Restoration of Häsener Luch

Overview

Our project site in Germany is part of the fen peatland area Häsener Luch, within the municipality of Löwenberger Land in north-east Germany. It is a representative example of the 105,000 hectares of fen peatlands under agricultural use. The Häsener Luch is part of a long-stretched depression embedded in undulating ground moraine terrain, mainly drained by the upper reaches of the artificial water body Welsengraben, which is today a 20 km-tributary of the river Havel. Of the entire fen area Häsener Luch (a complex of around 120 ha), around 53 ha are protected as a nature reserve (IUCN Management category IV) since 1953, mainly for the purpose of preserving then already rare fen-typical flora like orchids or the carnivorous Common Butterwort.  
 
The project site of around 60 ha consists mainly of the nature reserve’s territory. Its core area of 19 ha with many of the water bodies from former cutting is owned by the regional NABU Gransee and is mainly not used anymore.  

©VolkerGehrmanns

Background

The history of the Häsener Luch is also a history of drainage. A drainage system was built as far back as the 18 th century, when a number of systematic drainage projects for agriculture and forestry were launched in Prussia. Significant peat extraction took place until the first half of the 20th century, which in combination with drainage formed a variety of habitats with ponds, dams, bushland and herbaceous vegetation. Drainage intensification from the 1960s on within the frame of increasing agricultural demands of the GDR resulted in permanently low water tables with sub-surface levels of often less than 80 cm in summer, a condition which persists into the present. Today there are around 1800 m of active ditches surrounding the NABU owned site, and another 1800 m of active ditches in the rest of the 60 ha project site. The central drainage ditch is the Welsengraben.  
 
A survey in 2022 still found peat layers of up to 2.80 m (average 0.9 m), indicating a massive loss of peat in the past 50 years and consequently high greenhouse gas emissions. The need for action for restoration in the Häsener Luch is enormous. 

Objectives

The central aim of the project therefore is to achieve a partial rewetting of the nature reserve and with this: 

• an increase of the water retention capacity 
• a significant reduction of the greenhouse gas emissions 
• a re-establishment of fen-typical vegetation, which in the long run can potentially induce peat formation and turn the carbon source back into a carbon sink 
• help bring back endangered flora and fauna 
• accompany and verify all measures by a detailed monitoring system covering the development of vegetation, water levels and greenhouse gas emissions 
• conduct a feasibility study on paludiculture for these areas and the surrounding intensively used fen grasslands