Resources

Scientific publications

Improved uncertainty estimates for eddy covariance-based carbon dioxide balances using deep ensembles for gap-filling

Authors:

Vekuri, Henriikka; Tuovinen, Juha-Pekka; Kulmala, Liisa; Aurela, Mika; Thum, Tea; Liski, Jari; Lohila, Annalea

Summary:

Eddy covariance (EC) measurements of carbon dioxide (CO

_{2}

) fluxes are commonly used to determine CO

_{2}

balances of ecosystems. However, comparisons between experimental treatments, environmental controls or measurement sites are not meaningful without proper uncertainty estimates for the balances. We studied how random and systematic errors depend on the amount of missing data and whether the uncertainty estimates produced by popular gap-filling methods, including tree-based machine learning methods, neural networks and marginal distribution sampling (MDS), are in line with these errors. Using synthetic data created for European forest sites, we found that when the proportion of missing data increased from 30% to 90%, the random uncertainty related to gap-filling (2

σ_{rnd}

, computed from observed model errors) increased from approximately 10 g C m⁻² y⁻¹ up to 25–75 g C m⁻² y⁻¹ depending on the site and gap-filling method. Ensembles of neural networks (deep ensembles) had smaller random errors than the standard EC gap-filling method MDS, and also produced improved uncertainty estimates for the CO

_{2}

balances. Long gaps of up to one month caused random uncertainty of mostly less than 50 g C m⁻² y⁻¹; however, a long gap during a dry and warm period that was inadequately represented in the measurements caused random uncertainty of up to 99 g C m⁻² y⁻¹. Deep ensembles produced well-calibrated uncertainty estimates also for the long gaps, except for the most difficult cases when long gaps occurred during periods of active change in the ecosystem. The uncertainty estimates produced by MDS for long gaps were clearly too small. Tree-based machine learning methods produced well-calibrated uncertainty estimates for short-term fluxes but not for balances and, unlike deep ensembles, did not extrapolate outside the training data.

Towards a remote sensing-based assessment of carbonemissions from peatlands

Authors:

Pouya Ghezelayagh, Andrzej Kamocki, Piotr Banaszuk, Mateusz Grygoruk

Summary:

Among greenhouse gases-generating sources, biosphere sources from natural carbon (C) reservoirs play a significant role. A vital component of the biosphere is peatlands—the largest natural terrestrial carbon storage on the earth. Peatlands function as both C sink and C source, showing their pivot role in mitigating GHGs. Releasing C results from peat oxidation—the decomposition of organic matter in the peat. This decomposition reduces the volume of peat and, hence, causes subsidence. This study introduces an exclusive remote-sensing-based framework for estimating carbon emissions from peatlands using subsidence rates. This framework integrates peat properties—bulk density and soil organic carbon—with the oxidated peat subsidence, which refers to the proportion of subsidence attributed to the oxidation process rather than shrinkage. Achieving a fully remote-sensing-based approach promises time-effective, cost-effective, and consistent C emission monitoring even in unreachable places in peatlands, addressing the critical need for global climate change mitigation strategies. However, this achievement requires collaborative efforts among researchers to implement it in other sites to improve dataset accuracy for each parameter. By improving this framework, the scientific community can pave the way for robust, large-scale assessments of peatland C emission.

Phosphorus transformations and leaching potential in rewetting drained peatlands: Exploring the influence of land use and temperature

Authors:

Atif Muhmood, Haonan Guo, Lorenzo Pugliese and Shubiao Wu

Summary:

Understanding phosphorus (P) transformation dynamics during peatland rewetting is crucial for developing effective management strategies, supporting ecological restoration initiatives and mitigating potential environmental risks. This incubation study explored the temporal variations in P transformation in peatlands under different land uses (cut grass, grazing, unmanaged) along with the potential risk of leaching by simulating rewetting conditions for four months at varying temperatures (10 and 20 °C). Overall, only a small fraction of the initial total phosphorus (P) was leached during rewetting. Among land uses, soils under grazing showed the highest release (0.34%), followed by cut grass (0.19%) and unmanaged land (0.13%). A higher risk of leaching at the beginning of the rewetting was observed to be associated with a high transformation rate of P from organic form to inorganic form but mitigated by resorption with ongoing rewetting. Soil organic carbon, initial contents of P, iron, and aluminium as well as temperature were found to be the main factors controlling P transformation and leaching during the rewetting process. Increasing incubation temperature from 10 °C to 20 °C raised P release by 33–41%. Moreover, a projected 1.5 °C increase in temperature due to climate change is estimated to increase the rate of phosphorus (P) transformation and release by approximately 24%, based on temperature sensitivity analysis. More research is needed to comprehensively explore complex interactions involving seasonal variations, microbial activity, and geological processes. This is also necessary for a holistic understanding of how these ecosystems may respond to ongoing climate changes.

Issues of Peatland Restoration Across Scales: A Review and Meta-Analysis

Authors:

Rinda Kustina, Jessica Canchig Pilicita and Mateusz Grygoruk

Summary:

Although peatland restoration has been widely promoted as a strategy for reducing carbon emissions and restoring hydrological function, its effectiveness remains context-dependent and highly variable across regions and methods. This study presents a systematic review and meta-analysis of 52 peer-reviewed studies from 2014 to 2024, synthesizing the ecohydrological impacts of restoration across multiple spatial scales and implementation types. In tropical peatlands, restoration frequently reduced CO₂ emissions by more than 65,000 kg·ha⁻¹·yr⁻¹ and increased carbon sequestration up to 39,700 kg·ha⁻¹·yr⁻¹, with moderate CH₄increases (~450 kg·ha⁻¹·yr⁻¹). In boreal sites, CO₂ reductions were generally below 25,000 kg·ha⁻¹·yr⁻¹, with long-term carbon accumulation reported in other studies, typically around 2–3 tCO₂·ha⁻¹·yr⁻¹. Higher values in our dataset likely reflect the limited number of boreal studies and the influence of short-term measurements. Across all regions, restoration was also associated with an average rise in WTD up to 10 cm. These averages were derived from studies conducted across diverse climatic zones, showing high standard deviations, indicating substantial inter-site heterogeneity. These differences emphasize the need for region-specific assessments rather than global generalizations, highlighting the importance of adaptive restoration strategies that balance carbon dynamics with hydrological resilience in the face of climate change.

Restoration is an investment. Comparing restoration costs and ecosystem services in selected European wetlands

Authors:

Karolina Strzęciwilk, Mateusz Grygoruk

Summary:

Wetland restoration aims to restore key environmental functions to degraded ecosystems, but it comes with costs, which can hinder public acceptance of restoration. However, the benefits we gain from restoration can be valued higher than the costs of restoration, making restoration an investment. This study aimed to analyse the costs of wetland restoration projects implemented in selected European countries. We analysed 100 projects implemented between 1996 and 2019. Results showed increasing numbers of wetland restoration projects implemented in Europe since the early 21 st century. The total budgets for wetland restoration projects rose in the years reviewed, increasing the average project budgets. The average cost of restoring 1 hectare of wetland in the 100 projects analysed was 9,084 EUR∙ha −1 , which, including the amortisation rate of actions implemented to restore wetlands, allowed us to estimate the average unit cost of wetland restoration to 227 EUR∙ha−1 ∙y−1 . Available information on the average values of ecosystem services provided by wetlands (estimated to be 4,011 EUR∙ha−1 ∙y−1 ) allowed us to conclude that the value of sustainably managed wetlands is from ten to fifty times higher than the average wetland restoration costs. Our findings indicate that wetland restoration should be considered an investment, as the revenue the society gains from reestablished wetlands outweighs the costs of their restoration. These findings contribute to the international discussion on wetland restoration’s role in boosting environmental and economic resilience, underscoring the need for regular restoration efforts to benefit ecosystems, economies, and societies.

Analyzing who is relevant to engage in environmental decision-making processes by interests, influence and impact: The 3i framework

Authors:

M.S. Reed, E.A. Jensen, S. Noles, D. Conneely, H. Kendall, M. Raley, A. Tarrant,
N. Oakley, C. Hinson, V. Hoare, K. Marshall, L. Pugliese

Summary:

Outcomes in participatory environmental processes are strongly affected by choices about who is engaged. Inclusive engagement diversifies the range of interests and perspectives represented, including those from vulnerable and marginalized groups, ultimately contributing to more socially and environmentally sustainable and equitable outcomes. However, existing “stakeholder analysis” methods often bias participant identification away from disenfranchised groups with limited pre-existing interest or influence, instead favoring the most easily accessed and influential stakeholders. This paper draws on research impact theory and practice to propose a new, more inclusive approach, adding impact to the existing interest and influence criteria (which each begin with the letter “i”, hence the 3i framework) that are typically used to identify, categorize and prioritize those who are relevant to be included or excluded from engagement processes. As part of this proposed 3i analysis approach, we articulate a new typology of relevant parties to engage in environmental decision-making processes, including: uninterested; uninterested and impacted; uninterested influencers; disinterested, influential and impacted; only interested; interested and impacted; interested influencers; and interested, influential and impacted. Except for the first group, all types of relevant parties should be considered for engagement wherever possible, with participation strategies tailored to their specific 3i profile. The approach was developed and refined through a series of workshops before developing it into a survey instrument that was piloted to gather 3i data efficiently across several national contexts. Survey findings are presented for a case study identifying those relevant to wetland and peatland restoration in a Scottish catchment. If widely adopted, the 3i framework would be the most consequential change in stakeholder analysis methods since the introduction of interest-influence matrices in the 1980s.

Eco-nano solutions for rapid phosphorus recovery: Closing the loop for sustainable agriculture

Authors:

Atif Muhmood, Shihao Cui, Jingyu Wang, Deyong Wang, Lorenzo Pugliese,
Shubiao Wu

Summary:

Efficient phosphorus (P) removal from agricultural drainage is crucial for making its removal and recovery economically viable and operationally feasible. This study evaluated cost-effective, green-synthesized nanoparticles (using grass extract) for rapid and efficient P adsorption. Batch experiments were conducted to assess the effect of pH, P concentration, adsorbent dosage, contact time, and temperature on P adsorption. The nanoparticles removed 20 mg/L of P in 5 min, demonstrating their significant potential for effective adsorption in short retention time. They achieved a maximum adsorption capacity of 77.5 mg g⁻¹, outperforming their chemically synthesized counterparts. Moreover, smaller particles exhibited faster initial adsorption, while larger ones contributed more to overall adsorption over time. Modeling results revealed that rapid initial P adsorption was driven by physisorption, while chemisorption controlled the rate of adsorption in the later stages. After five regeneration cycles, the nanoparticles retained over 50 % of their adsorption capacity, demonstrating strong reusability potential. Further research is needed to optimize these nanoparticles for P removal from dynamic agricultural drainage, offering a cost-effective and sustainable solution for P management.

