Carbon Sink or Carbon Source? A Guided Tour through a Peat Landscape in Transformation
The Wietingsmoor in Northern Germany hosts surprisingly many unique landscape features and functions. One month of local fieldwork allowed me to better understand the complex peatland reality. Peatlands are important reservoirs of carbon stocks, biodiversity, cultural heritage, and endangered landraces. And they are ground to innovative projects and thriving ideas to path ways to a sustainable future.
Around the world, peatlands are being drained for the purposes of peat harvesting or gaining land for agricultural production, leading to the highly concerning degradation of peatlands on a global scale.
Besides biodiversity loss, one of the most recent concerns regarding peatland destruction is the emission of carbon dioxide (CO2). This occurs for example in drained peatlands, where the accumulated biomass (in form of peat) comes into contact with oxygen, which promotes its decomposition and thus the deliberation of the stored CO2 into the atmosphere.
Emissions due to the drainage and degradation of peatlands measure up to 5–6% of all global greenhouse gas emissions worldwide, which doubles the total emissions of a highly industrialized and energy-intensive country such as Germany. Until now, it is estimated that most of the global peatlands (80%) remain intact. However,
900,000km2 of the peatlands are already degraded, and the rate of peat accumulation decreases. In other words: Degraded peatlands turn from a carbon sink to a carbon source.
Pathways to sustainable peatlands
The most effective strategy to avoid these emissions is to stop peatland degradation by protecting near-natural peatlands. Another one is the restoration and rewetting of degraded peatlands. It may, however, take several decades until rewetted peatlands accumulate biomass in form of peat and become carbon sinks again.
Apart from understanding physical and ecological parameters, sustainable transformation relies on paradigm shifts and changes in peoples’ mindsets to deal with new challenges. When it comes to peatlands, the success to reactivate and conserve their carbon storage potential depends foremost on the active participation of a diverse group of stakeholders who live and work at the sites. A deeper understanding of local perceptions regarding the ecosystem values that peatlands provide is key to co-designing a sustainable peatland future. Such a vision would consider multiple stakeholder perspectives, political pressures, as well as innovative ideas to create alternative management options and income opportunities for diverse interest groups.
I would like to take you on a small tour through our project area — visiting its characteristic places, and the people involved in the sustainable transformation of degraded peatlands.
The Wietingsmoor under transformation
Our project site is the Wietingsmoor in Northern Germany, which forms part of the Diepholz Mire Basin (Diepholzer Moorniederung), a large peatland area with a total surface of about 105,000 ha in the German federal state of Lower Saxony. The Wietingsmoor is a highly diverse peat landscape, of which more than 5,000 hectares are raised bogs, forming one of the largest raised bog areas in Germany. The Wietingsmoor is characterized by a long history of drainage for agricultural production and peat extraction. At the same time, it is an important habitat for rare bird species and unique flora and fauna.
First conservation efforts were made more than 50 years ago. Nowadays, peat landscapes have gained a lot of political interest as part of climate protection strategies: In March 2022, the German government presented an Action Plan For Nature-Based Climate Protection with a budget of 4 billion euros, the highest financial support of this kind ever provided nationally. One main pillar of this program is the rewetting of peatlands.
The Middle and Southern part of the Wietingsmoor, which we decided to focus on, include restored and rewetted peatland sites, but also sites with intensive agricultural production, where peatland restoration is hindered: Here, some local landowners are not willing to sell or exchange their agricultural land for conservation and restoration purposes.
Restoration of peatland through rewetting
Let’s start our “People and Peatlands” tour with the rewetting and restoration process of degraded peatlands: The first steps of this long process are to watch out for available larger connected areas, and to examine the specific hydrological and soil conditions in order to work out further management options. Rewetting peatlands at a site will also affect the surrounding farmlands; decisions thus have to be taken at the watershed level. As the implementation of such a project requires a rather large area, the process requires close collaboration with landowners and other interest groups to build consent regarding the selection of suitable sites for rewetting. One of the responsible institutions in this regard is the land consolidation authority (“Flurbereinigungsbehörde”). It has to negotiate with farmers who are willing to sell their land, or to exchange their properties with other farmlands. Both options require a transparent and detailed planning process as well as trust-building.
