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

地下生物多样性是由真菌、细菌、古生菌、动物和植物形成的，它们共同影响土壤功能，特别是通过控制有机物的生产和分解速度。泥炭土是土壤碳最集中的储存库，是由长期的净产量超过分解量而形成的。在欧洲，大多数泥炭地，尤其是沼泽，都严重退化。泥炭的形成以及相关的生态系统服务和生物多样性是否在复湿后真正恢复，其驱动因素和途径尚不清楚。以前的研究主要集中在由雨水喂养的泥炭层向上生长的沼泽上。在地下水喂养的沼泽中，莎草的根长到老泥炭中，形成置换泥炭。REPEAT旨在通过将生物地球化学过程与土壤群落结构和生物多样性以及植物地下性状联系起来，阐明沼泽泥炭形成的机制。为减缓气候变化、区域水文、养分保留和生物多样性提供重要生态系统服务的恢复和古农业（生物量收获）受到特别关注。主要的研究问题是：环境因素和人类管理如何与土壤生物多样性相互作用，决定不排水和再湿润沼泽的泥炭积累率？该项目首次采用跨学科、多方法和多地点的方法，系统地研究了温带地区主要的泥炭形成机制。在覆盖欧盟所有主要沼泽区的同时，重点研究了受干扰最小和受干扰最大的沼泽区，并研究了后者的可恢复性。为了比较不排水，排水和再湿润的沼泽，我们分析了四个国家的原位生态系统过程，并辅以异地生态系统和实验室实验。该项目分为8个工作包（协调和管理、状态变量、泥炭积累率、分解者多样性、生产者多样性、建模、科学整合、外联）。在欧盟，从2021年起，大多数排水沼泽的温室气体通量必须被强制计算在内，这将促进泥炭地的再湿润。泥炭地恢复也符合欧盟《2020年生物多样性战略》和《生物多样性公约爱知目标》。迫切需要关于生物多样性驱动的碳固存和生态系统恢复机制的指导。参与国的利益攸关方将通过讲习班、会外活动和实地考察日进行整合。确定了欧盟、国家和地区级别的最终用户。一个主要的利益相关者（湿地国际）作为财团的合作伙伴参与其中。该项目将促进以过程为导向的沼泽恢复的知识基础，并将直接影响相关政策的应用。REPEAT将整合覆盖欧洲最重要沼泽地区的五个机构的泥炭地生态学专业知识，以获得最先进的泥炭形成过程知识。

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.