Natural capital approaches to decision-making for collaborative landscape governance

Authors:

Jayne H. Glass, Kerry Waylen, Mark S. Reed, Leo Peskett, Brady Steven

Summary:

This study explores if and how natural capital approaches can support collaborative landscape governance. We selected six initiatives across the UK that have taken varied approaches to working with natural capital. We assessed how they have articulated, described and valued their landscapes and natural systems, and the consequences of doing so. We found that processes of systematically describing natural assets and their benefits can stimulate local investment in ecosystem markets and bring people together to co-produce plans. However, efforts to monetarily value natural capital assets were not always necessary: in some cases, new partners and resources were enroled without monetary valuations. These findings challenge the current emphasis on valuation framings in natural capital approaches. They show how natural capital approaches can help address the simultaneous challenges of connecting disparate priorities and securing new funding sources. This offers insights for international efforts to support collaborative landscape governance that delivers multiple benefits for people and nature.

Constructing Marginal Abatement Cost Curves for Scottish Peatlands: Data integration approach and challenges

Authors:

Daniel Urban, Klaus Glenk, Daniel Fletcher

Summary:

This report provides a detailed overview of methods, data sources, data management approaches and limitations of the up-to-date work on cost effectiveness of peatland restoration projects funded in Scotland under the Peatland Action (PA) grant programme.
The dataset and corresponding data management protocol constitute deliverables and inputs into further analysis of the CentrePeat project under the Scottish Government’s (SG) Strategic Research Programme (SRP), the European Union’s Wet Horizons project and the “Understanding Peatland Restoration Costs and Contractor Capacity” report commissioned by ClimateXChange. At its centre stands the individual site-level database developed under the “Costs of Peatland Restoration” line of work by Glenk et al., (2020,2021,2022).
For the purpose of exploring and evaluating relevant spatial factors of variation in peatland restoration costs and activities, an extensive list of spatially explicit of environmental, meteorological, topographic and infrastructural datasets was identified and sourced. Using various GIS tools, the information from these data sources was extracted and merged with the SRUC/PA cost database.
A detailed overview of the data used is presented in the “Data Sources” section. The methods and assumptions used are in the “Merging the cost database with external data” part followed by “Main limitations” outlining challenges with the chosen approach accompanied by practical examples. The extended database functions as a basis for construction of the marginal abatement cost curves (MACC), a multivariate explanatory regression model and a spatial cost prediction model for determining cost effective pathways for scaling up future peatland restoration efforts.

Assessing modelled methane emissions over northern wetlands by the JULES-HIMMELI model

Authors:

Yao Gao, Eleanor J. Burke, Sarah E. Chadburn, Maarit Raivonen, Tiina Markkanen, Mika Aurela, Lawrence B. Flanagan, Krzysztof Fortuniak, Elyn Humphreys, Annalea Lohila, Tingting Li, Ivan Mammarella, Olli Nevalainen, Mats B. Nilsson, Włodzimierz Pawlak, Aki Tsuruta, Huiyi Yang, Tuula Aalto

Summary:

Northern wetlands are considered to be one of the most significant natural sources of methane (CH₄) emissions. The default wetland CH₄ emission scheme in JULES, a current state-of-art land surface model, only takes into account the CH₄ emissions from inundated wetland areas in a simple manner based on soil temperature and substrate availability. In this work, a process-based peatland CH₄ emission model HIMMELI was integrated with JULES, and the HIMMELI parameters were optimized with measured CH₄ flux at six northern wetland sites for each site separately or multi-sites simultaneously. The simulated CH₄ emission was significantly improved when using the optimized parameter values, with the bias of 54.88 mg m⁻² d⁻¹ averaged across all the studied sites in the simulation using the default parameter (DPR) values being reduced to −0.70 mg m⁻² d⁻¹ in the simulations using parameters values derived from the single site optimization (SSO) for each site. In the simulations using parameters values from the averages of single site optimization (SSO_AVG) and the multi-site optimization (MSO), the biases averaged across all the studied sites were −7.39 mg m⁻² d⁻¹ and −8.36 mg m⁻² d⁻¹, respectively. The MSO simulations demonstrated more stable root mean square error (RMSE) between the simulated and observed methane emissions than the SSO_AVG simulations over the studied sites, when the RMSEs of SSO simulations were used as reference points. To further reduce the uncertainties in the simulated CH₄ emissions by the JULES-HIMMELI model, model processes related to the environment conditions (e.g. water table, soil carbon and vegetation) of wetland and northern wetland CH₄ emission processes (e.g. snow and ice covering effect) are suggested to be improved in JULES and HIMMELI, respectively. This study presents a comprehensive analysis of the impact of different parameters on the CH₄ emission in the JULES-HIMMELI model and obtains optimal parameter values for modelling CH₄ emissions at the studied northern wetlands. These findings pave the way for accurate regional estimates of northern wetland CH₄ emission.

Responsible research impact: Ethics for making a difference

Authors:

Eric Allen Jensen, Mark S Reed, James Daybell, Louise Rutt, Aaron M Jensen, Gabriella Arrigoni, Marta Ballesteros, Sadiq Bhanbhro, Bethann G Merkle, Caitlin Hafferty, Philly Iglehart, Sawsan Khuri, Andrzej Klimczuk, Ian D Marder, Daniel Milosavljevic, Josmel Pacheco-Mendoza, Ursula Pool, Simon Robinson, Lindsay C Stringer, Steve Taylor, Anne H Toomey, Daniela Martin, Lisa Louise Taylor-Sayles, Andrew N Makohon-George, Russell T Rodrigo

Summary:

The need for ethical guidelines that support and empower researchers who aim to enhance the societal impact of research has become critical. Recognizing the growing emphasis on research impact by governments and funding bodies worldwide, this article investigates the often overlooked ethical dimensions of generating and evaluating research impact. We focus on ethical issues and practices that are specific to the process of intentionally working to develop societal impacts from research. We highlight the complexities and ethical dilemmas encountered when researchers engage with non-academic groups, such as policymakers, industries, and local communities. Through a combination of literature review and insights from participatory workshops, the article identifies key issues and offers a new ethical framework for responsible research impact. This framework aims to guide researchers and institutions through the process of limiting potential harm while delivering societal benefits in a way that is realistic and balanced. The aim is to establish ethical practices for engagement and impact, without making the process so onerous that researchers are less likely to undertake such activities. The article concludes with actionable recommendations for policymakers, research funders, research performing organizations, institutional review boards and/or ethics committees, and individual researchers. Making use of such recommendations can foster an ethically responsible approach to research impact across academic disciplines.

External and internal drivers behind the formation, vegetation succession, and carbon balance of a subarctic fen margin

Authors:

Teemu Juselius-Rajamäki, Sanna Piilo, Susanna Salminen-Paatero, Emilia Tuomaala, Tarmo Virtanen, Atte Korhola, Anna Autio, Hannu Marttila, Pertti Ala-Aho, Annalea Lohila, and Minna Väliranta

Summary:

Peatlands are the most carbon-dense terrestrial ecosystem, and recent studies have shown that the northern peatlands have been (and still are) expanding into new areas. However, depending on the vegetation and hydrological regime in the newly initiated areas, the climate forcing may vary. If these new areas developed as wet fen-type peatlands with high methane emissions, they would initially have a warming effect on the climate. On the other hand, if development began as dry bog-type peatlands, these new peatland areas would likely act as a strong carbon sink from early on. However, although some research has concentrated on the expansion of the new northern peatland areas, there remains a significant lack of studies on the successional development of the newly initiated peatland frontiers. In this research, we combine paleoecological, remote-sensing, and hydrological modeling methods to study the expansion and successional pathway dynamics in a subarctic fen margin in Finnish Lapland and discuss possible implications for the carbon balance of these marginal peatland areas. Our results show that (1) the studied peatland margins started to develop ca. 2000 years ago and have continued to expand thereafter and (2) this expansion has occurred in nonlinear fashion. In addition, wet fen-type vegetation persisted in the studied margin for the majority of the developmental history, and only dryer conditions after the Little Ice Age instigated the fen-to-bog transition. However, a notable part of the fen margins in the Lompolonvuoma and Lompolojänkkä basins has remained wet fen-type vegetation, and the persistence of this vegetation type was likely caused by the hydrological conditions in the peatland and surrounding catchment. Our findings show a large variation in the peatland expansion and succession dynamics, even within a single peatland basin. Although changes in climate conditions initiated the fen-to-bog process in some margins, some vegetation remained in the wet fen stage, showing resilience to allogenic forcings. Thus, when estimating the peatland carbon stocks and predicting the future trajectories for peatland development, this heterogeneity should be taken into account to avoid errors caused by the oversimplification of peatland lateral expansion dynamics.

Planetary boundaries under a land-based climate change mitigation scenario with a food demand transformation: a modelling study

Authors:

Felicitas D Beier, Jan Philipp Dietrich, Jens Heinke, Gabriel Abrahao, Patrick von Jeetze, Benjamin Leon Bodirsky, Michael Crawford, Florian Humpenöder, Leon Merfort, Isabelle Weindl, Mario Herrero, Daniel Mason-D’Croz, Johan Rockström, Marina Sundiang, Sofie te Wierik, Anna Norberg, David Klein, Christoph Müller, Hermann Lotze-Campen, Alexander Popp

Summary:

Background :Ambitious climate change mitigation in all economic sectors is crucial for limiting global warming. Cost-effective mitigation pathways to keep global average temperature increases below 1·5°C by the end of the 21st century often rely on land-based greenhouse gas (GHG) emission reductions, increased land-based carbon uptake and biomass supply to other sectors (eg, energy and transport), and demand-side changes in the food system. To evaluate the broader sustainability of land-based climate change mitigation action, we evaluated synergies and tradeoffs of individual and combined supply-side mitigation measures across five planetary boundaries. We also examined the role of a food demand transformation aligned with the dietary recommendations of the updated planetary health diet defined in the forthcoming EAT–Lancet Commission 2.0 report in shaping planetary boundary outcomes.

