Background

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 form adapting site conditions to requirements of conventional agriculture to adapting cultivation to permanent wet conditions resulting 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 the re-establishment or maintenance of ecosystem services such as sequestration and carbon storage, water and nutrient retention as well as 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. On the long run peat accu­mulation may even be re-installed leading to a net se­ques­tration of carbon in the subsoil.

Paludiculture mainly aims on rewetting formerly drained peatlands. But even though pristine peatlands provide vulnerable ecosystem services and should therefore be protected entirely, it might be a second best solution for sites where the increasing demand for productive land drives peatland drainage.

Examples

Beside traditional examples for wet peatland use such as reed cutting for thatching, 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, Cattails) can be used as raw material for construction o as renewable fuel. Cultivation of biomass on rewetted fen peatlands has a twofold beneficial effect on climate. It will stop the release of CO2 and N2O from drained peatlands and con­tribute 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.

Plants

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 (perennials of which the aboveground biomass is used) with an existing or highly probable market demand. 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
Cattails (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
Illipe Nut
(Shorea stenoptera)
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

Benefits for nature conservation

Paludiculture is not focused on nature conservation but on the productive use of wet peatlands. Its practices may contribute to nature conservation objectives but might also contradict these.

Possible synergies might be:

Paludiculture as intermediate stage between drained use and nature conservation. Paludiculture can be intermediate stage between drained use and nature conservation. It might contribute through nutrient removal and vegetation management to establish site conditions necessary to each conservation objectives.
Reduced management costs It 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 (s fig. XX. B) (van de Riet et al. 2014)
Paludiculture as corridor Areas used for paludiculture can form a corridor between two conservation areas, facilitating migration of species.
Paludiculture as mitigation for mitigation and adaptation 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.

Impact

Mowing and biomass removal will have impact on vegetation composition and wildlife. The use of machinery will have impact on soil and surface structure (microrelief). Rewetted peat soils have a low bearing capacity and a vulnerable 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 tracked vehicle with a contact area above 11 m² are required.

Further information

[1]   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.

[2]   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

[3]   Biancalani, R. and Avagyan, A. (eds.) (2014) Mitigation of climate change in agriculture Series 9 - Towards climate-responsible peatlands management: 80-83.

[4]   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

[5]   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.

[6]   Kotowski, W., Jabłońska, E. & Bartoszuk, H. (2013) Conservation management in fens: Do large tracked mowers impact functional plant diversity? Biological Conservation, 167, 292–297

[7]   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.

[8]   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.

[9]   Wichmann, S. (2016) Commercial viability of paludiculture: A comparison of harvesting reeds for biogas production, direct combustion, and thatching. Ecological Engineering

[10]  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.

[11]  Wichtmann, W., Schröder, C. & Joosten, H. (eds.) (2016): Paludiculture - productive use of wet peatlands - Climate protection - biodiversity - regional economic benefits.