REstoration and prognosis of PEAT formation in fens. Linking diversity in plant functional traits to soil biological and biogeochemical processes

• Applicant: Professor Dr. Hans Joosten
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems ; Soil Sciences
• Term: from 2016 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 318316996

Belowground biodiversity is formed by fungi, bacteria, archaea, animals and plants that altogether affect soil functioning, particularly by controlling rates of production and decomposition of organic matter. Peat soils, being the most concentrated stores of soil carbon, are formed by a long-term net exceedance of production over decomposition. In Europe most peatlands, especially fens, are severely degraded. Little is known about drivers and pathways that determine whether peat formation and related ecosystem services and biodiversity are truly reinstated after rewetting. Previous research has focused on rainwater-fed bogs with upward growing peatmoss. In groundwater-fed fens roots of sedges grow into the older peat to form displacement peat. REPEAT aims to clarify the mechanisms of peat formation in fens by linking biogeochemical processes to soil community structure and biodiversity, as well as to plant belowground traits. Restoration and paludiculture (biomass harvest) providing vital ecosystem services for mitigation of climate change, regional hydrology, nutrient retention and biodiversity receive special attention. The main research question is: How do environmental factors and human management interact with soil biodiversity in determining rates of peat accumulation in undrained and rewetted fens? This project is the first to systematically address fen peat formation, the predominant mechanism of the temperate zone, using an interdisciplinary, multi-method and multi-site approach. It focuses on both the least disturbed and the most disturbed fens and investigates the restorability of the latter ones, while covering all major EU fen regions. To compare undrained, drained and rewetted fens, we analyse ecosystem processes in-situ in four countries, supplemented by ex-situ mesocosm and laboratory experiments. The project is organised in 8 work packages (Co-ordination and management, State variables, Peat accumulation rates, Decomposers diversity, Producers diversity, Modelling, Scientific integration, Outreach). In the EU, GHG fluxes from most drained fens must be mandatorily accounted from 2021 onwards, which will boost peatland rewetting. Peatland restoration responds also to the EU Biodiversity Strategy 2020 and the CBD Aichi Goals. Guidance on biodiversity-driven mechanisms of carbon sequestration and ecosystem resilience is urgently needed. Stakeholders in participating countries will be integrated through workshops, side events, and field days. Endusers at the EU, national, and regional level are identified. A key stakeholder (Wetlands International) is involved as a consortium partner. The project will advance the knowledge base for process-oriented restoration of fens and will directly impact the application of related policy. REPEAT will consolidate the peatland ecology expertise of five institutions covering the most important European fen regions to obtain the best state-of-the-art knowledge fen peat formation processes.

• DFG Programme: Research Grants
• International Connection: Belgium, Norway, Poland, Romania
• Partner Organisation: Belgian Science Policy Office (BELSPO); Narodowe Centrum Nauki (NCN); The Research Council of Norway (RCN); UEFISCDI
• Co-Investigator: Professor Dr. Jürgen Kreyling
• Cooperation Partners: Professor Dr. Ruurd van Diggelen; Dr. Bente Foereid; Dr. Jenica Hanganu; Professor Dr. Wiktor Kotowski