Methods: In this modelling study, we used the dynamic land-system modelling framework MAgPIE to assess the consequences of land-based GHG reductions, increased land-based carbon uptake, increased biomass supply to other sectors, and a food-system transformation towards the planetary health diet including food waste reductions on five planetary boundary domains (climate change, nitrogen, land-system change, freshwater use, and biosphere integrity) relative to a reference scenario without land-system mitigation throughout the century. For each planetary boundary control variable, we calculated the level of planetary boundary transgression (ie, the extent to which scenario outcomes exceeded the defined safe operating space) and assessed the contributions of land-based mitigation strategies to reducing planetary boundary transgressions projected for the reference scenario.

Findings: Our projections show that a food-system transformation together with ambitious land-system and energy-system climate change mitigation can limit global warming to below 1·5°C by 2100, while also reducing planetary boundary transgression (particularly for the climate change, land-system change, biosphere integrity, and nitrogen planetary boundaries). However, a safe operating space was not achieved through these mitigation measures, as most planetary boundaries were still projected to remain transgressed by the end of the 21st century. Increased bioenergy supply alone worsened planetary boundary transgression when only looking at land-system impacts, but combining increased bioenergy supply with GHG pricing in the land system alleviated these trade-offs. Food waste reductions and dietary shifts towards the planetary health diet were projected to ease pressures on the land system and reduce planetary boundary transgression of all assessed planetary boundaries.

Interpretation: This research highlights the importance of considering multiple planetary boundaries and the interactions between various mitigation strategies when assessing climate mitigation action in the land system to avoid negative consequences for other aspects of the environment. Following an ambitious climate change mitigation pathway compatible with the Paris Agreement results in a transgression of all assessed five planetary boundaries by 2100. However, the combination of the land-system mitigation measures included in this study produced a substantial shift towards the safe operating space for humanity.

Assessing CO₂ Fluxes for European Peatlands in ORCHIDEE-PEAT With Multiple Plant Functional Types

Authors:

Liyang Liu, Chunjing Qiu, Yi Xi, Elodie Salmon, Aram Kalhori, Rebekka R. E. Artz, Christophe Guimbaud, Matthias Peichl, Joshua L. Ratcliffe, Koffi Dodji Noumonvi, Efrén López-Blanco, Jiří Dušek, Tiina Markkanen, Torsten Sachs, Mika Aurela, Thu-Hang Nguyen, Annalea Lohila, Ivan Mammarella, Philippe Ciais

Summary:

Peatlands are significant carbon reservoirs vulnerable to climate change and land use change such as drainage for cultivation or forestry. We modified the ORCHIDEE-PEAT global land surface model, which has a detailed description of peat processes, by incorporating three new peatland-specific plant functional types (PFTs), namely deciduous broadleaf shrub, moss and lichen, as well as evergreen needleleaf tree in addition to previously peatland graminoid PFT to simulate peatland vegetation dynamic and soil CO₂ fluxes. Model parameters controlling photosynthesis, autotrophic respiration, and carbon decomposition have been optimized using eddy-covariance observations from 14 European peatlands and a Bayesian optimization approach. Optimization was conducted for each individual site (single-site calibration) or all sites simultaneously (multi-site calibration). Single-site calibration performed better, particularly for gross primary production (GPP), with root mean square deviation (RMSD) reduced by 53%. While multi-site calibration showed limited improvement (e.g., RMSD of GPP reduced by 22%) due to the model’s inability to account for spatial parameter variations under different climatic contexts (trait-climate correlations). Site-optimized parameters, such as Q₁₀, the temperature sensitivity of heterotrophic respiration, revealed strong empirical relationships with environmental factors, such as air temperature. For instance, Q₁₀ decreased significantly at warmer sites, consistent with independent field data. To improve the model by using the lessons from single-site optimization, we incorporated two key trait-climate relationships for Q₁₀ and V_cmax (maximum carboxylation rate) into a new version of the ORCHIDEE-PEAT models. Using this description of spatial variability of parameters holds significant promise for improving the accuracy of carbon cycle simulations in peatlands.

Developing and Validating Species Distribution Models for Wetland Plants Across Europe

Authors:

Ojaswi Sumbh, Marjon Hellegers, Valerio Barbarossa, Renata Ćušterevska, Borja Jiménez-Alfaro, Łukasz Kozub, Francesca Napoleone, Zvjezdana Stančić, Aafke M. Schipper

Summary:

Drainage, agricultural conversion, and climate change threaten wetlands and their unique biodiversity. Species distribution models (SDMs) can help to identify effective conservation measures. However, existing SDMs for wetland plants are often geographically limited, miss variables representing hydrological conditions, and neglect moss species, essential to many wetlands. Here, we developed and validated SDMs for 265 vascular plant and moss species characteristic of European wetlands, using environmental variables representing climate, soil, hydrology, and anthropogenic pressures. We validated the spatial predictions of the SDMs through cross-validation and against independent data from the Global Biodiversity Information Facility (GBIF). Further, we validated the niche optima of the species, as obtained from the modelled species response curves, with empirical niche optima. The spatial validation revealed good predictive power of the SDMs, especially for diagnostic mosses, for which we obtained median cross-validated values of the area under the curve (AUC) and true skill statistic (TSS) of 0.93 and 0.73, respectively, and a median true positive rate (TPR) based on GBIF records of 0.77. SDMs of diagnostic vascular plants performed well, too, with median AUC, TSS, and TPR of 0.91, 0.69, and 0.67, respectively. SDMs of non-diagnostic plants had the lowest performance, with median AUC, TSS, and TPR values of 0.84, 0.53, and 0.62, respectively. Correlations between modelled and empirical niche optima were typically in the expected direction. Climate variables, particularly the mean temperature of the coldest month, were the strongest predictors of species occurrence. At the same time, groundwater table depth was a significant predictor for diagnostic vascular plants but not for mosses. We concluded that our SDMs are suitable for predicting broad-scale patterns of wetland plant species distributions as governed by climatic conditions. Alternative or additional variables or a different modelling approach might be needed to represent better the local heterogeneity in the hydrological conditions of wetlands.

Future methane fluxes of peatlands are controlled by management practices and fluctuations in hydrological conditions due to climatic variability

Authors:

Vilna Tyystjärvi, Tiina Markkanen, Leif Backman, Maarit Raivonen, Antti Leppänen, Xuefei Li, Paavo Ojanen, Kari Minkkinen, Roosa Hautala, Mikko Peltoniemi, Jani Anttila, Raija Laiho, Annalea Lohila, Raisa Mäkipää, and Tuula Aalto

Summary:

Peatland management practices, such as drainage and restoration, have a strong effect on boreal peatland methane (CH₄) fluxes. Furthermore, CH₄ fluxes are strongly controlled by local environmental conditions, such as soil hydrology, temperature and vegetation, which are all experiencing considerable changes due to climate change. Both management practices and climate change are expected to influence peatland CH₄ fluxes during this century, but the magnitude and net impact of these changes is still insufficiently understood. In this study, we simulated the impacts of two forest management practices, rotational forestry and continuous cover forestry, as well as peatland restoration, on hypothetical forestry-drained peatlands across Finland using the land surface model JSBACH (Jena Scheme for Biosphere–Atmosphere Coupling in Hamburg) coupled with the soil carbon model YASSO and a peatland methane model HIMMELI (Helsinki Model of Methane Buildup and Emission for Peatlands). We further simulated the impacts of climatic warming using two RCP (Representative Concentration Pathway) emission scenarios, RCP2.6 and RCP4.5. We investigated the responses of CH₄ fluxes, soil water-table level (WTL), soil temperatures and soil carbon dynamics to changes in management practices and climate. Our results show that management practices have a strong impact on peatland WTLs and CH₄ emissions that continues for several decades, with emissions increasing after restoration and clearcutting. Towards the end of the century, WTLs increase slightly, likely due to increasing precipitation. CH₄ fluxes have opposing trends in restored and drained peatlands. In restored peatlands, CH₄ emissions decrease towards the end of the century following decomposition of harvest residue in the top peat layers despite increasing WTLs, while in drained peatland forests sinks get weaker and occasional emissions become more common, likely due to rising WTLs and soil temperatures. The strength of these trends varies across the country, with CH₄ emissions from restored peatlands decreasing more strongly in southern Finland, and forest soil CH₄ sinks weakening most in northern Finland.

Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data

Authors:

Helena Rautakoski, Mika Korkiakoski, Jarmo Mäkelä, Markku Koskinen, Kari Minkkinen, Mika Aurela, Paavo Ojanen, and Annalea Lohila

Summary:

The urgent need to mitigate climate change has evoked a broad interest in better understanding and estimat ing nitrous oxide (N2O) emissions from different ecosystems. Part of the uncertainty in N2O emission estimates still comes from an inadequate understanding of the temporal and small-scale spatial variability of N2O fluxes. Using 4.5 years of N2O flux data collected in a drained peatland forest with six automated chambers, we explored temporal and small-scale spatial variability of N2O fluxes. A random forest with conditional inference trees was used to find immediate and delayed relationships between N2O flux and environmental conditions across seasons and years. The spatiotemporal variation of the N2O flux was large, with daily mean N2O flux varying between −10 and +1760 μg N2O m−2 h−1 and annual N2O budgets of different chambers between +60 and +2110 mg N2O m−2 yr−1. Spatial differences in fluxes persisted through years of different environmental conditions. Soil moisture, water table level, and air temperature were the most important variables explaining the temporal variation of N2O fluxes. N2O fluxes responded to precipitation events with peak fluxes measured on average 4 d after peaks in soil moisture and water table level. The length of the time lags varied in space and between seasons indicating possible interactions with temperature and other soil conditions. The high temporal variation in N2O flux was related to (a) temporal variation in environmental conditions, with the highest N2O fluxes measured after summer precipitation events and winter soil freezing, and (b) to annually varying seasonal weather conditions, with the highest N2O emissions measured during wet summers and winters with discontinuous snow cover. Climate change may thus increase winter N2O emissions, which may be offset by lower summer N2O emissions in dry years. The high sensitivity of N2O fluxes to seasonal weather conditions suggests increasing variability in annual peatland forest N2O budgets as the frequency of extreme weather events, such as droughts, is predicted to
increase.