Once suitable sites are identified, the more mechanistic process begins: Organic matter is moved away and used to build small walls around the peat basin. Small agricultural ditches to drain the land (called “Grüppen” in Low German) need to be blocked so rainwater can accumulate in the peat basin.
To protect the site from the invasion of plants lowering the water level through transpiration, upcoming vegetation — such as birch (Betula spp.) or pine trees (Pinus spp.) — has to be removed continuously. This also favors the typical peat vegetation, such as peat moss (Sphagnum spp.), sundew (Drosera spp.), or bog rosemary (Andromeda polifolia). Sometimes it is required to introduce typical peatland plants such as Sphagnum moss, which are able to absorb large amounts of water and change the acidity of the environment, thus creating optimal conditions for the accumulation of dead plant materials — in form of peat.
Once the rewetting process is finalized, different management options exist. One of them is paludiculture, the agricultural production on wet peatlands. Paludiculture is also practiced in the Wietingsmoor.
So let´s continue with our peatland tour and learn about innovative paludiculture projects.
Paludiculture projects in the Wietingsmoor
Growing peat moss on rewetted peatland
Since 2019, Dr. Jens-Uwe Holthuis is leading a one-hectare experimentation site in the municipality of Barver close to Diepholz, to cultivate peat moss. Peat moss species can be used as a sustainable substitute for peat, as a growth medium for orchids, or for indoor agricultural production. They are also sold as Christmas decoration or to terrarium owners.
Next to the peat moss farm, there is another small experimentation site to cultivate sundew (Drosera spp.) which is valued for its medicinal purposes:
Don’t be surprised by grazing water buffalos
Close to the Sphagnum farm, water buffalos are roaming through the peatland. Most people may know these animals from zoological gardens or wildlife documentaries. In Europe, wild water buffalo populations became extinct about 100,000 years ago. Around 5,000 years ago, water buffalos were domesticated in India and China and then reintroduced to Europe around 700 AD. Most of these European domesticated water buffalos (Bubalus bubalis) can be found in the Balkans and Italy. We all know the famous Italian mozzarella cheese that is made of water buffalo milk. Organically produced water buffalo meat is much demanded; people even have to preorder to get to enjoy its taste. According to some cuisine experts, water buffalo meat has an excellent mild and aromatic taste and is valued for its low fat content.
Seven years ago, the Stiftung Naturschutz und Landespflegebetrieb Freistatt started to introduce water buffalos to the Wietingsmoor for reasons of landscape preservation. Since then, the herd is constantly growing. Water buffalos are very robust animals and well-adapted to wet conditions: They resist heat and tropical temperatures, but also the harsh climate of the middle-European winter months.
Not to forget the Moorschnucke and its shepherds and guardians
Another peatland “resident” is the Moorschnucke. Local people are very proud of these animals, which originate in the Diepholz Mire Basin. The Moorschnucke is a small and light-weighted robust sheep landrace that is optimally adapted to peatlands. It is probably the result of selective breeding of a hornless Heidschnucke. Both Moorschnucke and Heidschnucke are listed as endangered landraces in Germany.
Moorschnucken are peatland preservation specialists: They help to avoid the invasion of birch species and grasses and prevent the bushing of bogs and mires. Local shepherds are also experimenting with crossings of the Moorschnucke with the Charmoise sheep race, in order to increase the animals’ meat production potential.
The sheep herds you see in the Wietingsmoor are usually accompanied by Great Pyrenees or the “Harzer Fuchs“, livestock guardian and herding dogs that keep the herds together and protect them against wolf attacks. The Harzer Fuchs is an endangered domesticated dog landrace.
As you see from these examples, the Wietingsmoor is a transforming landspace that has a lot of surprises to offer. For now, our tour has ended, but there is still a lot more to discover. We hope you join us again next time to stay updated about the “People and Peatlands” project.
Contact & further literature
Tornow D. 2018. Kursbuch Diepholzer Moorniederung. 1st edition. Schroedersche Buchverlag, Diepholz. 527p.
You can also find me on ResearchGate. If you’re interested in further details, please leave me a comment or get in touch via email: claudia.heindorf@uni-goettingen.de
