Bavarian Forest
National Park

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Mires

Raised bog (Photo:Alice Alteneder)

Peatland forests and open bogs are among the ecologically most valuable habitats in the Bohemian Forest. The high, precipitation rich plateaus of the Šumava National Park are at the centre of the mire distribution across the mountain range. In basins with little run off and in locations above 1,000m ideal conditions exist for the formation of bogs.

On the Bavarian side only the waterlogged valleys and the ridges are home to large areas of peat bog. Particularly impressive is the valley mire complex of Großer Filz and Klosterfilz between Riedlhütte and St. Oswald. In the higher areas Zwieseler Filz and Latschenfilz can be counted among the highlights.

The peatland forests share the focus of their location – waterlogged valleys and precipitation rich plateaus - with open mire areas. None of the various types of mire can be regarded as particularly isolated. There is always a tight interlocking with other forms of mire. The transitions from peatland forests to open mire areas are also fluid, so that there are always complexes composed of differing mire habitats.

Peatland forests

On fens and transitional mires in cold, waterlogged hollows spruce peatland forests find life difficult. The peaty soils are wet, acidic and lacking in nutrients. Apart from the spruce only the occasional fir, rowan or mire birch manages to assert itself. The picture is varied. Standard spruce trees on weakly developed peat belong here just as dwarf trees on thick peat moss beds. Only those that have far reaching root plates such as the spruce have a chance on this variable soil. The price paid for this courage is however a limited life expectancy. Storms bring whole areas of forest to the ground here more often than they do in other habitats. However, new generations of spruce sprout up and grow again from among the felled and decaying trees.

Mountain pine peat forests populate the even more waterlogged, acidic and nutrient poor locations. In the national park they cover mostly the curved, hourglass-like raised bogs. Only in the centre of the mires do the most waterlogged areas remain free of trees, thereby creating open raised bogs. The mountain pine is very varied in its appearance and has different subspecies. As the “Spirke", a ‘traditional’ tree reaching up to 10 metres in height, it populates the raised bogs of the valleys. In the higher areas however there are just the three to four metre shrub-like “Latsche".

Raised and transitional bogs

In a landscape totally dominated by forest, there are areas that maybe surrounded, but which defend their ground against the aggressive dominance of the trees; by nature there is something special about them. This includes parts of the raised and transitional bogs, which manage, at least occasionally, to prevent the spruce and mountain pine forests from reaching the centre of the mire.

Living raised bogs are characterised by an untainted, integral reservoir of water fed only by rain water. The chemical environment is marked by high levels of acidity and low levels of nutrients and oxygen. Typical raised bog biotopes such as the hourglass-like arching of the peat body, the external edges, little hill-like elevations and bog hollows, pools and bog ponds are all present. Individual deformed and aged dwarf trees, which have cheekily sown themselves in to the bog, struggle to survive, but otherwise the mire surfaces are forest free.

Raised bogs, in which the soil moisture regime has been enormously influenced by drainage ditches or peat cutting, are deteriorating in increasing numbers. Here there is inevitably the task of restoring the mire. Such mire restoration methods have been carried out in the national park for many years. The aim is to restore the integral bodies of water through blocking the drainage ditches.

Transitional and floating mires can be found on the edges of raised bogs, the banks and floating mats of drying lakes, the spring mires of the high areas and the in former wet meadows that are being transformed through paludification. Correspondingly wide is the variety of plant communities, which range from plants thriving on transitional ground such as sedge through to different peat moss species, from wool grass to bog hollow species.