A practical metric for estimating the current climate forcing of natural mires

Authors:

Janne Rinne, Juha-Pekka Tuovinen and Annalea Lohila

Summary:

Commensuration of the radiative effects of different greenhouse gases (GHGs) is crucial for understanding the effects of land cover and ecosystem changes on the global climate. However, none of the current commensuration approaches are suitable for addressing the current climatic effect of mire ecosystems as compared to the situation in which such mires would not exist. The mire ecosystems have accumulated carbon for millennia, creating a negative perturbation to the atmospheric carbon dioxide content, but at the same time they emit methane into the atmosphere. Thus, the functioning of mires involves GHG fluxes with opposing effects on Earth’s radiative balance. Here, based on a simple radiative forcing (RF) model, we propose a new metric for commensuration of the effects of accumulated carbon and methane emission (ACME) on Earth’s energy balance. This ACME approach is applicable to natural mires with a significant part of their carbon accumulated more than 1000 years ago and requires relatively few input data. We demonstrate the feasibility of the ACME approach by applying it to a set of northern mires. The ACME-based RF estimate indicates that these mires have a cooling effect on the current climate, contrary to what a global warming potential-based calculation suggests, since the climatic effect is dominated by the sustained carbon accumulation. By applying the new metric with varying estimates of the total carbon storage and methane emission of northern mires, we estimate the current RF of these mires to range from −0.49 to −0.26 W m⁻².

The net ecosystem carbon balance (NECB) at catchment scales in the Arctic

Authors:

Efrén López-Blanco, Maria Väisänen, Elodie Salmon, Cheristy P. Jones, Niels M. Schmidt, Hannu Marttila, Annalea Lohila, Sari Juutinen, Johan Scheller, Torben R. Christensen

Summary:

The Net Ecosystem Carbon Balance (NECB) is a crucial metric for understanding integrated carbon dynamics in Arctic and boreal regions, which are vital to the global carbon cycle. These areas are associated with significant uncertainties and rapid climate change, potentially leading to unpredictable alterations in carbon dynamics. This mini-review examines key components of NECB, including carbon sequestration, methane emissions, lateral carbon transport, herbivore interactions, and disturbances, while integrating insights from recent permafrost region greenhouse gas budget syntheses. We emphasize the need for a holistic approach to quantify the NECB, incorporating all components and their uncertainties. The review highlights recent methodological advances in flux measurements, including improvements in eddy covariance and automatic chamber techniques, as well as progress in modeling approaches and data assimilation. Key research priorities are identified, such as improving the representation of inland waters in process-based models, expanding monitoring networks, and enhancing integration of long-term field observations with modeling approaches. These efforts are essential for accurately quantifying current and future greenhouse gas budgets in rapidly changing northern landscapes, ultimately informing more effective climate change mitigation strategies and ecosystem management practices. The review aligns with the goals of the Arctic Monitoring and Assessment Program (AMAP) and Conservation of Arctic Flora and Fauna (CAFF), providing important insights for policymakers, researchers, and stakeholders working to understand and protect these sensitive ecosystems.

Future land-use pattern projections and their differences within the ISIMIP3b framework

Authors:

Edna Johanna Molina Bacca, Miodrag Stevanović, Benjamin Leon Bodirsky, Jonathan Cornelis Doelman, Louise Parsons Chini, Jan Volkholz, Katja Frieler, Christopher Paul Oliver Reyer, George Hurtt, Florian Humpenöder, Kristine Karstens, Jens Heinke, Christoph Müller, Jan Philipp Dietrich, Hermann Lotze-Campen, Elke Stehfest, and Alexander Popp

Summary:

Land use is a key human driver affecting Earth’s biogeochemical cycles, hydrology, and biodiversity. Therefore, projecting future land use is crucial for global change impact analyses. This study compares harmonized land-use and management trends, analyzing uncertainties through a three-factor variance analysis involving socioeconomic–climate scenarios, land-use models, and climate models. The projected patterns are used as human-forcing inputs for the Intersectoral Impact Model Intercomparison Project phase 3b (ISIMIP3b) and multiple impact modeling teams. We employ two models (IMAGE and MAgPIE) to project future land use and management under three socioeconomic–climate scenarios (SSP1–RCP2.6, SSP3–RCP7.0, and SSP5–RCP8.5), driven by impact data like yields, water demand, and carbon stocks from updated climate projections of five global models, considering CO₂ fertilization effects. On the global level, there is strong agreement among land-use models on land-use trends in the SSP1–RCP2.6 scenario (low adaptation and mitigation challenges). However, significant differences exist in management-related variables, such as the area allocated for second-generation bioenergy crops. Uncertainty in land-use variables increases with higher spatial resolution, particularly concerning the locations where cropland and grassland shrinkage could occur under this scenario. In SSP5–RCP8.5 and SSP3–RCP7.0, differences among land-use models in global and regional trends are primarily associated with grassland area demand. Concerning the variance analysis, the selection of climate models minimally affects the variance in projections at different scales. However, the influence of the socioeconomic–climate scenarios, the land-use model, and interactions among the underlying factors on projected uncertainty varies for the different land-use and management variables. Our results highlight the need for more intercomparison exercises focusing on future spatially explicit projections to enhance understanding of the intricate interplay between human activities, climate, socioeconomic dynamics, land responses, and their associated uncertainties on the high-resolution level as models evolve. It also underscores the importance of region-specific strategies to balance agricultural productivity, environmental conservation, and sustainable resource use, emphasizing adaptive capacity building, improved land-use management, and targeted conservation efforts.

Controlled burning of peat before rewetting modifies soil chemistry and microbial dynamics to reduce short-term methane emissions

Authors:

Shihao Cui, Haonan Guo, Lorenzo Pugliese, Claudia Kalla Nielsen & Shubiao Wu

Summary:

Increased CH₄ emissions from rewetted organic soils can undermine the climate benefits of reduced CO₂ release. This is especially problematic in low-lying areas that tend to remain waterlogged and act as potential CH₄ hotspots. Here we test whether burning the soil surface before rewetting can reduce CH₄ emissions. Using laboratory experiments with soil cores collected from degraded farmland in Denmark, we found that rewetting organic soils following burning reduced CH₄ emissions by more than 95% over a 90-day period compared to rewetting alone. The reduction was likely associated with changed soil chemistry such as increased soil carbon stability and the decrease in methanogen abundance and activity. Our results suggest that targeted burning could help suppress short-term CH₄ emissions after rewetting. However, long-term field studies are needed to understand whether this effect persists and to assess potential ecological risks such as pollution runoff, before any broader field-scale implementation is considered.

Eddy-covariance fluxes of CO₂, CH₄ and N₂O in a drained peatland forest after clear-cutting

Authors:

Olli-Pekka Tikkasalo, Olli Peltola, Pavel Alekseychik, Juha Heikkinen, Samuli Launiainen, Aleksi Lehtonen, Qian Li, Eduardo Martínez-García, Mikko Peltoniemi, Petri Salovaara, Ville Tuominen, and Raisa Mäkipää

Summary:

Rotation forestry based on clear-cut harvesting, site preparation, planting and intermediate thinnings is currently the dominant management approach in Fennoscandia. However, understanding of the greenhouse gas (GHG) emissions following clear-cutting remains limited, particularly in drained peatland forests. In this study, we report eddy-covariance-based (EC-based) net emissions of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) from a fertile drained boreal peatland forest 1 year after wood harvest. Our results show that, at an annual scale, the site was a net CO₂ source. The CO₂ emissions dominate the total annual GHG balance (23.3 t CO_2 eq. ha⁻¹ yr⁻¹, 22.4–24.1 t CO_2 eq. ha⁻¹ yr⁻¹, depending on the EC gap-filling method; 82.0 % of the total), while the role of N₂O emissions (5.0 t CO_2 eq. ha⁻¹ yr⁻¹, 4.9–5.1 t CO_2 eq. ha⁻¹ yr⁻¹; 17.6 %) was also significant. The site was a weak CH₄ source (0.1 t CO_2 eq. ha⁻¹ yr⁻¹, 0.1–0.1 t CO_2 eq. ha⁻¹ yr⁻¹; 0.4 %). A statistical model was developed to estimate surface-type-specific CH₄ and N₂O emissions. The model was based on the air temperature, soil moisture and contribution of specific surface types within the EC flux footprint. The surface types were classified using unoccupied aerial vehicle (UAV) spectral imaging and machine learning. Based on the statistical models, the highest surface-type-specific CH₄ emissions occurred from plant-covered ditches and exposed peat, while the surfaces dominated by living trees, dead wood, litter and exposed peat were the main contributors to N₂O emissions. Our study provides new insights into how CH₄ and N₂O fluxes are affected by surface-type variation across clear-cutting areas in forested boreal peatlands. Our findings highlight the need to integrate surface-type-specific flux modelling, EC-based data and chamber-based flux measurements to comprehend the GHG emissions following clear-cutting and regeneration. The results also strengthen the accumulated evidence that recently clear-cut peatland forests are significant GHG sources.

Harnessing the Low-Hanging Fruits: Rewetting Unmanaged Marginal Organic Soils to Achieve Maximal Greenhouse Gas Reduction

Authors:

Haonan Guo, Shihao Cui , Claudia Kalla Nielsen, Lin Tang, Lorenzo Pugliese, Shubiao Wu

Summary:

Wetland methane responses to temperature and precipitation are studied in a boreal wetland-rich region in northern Europe using ecosystem process models. Six ecosystem models (JSBACH-HIMMELI, LPX-Bern, LPJ-GUESS, JULES, CLM4.5, and CLM5) are compared to multi-model means of ecosystem models and atmospheric inversions from the Global Carbon Project and upscaled eddy covariance flux results for their temperature and precipitation responses and seasonal cycles of the regional fluxes. Two models with contrasting response patterns, LPX-Bern and JSBACH-HIMMELI, are used as priors in atmospheric inversions with Carbon Tracker Europe–CH4 (CTE-CH4) in order to find out how the assimilation of atmospheric concentration data changes the flux estimates and how this alters the interpretation of the flux responses to temperature and precipitation. Inversion moves wetland emissions of both models towards co-limitation by temperature and precipitation. Between 2000 and 2018, periods of high temperature and/or high precipitation often resulted in increased emissions. However, the dry summer of 2018 did not result in increased emissions despite the high temperatures. The process models show strong temperature and strong precipitation responses for the region (51 %–91 % of the variance explained by both). The month with the highest emissions varies from May to September among the models. However, multi-model means, inversions, and upscaled eddy covariance flux observations agree on the month of maximum emissions and are co-limited by temperature and precipitation. The setup of different emission components (peatland emissions, mineral land fluxes) has an important role in building up the response patterns. Considering the significant differences among the models, it is essential to pay more attention to the regional representation of wet and dry mineral soils and periodic flooding which contribute to the seasonality and magnitude of methane fluxes. The realistic representation of temperature dependence of the peat soil fluxes is also important. Furthermore, it is important to use process-based descriptions for both mineral and peat soil fluxes to simulate the flux responses to climate drivers.

Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in Northern Europe

Authors: Tuula Aalto, Aki Tsuruta, Jarmo Mäkelä, Jurek Müller, Maria Tenkanen, Eleanor Burke, Sarah Chadburn, Yao Gao, Vilma Mannisenaho, Thomas Kleinen, Hanna Lee, Antti Leppänen, Tiina Markkanen, Stefano Materia, Paul A. Miller, Daniele Peano, Olli Peltola, Benjamin Poulter, Maarit Raivonen, Marielle Saunois, David Wårlind, and Sönke Zaehle

Summary:

Modelling alternative harvest effects on soil CO₂ and CH₄ fluxes from peatland forests

Authors: Xuefei Li , Tiina Markkanen, Mika Korkiakoski, Annalea Lohila, Antti Leppänen, Tuula Aalto, Mikko Peltoniemi, Raisa Mäkipää, Thomas Kleinen, Maarit Raivonen

Summary:

Healthy freshwater ecosystems can provide vital ecosystem services (ESs), and this capacity may be hampered due to water quality deterioration and climate change. In the currently available ES modeling tools, ecosystem processes are either absent or oversimplified, hindering the evaluation of impacts of restoration measures on ES provisioning. In this study, we propose an ES modeling tool that integrates lake physics, ecology and service provisioning into a holistic modeling framework. We applied this model to a Dutch quarry lake, to evaluate how nine ESs respond to technological-based (phosphorus (P) reduction) and nature-based measures (wetland restoration). As climate change might be affecting the future effectiveness of restoration efforts, we also studied the climate change impacts on the outcome of restoration measures and provisioning of ESs, using climate scenarios for the Netherlands in 2050. Our results indicate that both phosphorus reduction and wetland restoration mitigated eutrophication symptoms, resulting in increased oxygen concentrations and water transparency, and decreased phytoplankton biomass. Delivery of most ESs was improved, including swimming, P retention, and macrophyte habitat, whereas the ES provisioning that required a more productive system was impaired (sport fishing and bird watching). However, our modeling results suggested hampered effectiveness of restoration measures upon exposure to future climate conditions, which may require intensification of restoration efforts in the future to meet restoration targets. Importantly, ESs provisioning showed non-linear responses to increasing intensity of restoration measures, indicating that effectiveness of restoration measures does not necessarily increase proportionally. In conclusion, the ecosystem service modeling framework proposed in this study, provides a holistic evaluation of lake restoration measures on ecosystem services provisioning, and can contribute to development of climate-robust management strategies.

Process-based modeling for ecosystem service provisioning: Non-linear responses to restoration efforts in a quarry lake under climate change

Authors: Gabrielle R. Quadra, Sannimari Käärmelahti, Gijs van Dijk, Greta Gaudig, Matthias Krebs, Anja Prager, Adam H. W. Koks, Renske J. E. Vroom, Weier Liu, Ralph J. M. Temmink, Christian Fritz

Summary:

Unraveling Spatially Diverse and Interactive Regulatory Mechanisms of Wetland Methane Fluxes to Improve Emission Estimation

Authors: Haonan Guo, Shihao Cui, Claudia Kalla Nielsen, Johannes Wilhelmus, Maria Pullens, Chunjing Qiu, Shubiao Wu

Summary: Methane fluxes (FCH₄) vary significantly across wetland ecosystems due to complex mechanisms, challenging accurate estimations. The interactions among environmental drivers, while crucial in regulating FCH₄, have not been well understood. Here, the interactive effects of six environmental drivers on FCH₄ were first analyzed using 396,322 half-hourly measurements from 22 sites across various wetland types and climate zones. Results reveal that soil temperature, latent heat turbulent flux, and ecosystem respiration primarily exerted direct effects on FCH₄, while air temperature and gross primary productivity mainly exerted indirect effects by interacting with other drivers. Significant spatial variability in FCH₄ regulatory mechanisms was highlighted, with different drivers demonstrated varying direct, indirect, and total effects among sites. This spatial variability was then linked to site-specific annual-average air temperature (17.7%) and water table (9.0%) conditions, allowing the categorization of CH₄ sources into four groups with identified critical drivers. An improved estimation approach using a random forest model with three critical drivers was consequently proposed, offering accurate FCH₄ predictions with fewer input requirements. By explicitly accounting for environmental interactions and interpreting spatial variability, this study enhances our understanding of the mechanisms regulating CH₄ emissions, contributing to more efficient modeling and estimation of wetland FCH₄.

The effect of water table ﬂuctuation on 12 Sphagnum species during establishment: implications for peatland restoration and paludiculture

Authors: Gabrielle R. Quadra, Sannimari Käärmelahti, Gijs van Dijk, Greta Gaudig, Matthias Krebs, Anja Prager, Adam H. W. Koks , Renske J. E. Vroom, Weier Liu, Ralph J. M. Temmink, Christian Fritz

Summary: Sphagnum mosses are vital to bog ecosystems and are, therefore, target species for peatland restoration and paludiculture. Their establishment relies on consistent wet conditions and adequate nutrient supply. However, extreme climatic events, such as prolonged droughts, threaten Sphagnum establishment. To better understand the effects of water table ﬂuctuations on the establishment of different Sphagnum species, we conducted a ﬁeld experiment with stable and ﬂuctuating water table conditions.

After 1 year, we measured Sphagnum cover, lawn height (as a proxy for growth), carbon (C) accumulation, and nutrient stoichiometry of 12 species. Our results show that a stable water table facilitated Sphagnum growth during the establishment. Nitrogen (N) to potassium (K) and N to phosphorus (P) quotients were higher in the capitula biomass of Sphagnum in the ﬂuctuating water table treatment. We identiﬁed two clusters of Sphagnum species: cluster 1, characterized by a low N:K quotient and higher C accumulation—indicating strong establishment potential—included Sphagnum palustre, S. fallax, S. ﬁmbriatum, S. riparium, and S. denticulatum. In contrast, cluster 2 exhibited a higher N:K quotient and lower C accumulation—suggesting vulnerability to environmental changes during establishment—included S. fuscum, S. centrale, S. magellanicum, S. papillosum, S. rubellum, S. austinii, and S. squarrosum. Our results indicate that lawn species, particularly S. palustre, S. fallax, and S. denticulatum, are promising candidates for rapid Sphagnum establishment under wet and dry conditions. Even when exposed to water shortages, Sphagnum restoration and paludiculture can promote fast-track C accumulation.

Site-dependent carbon and greenhouse gas balances of five fen and bog soils after rewetting and establishment of Phalaris arundinacea paludiculture

Authors: Claudia Nielsen, Lars Elsgaard, Poul Erik Lærke

Summary: Peatlands cover 3 % of the Danish land area, but drainage of these areas contributes to approximately 25 % of the total agricultural greenhouse gas (GHG) emissions. Paludiculture, defined as agriculture on wet or rewetted peatlands, has been proposed as a strategy to mitigate GHG emissions while keeping up production. However, little is known about the net GHG effects during establishment and how it is influenced by soil biogeochemical conditions. In this study, we determined annual carbon balances of five Danish peatlands, three fens and two bogs, for the first year of cultivation with reed canary grass (RCG) with two annual cuts in a mesocosm set-up under controlled conditions. Biomass yields were highly variable, ranging between 0.8 and 7.4 t dry matter (DM) ha⁻¹ yr⁻¹, and significantly higher on fen peat soils. Ecosystem respiration (R_eco) fluxes of CO₂ were naturally highest from sites with high biomass establishment. Methane emissions were site-specific, ranging between 0.03 and 1.85 t CH₄ (CO₂eq ha⁻¹ yr⁻¹), and affected by biomass growth, as well as bulk density and the iron content within soil. Nitrous oxide fluxes were negligible, despite nitrogen (N) fertilisation with 200 kg N ha⁻¹ yr⁻¹. Driven by net primary production (NPP) we found that the fen sites were GHG sinks, with a global warming potential (GWP) of −1.3 to −11.5 t CO₂eq ha⁻¹ yr⁻¹ during the first year of rewetting and RCG establishment. The bogs remained sources of carbon (5.3 t CO₂eq ha⁻¹ yr⁻¹). Our results highlighted that the nutrient-rich Danish fen peatlands showed a potential for GHG mitigation by paludiculture under extensive agricultural management, while this was not the case for the bog sites due to poor biomass establishment. In conclusion, we found the highest GHG mitigation potential by rewetting and RCG paludiculture on nutrient-rich fen peatlands.

Food and land system transformations under different societal perspectives on sustainable development

Authors: Isabelle Weindl, Bjoern Soergel, Geanderson Ambrósio, Vassilis Daioglou, Jonathan Doelman, Felicitas Beier, Arthur Beusen, Benjamin Leon Bodirsky, Astrid Bos, Jan Philipp Dietrich, Florian Humpenöder, Patrick von Jeetze, Kristine Karstens, Sebastian Rauner, Elke Stehfest, Miodrag Stevanović, Willem-Jan van Zeist, Hermann Lotze-Campen, Detlef van Vuuren, Elmar Kriegler and Alexander Popp

Summary: The future of food and land systems is crucial for achieving multiple UN Sustainable Development Goals, given their essential role in providing adequate nutrition and their significant impact on Earth system processes. Despite widespread consensus on the need for transformation, discussed strategies vary widely, from technology-driven to sufficiency-focused approaches, emphasizing different agents of change and policy mixes. This study assesses the implications of a new generation of target-seeking scenarios incorporating such diverse sustainability perspectives. We apply two integrated assessment models to explore food and land futures under three whole-economy sustainable development pathways (SDPs): Economy-driven Innovation, Resilient Communities, and Managing the Global Commons. Our assessment shows that the SDPs align sufficient food supply with progress towards planetary integrity, halting biodiversity loss, mitigating adverse impacts from irrigation, and significantly reducing nitrogen pollution. While all SDPs comply with the Paris climate target, they diverge in the timing of climate mitigation efforts and focus on different greenhouse gases and emission sources. The Economy-driven Innovation pathway rapidly achieves net-negative CO₂ emissions from the land system, whereas the pathways Resilient Communities and Managing the Global Commons significantly decrease agricultural non-CO₂ emissions. Moreover, sustainability interventions attenuate trade-offs associated with narrowly focused mitigation scenarios and reduce reliance on carbon dioxide removal strategies like bioenergy with carbon capture and storage.

