NABU project for moor protection at the Theikenmeer in Lower Saxony
The Theikenmeer is one of the oldest protected areas in Germany. Dramatic changes put the moor in danger, drained areas overgrown with birch trees. NABU now wants to revive the bog, among other things with the help of bog sheep.
Theikenmeer from the air – Photo: A.Schuring
A male moor frog in mating mood – Photo: A.Schuring
Adders sunbathe in dry and warm places at the Theikenmeer – Photo: A.Schuring
In the northeast of the Emsland district, about three kilometers west of the town of Werlte, lies the Theikenmeer nature reserve. The body of water, the eponymous Theikenmeer, is the remnant of a so-called Laggsee, which formed from the run-off water of the former raised bog between the bog body and the adjacent edge of the Geest.
About the NABU project
NABU’s long-term goal is to rewet large areas of the Theikenmeer nature reserve. The aim is to stop peat decomposition and promote the revitalization of the raised bog. With the project "Moor protection at the Theikenmeer" – based on the past successes – decisive steps for the further development of the high moor protection are to be implemented.
- Development of a renaturation concept
In the first half of 2009, an area-specific renaturation concept will be developed, which will determine the priorities for the purchase of land and the subsequent rewetting measures.
- Acquisition of land from private ownership
According to the priorities defined in the renaturation concept, the areas still in private ownership are being purchased. The purchase price depends on the type of use. In total, about 100 hectares can still be acquired in and around the protected area.
- Preparation of wooded areas
In order to optimize the habitat for light-loving animals and plants on the areas to be rewetted, they are cleared of woody vegetation prior to rewetting.
- Carrying out the hydraulic engineering work
Following the acquisition of the land, the rewetting measures are to be carried out in sections (for an area of 10 to 20 hectares each). A water law permit must be obtained for the damming of previous drainage ditches. The cost per section – depending on the required construction measures – is estimated at about 20.000 euros calculated.
The Theikenmeer nature reserve
Theikenmeer – Photo: A.Schuring
The conditions for the moor at the Theikenmeer were created in the last ice age. At that time, in the area of the Theiken Sea, the meltwater from the melting glaciers collected and a lake was formed. Fine soil and humus was washed into these lakes, causing them to silt up over time. A fen has now developed on the site. The plants growing there were fed with nutrients and moisture from the groundwater. Because the surface of the marsh was constantly wet, dead plant parts could not be decomposed by microorganisms: The water (simply) lacked oxygen, without which even microorganisms cannot live. The dead plant matter accumulated year after year, causing the bog surface to gradually grow in height. Peat formed, which grew out of the groundwater area. The higher the bog grew, the less nutrients and water the plants could get from the groundwater area.
From then on, only a few highly specialized plants were able to survive on the marshland as it curved upwards. They have to make do with the nutrients and moisture the rain provides them. Many raised bog plants have developed fascinating survival strategies: the sundew, for example, catches small insects with the help of sticky drops and thus provides itself with the vital nutrients it needs.
The nature reserve (NSG) was already designated in 1936. It is thus one of the oldest protected areas in Lower Saxony. In 1983 the nature reserve was extended to its present size of 250 hectares by the Dosenmoor and in 1993 by the NSG Moorwiesen am Theikenmeer, which directly adjoins it to the north.
The moor and the Theikenmeer underwent dramatic changes despite the early protection status. Drainage measures caused many areas to dry out and become overgrown with birch trees. The water surface of the once 26-hectare sea became smaller and smaller and even disappeared completely for a short time in 1977. Since that time, the Lower Saxony NABU group Werlte/Sogel has been active there together with the man of the first hour Dr. Andreas Schuring active.
Between 1978 and 1981, damming measures made it possible to restore the sea to a water surface area of about 20 hectares. After the worst dangers for the Theikenmeer had been averted, a plan to save the high moor habitat Theikenmeer was developed which has been gradually advanced over the last 20 years. Today, NABU owns almost 40 hectares of land at the Theikenmeer and manages another ten hectares owned by the Frankfurt Zoological Society (ZGF). Part of the remaining area in the protected area is now owned by the public sector. Of this also about 50 hectares are cared for by the NABU over appropriate use agreements.
Unique habitat for strictly protected species
Many bog-typical plants and animals can only be found in this special habitat at the Theikenmeer They all have in common that they are ideally adapted to the extreme conditions of a bog (humidity, strong direct radiation, low nutrients). Too much shading by growing trees and heavy nutrient inputs would quickly lead to their being displaced by other, less specialized species.
Since 1998, NABU has been using machines and a herd of white-horned moorland sheep on the areas where an excessively low water level promotes the growth of woody plants and the degradation of the peat to ensure that regrowing birch trees and moor grass are kept permanently small. A large adder population has found a home here, as have the strictly protected bird species marsh harrier, short-eared owl, red-backed shrike, stonechat and nightjar. Cotton grass, sundew and orchid also thrive in the Theikenmeer.