In many parts of the world, an increasing demand for productive land constitutes an obstacle for peatland rewetting and threatens pristine peatlands. Land use with plants and machinery adapted to wet site conditions can offer a solution for the trade-off between agricultural production and peatland protection.
Paludiculture is a paradigm shift from adapting site conditions to requirements of conventional agriculture to adapting cultivation to permanent wet conditions. This shift results in significantly lower environmental impacts. Adapted cultivation includes using spontaneously grown or cultivated biomass, adapted machinery, and adapted harvesting processes.
The use of wet peatlands allows for the re-establishment or maintenance of ecosystem services such as sequestration and carbon storage, water and nutrient retention, local climate cooling, and habitat provision for rare species. Paludiculture combines reduction of greenhouse gas emissions through peatland rewetting with avoidance of greenhouse gas emissions through substitution of fossil fuels and raw material. Biomass from different species can be used as food, feed, fiber and fuel but also as raw material for industrial biochemistry or construction. In the long run peat accumulation may even resume, leading to a net sequestration of carbon in the subsoil.
Paludiculture focuses mainly on rewetting formerly drained peatlands. While pristine peatlands provide valuable ecosystem services and ideally should be protected entirely, paludiculture might be a second best solution for sites where the increasing demand for productive land drives peatland drainage.
Beyond the traditional examples for wet peatland use such as reed cutting for thatching roofs, examples of large-scale implementation of paludiculture and long term experience is still rare. Examples for paludicultures are:
Cultivation of Reeds
Reeds (e.g. Common Reed, Reed Canary grass, Cattail) can be used as raw material for construction or as renewable fuel. Cultivation of biomass on rewetted fen peatlands has a twofold beneficial effect on climate. It stops the release of CO2 and N2O from drained peatlands, and contributes to substitution of fossil fuels and raw material.
Cultivation of Black Alder
Alder wood is a valuable material for carpentry, interior fittings, and massive wood furniture. Black Alder (Alnus glutinosa) has been successfully cultivated on rewetted fen peatlands. Medium water tables just below the surface enables a commercial wood harvest combined with peat formation and a positive climate impact.
Each year about 30 million m³ of so-called white peat are used in professional horticulture globally. Cultivation of peat moss (Sphagnum farming) on rewetted bog peatlands can provide a sustainable alternative for white peat. More...
The Database of Potential Paludiculture Plants (DPPP) lists more than 1,000 wetland plants (Abel et al. 2013). However, not all of those plants combine the preservation of the peat carbon stock with an existing or highly probable market demand. To meet these condtions, plants must be perennials, and produce sufficient biomass, some remains to contribute to peat growth, even after aboveground biomass has been harvested. Nutrient and water availability as well as water quality are further factors which restrict the cultivation of paludiculture plants on respective sites. Examples for potential, traditional and tested paludicultures are given in the table below.
Tab. Examples for potential and tested paludicultures (modified after Abel et al. 2013, Joosten et al. 2012).
|Species||Region & Sites||Utilization|
|Alder (Alnus glutinosa)||Central Europe, fen, oligo-eutrotrophic||Timber, fuel|
|Cattail (Typha sp.)||Central Europe, North America, West Africa, fen, polytrophic||Construction material (e.g. insulation), solid fuel, fermentation, fibers|
|Common reed (Phragmites australis)||Europe, China, fen, polytrophic||Construction material (e.g. thatching), paper, solid fuel, fermentation|
|Tropics||Cocoa butter substitute|
|Jelutung (Dyera sp.)||Tropics||Latex|
|Sago (Metroxylon sagu)||Tropics||Starch|
|Sphagnum sp.||Worldwide, bog, oligotrophic||Growing media, revitalization|
|Water buffaloes||Europe, Asia||Cheese (mozarella), meat, conservation grazing|
Paludiculture is not focused on nature conservation but on the productive use of wet peatlands. Its practices may contribute to nature conservation objectives but also may contradict these objectives.