Shallow drainage of agricultural peatlands without land-use change: have your peat and eat it too - Frontiers in Environmental Science

Authors: T. S. Heuts, Q. van Giersbergen,R. Nouta, T. P. A. Nijman, R. C. H. Aben, O. van der Scheer, P G. M. Heuts, L. J. Skovsholt, G R. Quadra, A. J. P. Smolders,A. C. Fritz

Summary: Drainage for agricultural purposes is one of the main drivers of peatland degradation, leading to significant greenhouse gas (GHG) emissions, biodiversity loss, and soil eutrophication. This study explored whether three different water level management techniques (subsoil irrigation, furrow irrigation, and dynamic ditch water level regulation) could be implemented on dairy grasslands to yield increases in essential ecosystem services (vegetation diversity and soil biogeochemistry) without the need to change the current land use or intensity. We investigated vegetation diversity, soil biogeochemistry, and CO2 emission reduction in fourteen agricultural livestock pastures on drained peat soils in Friesland (Netherlands). Across all pastures, Shannon-Wiener diversity was below 1, and the species richness was below 5. The potential for CO₂ emission reduction remained small or even absent. In conclusion, our research suggests that incomplete rewetting (i.e., higher water tables while maintaining drainage) while continuing the current land use does neither effectively mitigate GHG emissions nor benefit vegetation diversity. Therefore, we conclude that combining WLM and reducing land-use intensity is essential to limit the degradation of peat soils and restore more biodiverse vegetation.

Wetland hydrological dynamics and methane emissions - Communications Earth & Environment

Authors: Shihao Cui, Pengfei Liu, Haonan Guo, Claudia Kalla Nielsen, Johannes Wilhelmus Maria Pullens, Qing Chen, Lorenzo Pugliese, Shubiao Wu

Summary: Wetlands are the largest and most uncertain biological source of atmospheric methane, with hydrological fluctuations exacerbating this uncertainty. Here we critically explore the complex relationship between hydrological fluctuations and methane emissions in wetlands by integrating observations from 31 FLUXNETwetlandsites with acomprehensiveliterature review. We present the prevalence and patterns of water table fluctuations and their contribution to uncertainty in methane fluxes. We also highlight key pathways through which these fluctuations affect methane production and emission, such as soil redox heterogeneity, changes in substrate availability and alternative electron acceptor pool, the contribution of different methane transport pathways, and the non-linear responses of community structure and activity of methanogens and methanotrophs to hydrological fluctuations. This review aims to improve the accuracy of wetland methane emission reports by carefully assessing biogeochemical kinetics under hydrological fluctuations.

Geobatteries in environmental biogeochemistry: Electron transfer and utilization - Environmental Science and Ecotechnology

Authors: Shihao Cui, Rui Wang, Qing Chen, Lorenzo Pugliese, Shubiao Wu

Summary: The efficiency of direct electron flow from electron donors to electron acceptors in redox reactions is significantly influenced by the spatial separation of these components. Geobatteries, a class of redoxactive substances naturally present in soilewater systems, act as electron reservoirs, reversibly donating, storing, and accepting electrons. This capability allows the temporal and spatial decoupling of redox half-reactions, providing a flexible electron transfer mechanism. In this review, we systematically examine the critical role of geobatteries in influencing electron transfer and utilization in environmental biogeochemical processes. Typical redox-active centers within geobatteries, such as quinone-like moieties, nitrogen- and sulfur-containing groups, and variable-valent metals, possess the potential to repeatedly charge and discharge. Various characterization techniques, ranging from qualitative methods like elemental analysis, imaging, and spectroscopy, to quantitative techniques such as chemical, spectroscopic, and electrochemical methods, have been developed to evaluate this reversible electron transfer capacity. Additionally, current research on the ecological and environmental significance of geobatteries extends beyond natural soilewater systems (e.g., soil carbon cycle) to engineered systems such as water treatment (e.g., nitrogen removal) and waste management (e.g., anaerobic digestion). Despite these advancements, challenges such as the complexity of environmental systems, difficulties in accurately quantifying electron exchange capacity, and scaling-up issues must be addressed to fully unlock their potential. This review underscores both the promise and challenges associated with geobatteries in responding to environmental issues, such as climate change and pollutant transformation.

To Harvest or not to Harvest: Management Intensity did not Affect Greenhouse Gas Balances of Phalaris Arundinacea Paludiculture - Wetlands

Authors: Claudia Kalla Nielsen, Weier Liu, Michael Koppelgaard, Poul Erik Laerke

Summary:The cultivation of flooding-tolerant grasses on wet or rewetted peatlands is a priority in climate change mitigation, balancing the trade-off between atmospheric decarbonisation and biomass production. However, effects of management intensities on greenhouse gas (GHG) emissions and the global warming potential (GWP) are widely unknown. This study assessed whether intensities of two and five annual harvest occurrences at fertilisation rates of 200 kg nitrogen ha−1 yr−1 affects GHG exchange dynamics compared to a ‘nature scenario’ with neither harvest nor fertilisation. Fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), using opaque and transparent chambers, were measured on a wet fen peatland with a mean water table depth of -10 cm below soil surface. Overall, no treatment effect was found on biomass yields and GHG emissions. Annual cumulative CH4 emissions were low, ranging between 0.3 and 0.5 t CO2-C eq ha−1 yr−1 . Contrary to this, emissions of N2O were high, ranging between 1.1 and 1.5 t CO2-C eq ha−1 yr−1 . For magnitudes of CH4 and N2O, soil moisture conditions and electrical peat properties were critical proxies. Atmospheric uptake of CO2 by net ecosystem exchange was higher for the treatments with management. However, this benefit was offset by the export of carbon in biomass compared to the treatment without management. In conclusion, the results highlighted a near-equal GWP in the range of 10.5–11.5 t CO2-C eq t ha−1 yr−1 for all treatments irrespectively of management. In a climate context, a restoration scenario but also intensive paludiculture practices were equal land-use options.

Active afforestation of drained peatlands is not a viable option under the EU Nature Restoration Law - Ambio

Authors: Gerald Jurasinski , Alexandra Barthelmes, Kenneth A. Byrne, Bogdan H. Chojnicki,
Jesper Riis Christiansen, Kris Decleer, Christian Fritz, Anke Beate Gu¨nther, Vytas Huth,
Hans Joosten, Radosław Juszczak, Sari Juutinen, A˚sa Kasimir, Leif Klemedtsson,
Franziska Koebsch, Wiktor Kotowski, Ain Kull, Mariusz Lamentowicz, Amelie Lindgren,
Richard Lindsay, Rita Linkevicˇiene, Annalea Lohila et. al

Summary: The EU Nature Restoration Law (NRL) is critical for the restoration of degraded ecosystems and active afforestation of degraded peatlands has been suggested as a restoration measure under the NRL. Here, we discuss the current state of scientific evidence on the climate mitigation effects of peatlands under forestry. Afforestation of drained peatlands without restoring their hydrology does not fully restore ecosystem functions. Evidence on long-term climate benefits is lacking and it is unclear whether CO2 sequestration of forest on drained peatland can offset the carbon loss from the peat over the long-term. While afforestation may offer short-term gains in certain cases, it compromises the sustainability of peatland carbon storage. Thus, active afforestation of drained peatlands is not a viable option for climate mitigation under the EU Nature Restoration Law and might even impede future rewetting/restoration efforts. Instead, restoring hydrological conditions through rewetting is crucial for effective peatland restoration.

Unraveling microbial processes involved in carbon and nitrogen cycling and greenhouse gas emissions in rewetted peatlands by molecular biology - Biogeochemistry

Authors: Emilie Gios, Erik Verbruggen, Joachim Audet, Rachel Burns, Klaus Butterbach‑Bahl, Mikk Espenberg, Christian Fritz, Stephan Glatzel, Gerald Jurasinski, Tuula Larmola, Ülo Mander, Claudia Nielsen, Andres F. Rodriguez, Clemens Scheer, Dominik Zak, Hanna M. Silvennoinen

Summary: Restoration of drained peatlands through rewetting has recently emerged as a prevailing strategy to mitigate excessive greenhouse gas emissions and re-establish the vital carbon sequestration capacity of peatlands. Rewetting can help to restore vegetation communities and biodiversity, while still allowing for extensive agricultural management such as paludiculture. Below ground processes governing carbon fluxes and greenhouse gas dynamics are mediated by a complex network of microbial communities and processes. Our understanding of this complexity and its multi-factorial controls in rewetted peatlands is limited. Here, we summarize the research regarding the role of soil microbial communities and functions in driving carbon and nutrient cycling in rewetted peatlands including the use of molecular biology techniques in understanding biogeochemical processes linked to greenhouse gas fluxes. We emphasize that rapidly advancing molecular biology approaches, such as high-throughput sequencing, are powerful tools helping to elucidate the dynamics of key biogeochemical processes when combined with isotope tracing and greenhouse gas measuring techniques. Insights gained from the gathered studies can help inform efficient monitoring practices for rewetted peatlands and the development of climate-smart restoration and management strategies.

Healing Peatlands to Protect Our Planet - Frontiers for Young Minds

Authors: Gabrielle R. Quadra, Sannimari Käärmelahti, Christian Fritz, Ralph J. M. Temmink

Summary: Peat is interesting; it is very wet and made from old plants and animals breaking down very slowly. Even though peatlands are just 3% of the land, they lock away 30% of Earth’s carbon. But sometimes people mess things up by draining the peatlands and digging up the peat, which releases carbon into the atmosphere and contributes to the warming of our planet. But do not worry; we can save the day! We can put water back in the peatlands to bring them back to life so they can lock carbon again. Sphagnum—the Latin name of a peat moss—is the hero here! This special moss can support peat formation and be used for gardening and growing food. Ready to help save peatlands and protect the planet? Keep reading!

