Paludiculture in temperate fens to combat eutrophication, biodiversity loss, and climate change

Draining temperate fen peatlands created multiple problems such as greenhouse gas emissions, eutrophication and subsidence due to peat mineralization, but also loss of highly specialized biodiversity. Based on recent own publications and (not yet published) studies, we here explore the potential of paludiculture, i.e. the wet use of peatlands, in tackling the multiple challenges mentioned above. Rewetting effectively curbs carbon losses (Tanneberger et al. 2020, 2021), but rewetted fens are more enriched in nutrients and differ in vegetation composition compared to natural fens (Kreyling et al. 2021). Brown mosses, for instance, are outcompeted by tall helophytes (Jaszczuk et al. 2022). Harvesting aboveground plant biomass can effectively reduce nutrient loads (Hinzke et al. 2021a), while belowground production leading to peat formation is even enhanced by high nutrient loads (Hinzke 2021b). Paludiculture with productive species such as Typha, however, is possible even with low nutrient availability (Haldan et al. 2022). If productive species such as Phragmites are actively introduced for paludiculture, genotypes should carefully be selected as they differ strongly in performance (Haldan et al. unpublished). Paludiculture has the potential to foster conservation targets across multiple taxa such as plants, arthropods, and birds (Martens et al. unpublished). Drought events occur with increasing intensity and frequency idue to climate change. High decomposition under these circumstances, however, is balanced by increased root production (Schwieger et al. 2020) due to an elongated belowground growing season (Schwieger et al. 2022). We conclude that paludiculture is a viable management option for rewetted fens that can curb multiple environmental challenges such as greenhouse gas emissions, eutrophication and biodiversity loss. Haldan K, et al. (2022) Typha for paludiculture—Suitable water table and nutrient conditions for potential biomass utilization explored in mesocosm gradient experiments. Ecology and Evolution 12: e9191. https://doi.org/10.1002/ece3.9191Hinzke T, et al. (2021a) Can nutrient uptake by Carex counteract eutrophication in fen peatlands? Science of the Total Environment 785: 147276.Hinzke T, et al. (2021) Potentially peat-forming biomass of fen sedges increases with increasing nutrient levels. Functional Ecology 35, 1579-1595. IJaszczuk I, et al. (2022) Physiological responses of fen mosses along a nitrogen gradient point to competition restricting their fundamental niches. Oikos DOI: 10.1111/oik.09336Kreyling J, et al. (2021) Rewetting does not return drained fen peatlands to their old selves. Nature Communications 12: 5693.Schwieger S, et al. (2020) Wetter is better: rewetting of minerotrophic peatlands increases plant production and moves them towards carbon sinks in a dry year. Ecosystems 24: 1093–1109.Schwieger S, et al. (2022) Rewetting prolongs belowground growing season in minerotrophic peatlands and mitigates negative drought effects. Journal of Applied Ecology DOI 10.1111/1365-2664.14222.Tanneberger F., et al. (2020) The power of nature-based solutions: how peatlands can help us to achieve key EU sustainability objectives. Advanced Sustainable Systems 20000146, DOI 10.1002/adsu.202000146Tanneberger F., et al. (2021) Towards net zero CO2 in 2050: An emission reduction pathway for organic soils in Germany. Mires and Peat 27, Article 05, doi: 10.19189/MaP.2020.SNPG.StA.1951.