the historically extensive and dense drainage systems, and more recently, the increased frequency of long droughts in summer due to climate change.
In a changing climatic environment, peat deposits as water and carbon reservoirs, as well as the habitats as carriers of biodiversity, are degenerating. The following can be observed:
A loss of around 95% of the open raised bog areas in the last 100 years;
An imminent complete loss of the remaining stocks of the priority habitat type;
A progressive impoverishment of the species inventory of the peatland forest as a result of a decline in specialists of the flora and fauna of wet sites;
Progressive peat cutting and associated loss of peatland waters, as well as water (intermediate) reservoirs and water donors for the surrounding peatland habitats;
A progressive reduction in habitat capacity for light-demanding species of structurally rich woodland/ open land complexes (e.g., capercaillie (Tetrao urogallus), Common European adder (Vipera berus));
Progressive degeneration and the loss of small-scale habitats that are functionally linked to the above-mentioned priority habitat types.
OBJECTIVES
The project focuses primarily on the development of a more favourable conservation status of several priority habitat types in Hohlohmoor. These habitat types include Moorland forest, with decreasing tendency moor pines and increasing spruces, as well as near-natural Highland bog.
The main focus of the project is to ensure water supply, which is crucial for the preservation and growth of peatlands, their bogs, and the various species that inhabit them. The goal is to enhance their ability to withstand large-scale climatic droughts, which are becoming more common due to rapid and fundamental changes in the climate. This is particularly feasible in the northern Black Forest’s peak conditions, which benefit from relatively high total precipitation at nearly 1,000 meters above sea level.
In addition, the conservation status of other, small-scale non-priority habitats in the functional complex should be improved and their area increased, meaning:
Degraded raised bog (7120)
Transition mires and quaking bogs (7140)
Depressions on peat substrates (7150)
Natural dystrophic lakes and ponds (3160: approx. 0.9 ha):
2 larger bog lakes (Großer and Kleiner Hohlohsee)
1 smaller bog pond (Breitlohsee)
The moorland landscape at Kaltenbronn is home to numerous rare and threatened species that will benefit from the promotion of the above-mentioned habitats, including:
Species of the Birds Directive: Capercaillie (Tetrao urogallus)
Other priority species according to endangerment situation and protection status within Germany and Baden-Württemberg:
Animals: Common European adder (Vipera berus), dragonfly species Coenagrion hastulatum and ants Formica picea.
Plants: Scheuchzeria palustris, Carex pauciflora, Sphagnum balticum.
The entire inventory of bog habitats, consisting of "characteristic species" according to the Habitats Directive.
RESULTS
The project aims to reach the following results:
Restoration of a moor-typical water balance by taking the following actions:
Raising the peatland water level to areas close to the river all year round;
Retention, distribution and improved (intermediate) storage of water;
Generation of areal seepage water flows in the peat formation horizon;
Raising the water level of the Großer Hohlohsee by approx. 40 cm and increasing its water storage volume;
Restoration of drained bog pools and swales.
Thanks to these actions, the expected results will be:
Improvement of the condition and thus preservation of the endangered priority Natura 2000 habitat types Bog woodland (code *91D0) and Active raised bogs (code *7110), as well as other habitat types with smaller functional connectivity.
Increase the proportion of semi-open and open stands, especially of the priority habitat type Active raised bogs (*7110).
Restoration of priority habitat type Active raised bogs (*7110) from the stock of the habitat type Degraded raised bogs still capable of natural regeneration (7120).
Promotion and thus conservation of the characteristic species inventory associated with near-natural peatlands and open peatland habitats, including numerous highly endangered or critically endangered species.
Promotion and thus conservation of further characteristic endangered species linked to structurally rich woodland/open land complexes, including the capercaillie (Tetrao urogallus).
Reactivation and preservation of the mighty peat bodies, as well as important carbon reservoirs and archives of landscape history.