A food system transformation can enhance global health, environmental conditions and social inclusions - Research Square

Authors: Benjamin Bodirsky, Felicitas Beier, Florian Humpenöder, Debbora Leip, Michael Crawford, David Chen, Patrick von Jeetze, Marco Springmann, et. al

Summary: The current global food system has detrimental outcomes for global health, environmental conditions and social inclusion. A coherent vision of a desirable food system can guide a sustainable food system transformation and help to structure political processes and private decisions by quantifying potential benefits, facilitating debates about co-benefits and trade-offs, and identifying key measures for desirable change. Such a transformation requires integrating measures targeting human diets, livelihoods, biosphere integrity, and agricultural management. Here, we apply a global food and land system modeling framework to quantify the impacts of 23 food system measures by 2050. Our multi-criteria assessment shows that a food system transformation can improve outcomes for health, the environment, social inclusion, and the economy. All individual measures come with trade-offs, particularly those targeting agricultural management, while few trade-offs and multiple co-benefits are linked to dietary change measures. By combining measures in packages, trade-offs can be reduced and co-benefits enhanced. We show that a sustainable food system also requires a transformation of the overall economy to stop global warming, reduce absolute poverty, and create alternative employment options. Within the context of a cross-sectoral sustainable development pathway, the food system transformation improves 14 of our 15 outcome indicators.

Temporally dynamic carbon dioxide and methane emission factors for rewetted peatlands - Communications Earth & Environment

Authors:Aram Kalhori, Christian Wille, Pia Gottschalk, Zhan Li, Josh Hashemi, Karl Kemper, Torsten Sachs

Summary: Rewetting drained peatlands is recognized as a leading and effective natural solution to curb greenhouse gas emissions. However, rewetting creates novel ecosystems whose emission behaviors are not adequately captured by currently used emission factors. These emission factors are applied immediately after rewetting, thus do not reflect the temporal dynamics of greenhouse gas emissions during the period wherein there is a transition to a rewetted steady-state. Here, we provide long-term data showing a mismatch between actual emissions and default emission factors and revealing the temporal patterns of annual carbon dioxide and methane fluxes in a rewetted peatland site in northeastern Germany. We show that site-level annual emissions of carbon dioxide and methane approach the IPCC default emission factors and those suggested for the German national inventory report only between 13 to 16 years after rewetting. Over the entire study period, we observed a source-to-sink transition of annual carbon dioxide fluxes with a decreasing trend of −0.36 t CO2-C ha−1 yr−1 and a decrease in annual methane emissions of −23.6 kg CH4 ha−1 yr−1. Our results indicate that emission factors should represent the temporally dynamic nature of peatlands post-rewetting and consider the effect of site characteristics to better estimate associated annual emissions.

Topsoil removal for Sphagnum establishment on rewetted agricultural bogs - Biogeochemistry

Authors: Sannimari A. Käärmelahti, Christian Fritz, Gabrielle R. Quadra, Maider Erize Gardoki, Greta Gaudig, Matthias Krebs, Ralph J. M. Temmink

Summary: Rewetting drained agricultural peatlands aids in restoring their original ecosystem functions, including carbon storage and sustaining unique biodiversity. 30–60 cm of topsoil removal (TSR) before rewetting for Sphagnum establishment is a common practice to reduce nutrient concentrations and greenhouse gas emissions, and increase water conductivity. However, the topsoil is carbon-dense and preservation in situ would be favorable from a climate-mitigation perspective. The effect of reduced TSR on Sphagnum establishment and nutrient dynamics on degraded and rewetted raised bogs remains to be elucidated. We conducted a two-year field experiment under Sphagnum paludiculture management with three TSR depths: no-removal (TSR0), 5–10 cm (TSR5), and 30 cm (TSR30) removal. We tested the effects of TSR on Sphagnum establishment and performance, nutrient dynamics, and hotspot methane emissions. After two years, TSR5 produced similar Sphagnum biomass as TSR30, while vascular plant biomass was highest in TSR0. All capitula nitrogen (N > 12 mg/g) indicated N-saturation. Phosphorus (P) was not limiting (N/P < 30), but a potential potassium (K) limitation was observed in year one (N/K > 3). In TSR0, ammonium concentrations were > 150 µmol/l in year one, but decreased by 80% in year two. P-concentrations remained high (c. 100 µmol/l) at TSR0 and TSR5, and remained low at TSR30. TSR30 and TSR5 reduced hotspot methane emissions relative to TSR0. We conclude that all TSR practices have their own advantages and disadvantages with respect to Sphagnum growth, nutrient availability and vegetation development. While TSR5 may be the most suitable for paludiculture, its applicability for restoration purposes remains to be elucidated. Setting prioritized targets when selecting the optimal TSR with peatland rewetting is pivotal.

Drainage ditches are year-round greenhouse gas hotlines in temperate peat landscapes - Freshwater Biology

Authors: Lisanne Hendriks, Stefan Weideveld, Christian Fritz, Tatiana Stepina, Ralf C. H. Aben, Ngum E. Fung, Sarian Kosten

Summary: Greenhouse gas (GHG) emissions from drained peatlands have been studied extensively. Considerably less attention has been paid to the emissions from the ditches used to drain peatlands. High within-ditch GHG production and lateral inflow of GHGs may lead to ditches emitting considerable amounts of GHGs on the landscape scale.We quantified annual emissions of ebullitive and diffusive methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) in 10 drainage ditches in intensively used temperate peatlands used for dairy farming, in The Netherlands. Additionally, we assessed water and sediment quality to determine proxies for emissions via the two emission pathways.The mean annual emissions from the studied ditches varied between 3.57 and 60.1 g CO2-eq. m−2 day−1 (based on a global warming potential over a 100-year timeframe), where CO2 contributed on average 43% (ranging between 1.9 and 22.0 g CO2 m−2 day−1) and diffusive CH4 contributed 16% (0.1–16.5 g CO2-eq. m−2 day−1) to the total GHG emission. Ebullition of CH4 made up nearly half of the total GHG emission (40%, 1.3–40.9 g CO2-eq. m−2 day−1). N2O emissions were mostly low. CO2 emissions were higher in winter months, while CH4 ebullition was higher during spring and summer. Diffusive CH4 emissions did not show a seasonal pattern.The mean emission factor, the estimate of average emissions per unit area (EF), for CH4 was 2144 kg CH4 ha−1 year−1, which is two times higher than the tier 1 EF reported by the IPCC (with underrepresented ebullition data), underlining the high variability of ditch emissions.Ditch emissions were also higher than the EF used for the surrounding drained peatlands indicating that ditch emissions can be important on the landscape scale and should be considered to be included in national greenhouse gas reporting.

Wetscapes: Restoring and maintaining peatland landscapes for sustainable futures - Ambio

Authors: Ralph J. M. Temmink , Bjorn J. M. Robroek, Gijs van Dijk,
Adam H. W. Koks, Sannimari A. Käärmelahti, Alexandra Barthelmes,
Martin J. Wassen, Rafael Ziegler, Magdalena N. Steele, Wim Giesen,
Hans Joosten, Christian Fritz, Leon P. M. Lamers, Alfons J. P. Smolders

Summary: Peatlands are among the world’s most carbondense ecosystems and hotspots of carbon storage. Although peatland drainage causes strong carbon emissions, land subsidence, fires and biodiversity loss, drainage-based agriculture and forestry on peatland is still expanding on a global scale. To maintain and restore their vital carbon sequestration and storage function and to reach the goals of the Paris Agreement, rewetting and restoration of all drained and degraded peatlands is urgently required. However, socio-economic conditions and hydrological constraints hitherto prevent rewetting and restoration on large scale, which calls for rethinking landscape use. We here argue that creating integrated wetscapes (wet peatland landscapes), including nature preserve cores, buffer zones and paludiculture areas (for wet productive land use), will enable sustainable and complementary land-use functions on the landscape level. As such, transforming landscapes into wetscapes presents an inevitable, novel, ecologically and socio-economically sound alternative for drainagebased peatland use.

Removing 10 cm of degraded peat mitigates unwanted efects of peatland rewetting: a mesocosm study - Radboud University Repository

Authors: Gabrielle R. Quadra, Coline C.F. Boonman, Renske J.E. Vroom, Alfons J.P. Smolders, Jeroen J.M. Geurts, Ralf C.H. Aben, Ralph J.M. Temmink, Stefan T.J. Weideveld, Christian Fritz

Summary: Topsoil removal (TSR) is a management option performed before rewetting drained agricultural peatlands to reduce greenhouse gas (GHG) emissions and remove nutrients. Currently, its common practice to remove 30 to 60 cm of topsoil, which is labor-intensive, costly, and highly disruptive. However, optimal TSR depth for mitigating carbon emissions from rewetted peat soils has neither been determined nor linked to soil biogeochemical factors driving carbon emissions. We performed two mesocosm experiments to address this. In experiment 1, we removed the topsoil of two contrasting drained peat soils before rewetting (i.e., extensively managed, acid peat and intensively managed, near-neutral peat) with a 5 cm interval up to 25 cm TSR. In experiment 2, we combined TSR with the presence and absence of Typha latifolia on intensively managed, near-neutral peat soil. The experiments ran for 22 and three months, respectively, in which we measured carbon dioxide (CO2) and methane (CH4) emissions and porewater chemistry. Our experiments reveal that (i) 5 cm TSR greatly reduced CH4 and CO2 emissions irrespective of peat nutrient status during the 22-month experiment, and (ii) the presence of T. latifolia further reduced CH4 emissions during the 3-month experiment. Specifically, CH4 emissions were six to 10-times lower with 5 cm TSR compared to 0 cm TSR. Peak CH4 emissions occurred after three months with 0 cm TSR and strongly decreased thereafter. Random forest analyses highlighted that variation in CH4 emissions could mainly be explained by cumulative root biomass and porewater alkalinity. Furthermore, 5 cm TSR reduced porewater values of pH, alkalinity, CH4, and ammonium. The effectiveness of TSR in preventing the build-up of phosphorus, iron, and sulfur in porewater was site-specific. Our results show that only 5 to 10 cm TSR may already effectively prevent the adverse effects of rewetting former agriculturally peatlands by reducing undesirable CH4 emissions and avoiding nutrient release. Further, we argue that target setting and site-specific assessments are crucial to optimize the amount of TSR to reduce carbon emissions while minimizing disturbance and costs.