Possible synergies might be:
- Paludiculture can be an intermediate stage between drained use and nature conservation. It might contribute to nature conservation through nutrient removal and vegetation management to establish site conditions necessary for reaching conservation objectives.
- Reduced management costs. Paludiculture may reduce the costs of conservation mowing by providing additional income and reducing biomass disposal costs on sites where regular mowing is necessary to sustain the conservation value.
- Paludiculture as buffer areas. Paludiculture sites on rewetted, formerly degraded peatlands can act as buffer zones between intensively used agriculture sites and protected areas. As a buffer surrounding rewetted conservation areas and natural mires it can reduce the impacts and conflicts from the surrounding areas and reduce nutrient loads of the incoming water. Such wetland buffer zones (WBZ) can also contribute to the water regulation in the conservation area and climate change adaption (van de Riet et al. 2014)
- Paludiculture as corridors. Areas used for paludiculture can form a corridor between conservation areas, facilitating migration of species.
- Paludiculture as mitigation for adaption of land use practices. Wet agriculture can help to increase the acceptance of parties affected by the rewetting. It might help stakeholders who depend on the use of peatland resources to adapt their practices of peatland use (Biancalani et al. 2014). Supporting local communities to adopt alternative production practices and ensure that they profit from the rewetting is crucial for many projects.
Mowing and biomass removal will have some impact on vegetation composition and wildlife. The use of machinery impacts soil and surface structure (microrelief). Rewetted peat soils have a low bearing capacity and a vulnerable upper soil level (sward). Therefore, adapted machinery with ground pressure below 100g per cm² and adapted management practices are necessary (Schröder et al. 2015). For large scale harvesting of biomass a tracked vehicle with a contact area above 11 m² is required.
Further Information & Sources
- Wichtmann, W., Schröder, C. & Joosten, H. (eds.) (2016): Paludiculture - productive use of wet peatlands.
Climate protection - biodiversity - regional economic benefits. 272 p. ISBN 978-3-510-65283-9 .
- Abel, S., Couwenberg, J., Dahms, T. & Joosten, H. (2013): The Database of Potential Paludiculture Plants (DPPP) and results for Western Pomerania. – Plant Div. Evol. 130: 219–228
- Biancalani, R. and Avagyan, A. (eds.) (2014) Mitigation of climate change in agriculture Series 9 - Towards climate-responsible peatlands management: 80-83.
- Gaudig, G., Krebs, M. & Joosten, H. (2017) Sphagnum farming on cut-over bog in NW Germany: Long-term studies on Sphagnum growth. Mires and Peat, Vol. 20, Art. 4
- Joosten H., Tapio-Biström M.-L. & Tol, S. (eds.) (2012): Peatlands - guidance for climate change mitigation by conservation, rehabilitation and sustainable use. Mitigation of climate change in agriculture Series 5. FAO and Wetlands International, Rome.
- Kotowski, W., Jabłońska, E. & Bartoszuk, H. (2013) Conservation management in fens: Do large tracked mowers impact functional plant diversity? Biological Conservation, 167, 292–297
- Schröder, C., Dahms, T., Paulitz, J., Wichtmann, W. & Wichmann, S. (2015): Towards large-scale paludiculture: addressing the challenges of biomass harvesting in wet and rewetted peatlands. Mires and Peat 16: Art. 13.
- van de Riet, B. et al. (2014) Vernatting voor veenbehoud carbon credits & kansen voor paludicultuur en natte natuur in Noord-Holland. Rapportnummer 14015. Landschap Noord-Holland. 40 p.
- Wichmann, S. (2016) Commercial viability of paludiculture: A comparison of harvesting reeds for biogas production, direct combustion, and thatching. Ecological Engineering
- Wichmann, S., Prager, A. & Gaudig, G. (2017) Establishing Sphagnum cultures on bog grassland, cut-over bogs, and floating mats: procedures, costs and area potential in Germany. Mires & Peat 20, Art. 3.
- Wichtmann, W., Schröder, C. & Joosten, H. (eds.) (2016): Paludiculture - productive use of wet peatlands - Climate protection - biodiversity - regional economic benefits.