Soil greenhouse gas emissions from drained and rewetted agricultural bare peat mesocosms are linked to geochemistry - Science of the Total Environment

Authors: C. K. Nielsen, L. Elsgaard, U. Jørgensen, P. E. Lærke

Summary: In view of climate considerations regarding the management of peatlands, there is a need to assess whether rewetting can mitigate greenhouse gas (GHG) emissions, and notably how site-specific soil-geochemistry will influence differences in emission magnitudes. However, there are inconsistent results regarding the correlation of soil properties with heterotrophic respiration (R_h) of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) from bare peat. In this study, we determined 1) soil-, and site-specific geochemical components as drivers for emissions from R_h on five Danish fens and bogs, and 2) emission magnitudes under drained and rewetted conditions. For this, a mesocosm experiment was performed under equal exposure to climatic conditions and water table depths controlled to either -40 cm, or -5 cm. For the drained soils, we found that annual cumulative emissions, accounting for all three gases, were dominated by CO₂, contributing with, on average, 99 % to a varying global warming potential (GWP) of 12.2–16.9 t CO₂eq ha⁻¹ yr⁻¹. Rewetting lowered annual cumulative emissions from R_h by 3.2–5.1 t CO₂eq ha⁻¹ yr⁻¹ for fens and bogs, respectively, despite a high variability of site-specific CH₄ emissions, contributing with 0.3–3.4 t CO₂ ha⁻¹ yr⁻¹ to the GWP. Overall, analyses using generalized additive models (GAM) showed that emission magnitudes were well explained by geochemical variables. Under drained conditions, significant soil-specific predictor variables for CO₂ flux magnitudes were pH, phosphorus (P), and the soil substrate’s relative water holding capacity (WHC). When rewetted, CO₂ and CH₄ emissions from R_h were affected by pH, WHC, as well as contents of P, total carbon and nitrogen. In conclusion, our results found the highest GHG reduction on fen peatlands, further highlighting that peat nutrient status and acidity, and the potential availability of alternative electron acceptors, might be used as proxies for prioritising peatland areas for GHG mitigation efforts by rewetting.

Trading wood for water and carbon in peatland forests? Rewetting is worth more than wood production - Journal of Environmental Management

Authors: Evaldas Makrickas, Michael Manton, Per Angelstam, Mateusz Grygoruk

Summary: While traditional forest management systems aim at maximizing timber production, sustainable forest management focuses on the multiple benefits of entire forest landscapes. The latter is now at the top of policy agendas. This calls for learning through evaluation to support the implementation of policies aiming towards multi-functional forest landscapes. The aim of this study is to quantify the economic trade-offs among natural, current, and re-wetted peatland forests using seven indicators, viz. drainage maintenance, rewetting, water retention, wood production, and three types of carbon sequestration as economic indicators. We discuss ways to adapt to and mitigate effect of forest draining on climate change toward securing multi-functional forest landscapes. The cost benefit analysis showed that in a potential natural state, Lithuania’s peatland forests would deliver an economic benefit of ∼€176.1 million annually. In contrast, compared to natural peatland forests, the drainage of peatland forests for wood production has caused a loss of ∼€309 million annually. In comparison, peatland forest rewetting is estimated to increase the economic value by ∼€170 million annually. This study shows that satisfying different ecosystem services is a balancing act, and that a focus on wood production has resulted in net losses when foregone values of water storage and carbon sequestration are considered. Valuation of different sets of ecosystems service benefits and disservices must be assessed, and can be used as a tool towards creating, implementing and monitoring consequences of policies on both sustainability and biodiversity.

Restoring organic matter, carbon and nutrient accumulation in degraded peatlands: 10 years Sphagnum paludiculture

Authors: Ralph J. M. Temmink, Renske J. E. Vroom, Gijs van Dijk, Sannimari A. Käärmelahti, Adam H. W. Koks, Hans Joosten, Matthias Krebs, Greta Gaudig, Kristina Brust, Leon P. M. Lamers, Alfons J. P. Smolders, Christian Fritz

Summary: Drained peatlands emit large amounts of greenhouse gases and cause downstream nutrient pollution. Rewetting aids in restoring carbon storage and sustaining unique biodiversity. However, rewetting for nature restoration is socio-economically not always feasible. Cultivation of Sphagnum biomass after rewetting allows agricultural production. In the short term, Sphagnum paludiculture is productive without fertilization but it remains unclear whether it sustains its functionality in the longer-term. We studied nutrient dynamics, organic matter build-up, and carbon and nutrient accumulation at a 16-ha Sphagnum paludiculture area in NW-Germany. Site preparation included topsoil removal and inoculation with Sphagnum and it was rewetted fve and ten years ago and managed with mowing, irrigation, and ditch cleaning. The unfertilized sites were irrigated with (compared to bog conditions) nutrient-rich surface water and exposed to atmospheric nitrogen deposition of 21 kg N/ha/yr. Our data reveal that ten years of Sphagnum growth resulted in a new 30 cm thick organic layer, sequestering 2,600 kg carbon, 56 kg nitrogen, 3.2 kg phosphorus, and 9.0 kg potassium per ha/yr. Porewater nutrient concentrations were low and remained stable over time in the top layer, while ammonium concentrations decreased from 400–700 to 0–50 µmol/L in the peat profle over 10 years. Hydro-climatic fuctuations most likely caused the variation in ammonium in the top layer. We conclude that Sphagnum paludiculture enables rapid carbon and nutrient accumulation without active fertilization provided the biomass is not harvested, and provides perspective for bog restoration on agricultural peatlands. Large-scale application of Sphagnum paludiculture may mitigate environmental issues of unsustainable peatland-use.

Production in peatlands: Comparing ecosystem services of different land use options following conventional farming - Science of the Total Environment

Authors: Weier Liu, Christian Fritz, Jasper van Belle, Sanderine Nonhebel

Summary: Majority of Dutch peatlands are drained and used intensively as grasslands for dairy farming. This delivers high productivity but causes severe damage to ecosystem services supply. Peatland rewetting is the best way to reverse the damage, but high water levels do not fit with intensive dairy production. Paludiculture, defined as crop production under wet conditions, provides viable land use alternatives. However, performance of paludiculture is rarely compared to drainage-based agriculture. Here, we compared the performances of six land use options on peatland following a gradient of low, medium, and high water levels, including conventional and organic drainage-based dairy farming, low-input grasslands for grazing and mowing, and high-input paludiculture with reed and Sphagnum cultivation. Results showed that drainage-based dairy farming systems support high provisioning services but low regulation and maintenance services. Organic farming provides higher climate and nutrient regulation services than its conventional counterpart, but limited overall improvement due to the persistent drainage. Low-intensity grassland and paludiculture systems have high regulation and maintenance services value, but do not supply biomass provisioning comparable to the drainage-based systems. Without capitalizing the co-benefits of regulation and maintenance services, and accounting for the societal costs from ecosystem disservices including greenhouse gas emission and nitrogen pollution, it is not likely that the farmers will be incentivized to change the current farming system towards the wetter alternatives. Sustainable use of peatlands urges fundamental changes in land and water management along with the financial and policy support required.

Nutrient dynamics of 12 Sphagnum species during establishment on a rewetted bog - Plant Biology

Authors: S. A. K ̈äärmelahti, R. J. M. Temmink, G. van Dijk, A. Prager, M. Kohl, G. Gaudig, A. H. W. Koks, W. Liu, R. J. E. Vroom, K. Gerwing, C. J. H. Peters, M. Krebs, C. Fritz

Summary: Peatland degradation through drainage and peat extraction have detrimental environmental and societal consequences. Rewetting is an option to restore lost ecosystem functions, such as carbon storage, biodiversity and nutrient sequestration. Peat mosses (Sphagnum) are the most important peat-forming species in bogs. Most Sphagnum species occur in nutrient-poor habitats; however, high growth rates have been reported in artificial nutrient-rich conditions with optimal water supply. Here, we demonstrate the differences in nutrient dynamics of 12 Sphagnum species during their establishment in a 1-year field experiment at a Sphagnum paludiculture area in Germany. Our study shows that slower-growing species (S. papillosum, S. magellancium, S. fuscum, S. rubellum, S. austinii; often forming hummocks) displayed signs of nutrient imbalance. These species accumulated higher amounts of N, P, K and Ca in their capitula, and had an elevated stem N:K quotient (>3). Additionally, this group sequestered less C and K per m2 than the fast and medium-growing species (S. denticulatum, S. fallax, S. riparium, S. fimbriatum, S. squarrosum, S. palustre, S. centrale). We conclude that nutrient dynamics and carbon/nutrient sequestration rates are species-specific. For bog restoration, generating ecosystem services or choosing suitable donor material for Sphagnum paludiculture, it is crucial to consider their compatibility with prevailing environmental conditions.

Governing high-integrity nature markets - EarthArxiv

Authors: Mark S. Reed, Julia M. McCarthy, Eric A. Jensen, Hannah Rudman

Summary: There is growing interest in the potential for ecosystem markets to facilitate climate and nature recovery, but there are concerns that poorly designed and operated markets may be used in corporate “greenwashing” and lead to negative unintended consequences for nature and local communities.

This paper:
1. Provides an overview of compliance and voluntary carbon and other ecosystem markets and systematically analyses relevant market actors in the UK, a country with well-developed and rapidly proliferating domestic markets that is actively seeking to increase their integrity;
2. Conducts a comparative analysis of existing national and international principles and synthesises a list of 14 core principles pertaining to the governance, measurement, reporting and verification, and wider benefits of high-integrity ecosystem markets; and
3. Develops an ecosystem markets governance hierarchy, showing the various policy, governance and market mechanisms and infrastructure that are being explored to implement the proposed principles in the UK.

Taken together, the core market principles and governance hierarchy could be used to ensure the development of high-integrity ecosystem markets across the UK and internationally, as national governments around the world attempt to responsibly build and scale these markets.

Ratio vegetation indices have the potential to predict extractable protein yields in green protein paludiculture - Mires and Peat

Authors: Claudia K. Nielsen, Lene Stødkilde, Uffe Jørgensen, Poul Erik Lærke

Summary: Paludiculture can be a tool to incentivise rewetting of agricultural peatlands with the option for biomass utilisation in green protein biorefineries. However, the economic feasibility for green protein paludiculture depends on product maximisation. This study explored the potential of a ratio vegetation index (RVI) model, with inclusion of climatic factors relevant for biomass growth, to predict crude protein (CP) contents in green protein precipitates from biorefining Phalaris arundinacea and Festuca arundinacea cultivated under different management intensities on a wet fen. Assessing yields for two years of cultivation, we found that timing of harvest was a key variable for CP extractability using the biorefinery technique. Biomass and protein yields were similar between management treatments and years, but extractability was enhanced in the dryer of the two years. This study highlighted the potential of an RVI model to predict, under varying climatic conditions, CP contents in the protein precipitate with good model performance (R2 = 0.64, NRMSE = 0.23) and accuracy. In 92 % of occurrences, the model was able to predict statistically similar CP contents compared to measured CP in the protein product, with an average deviation between measured and predicted annual values of 1.7 % across species and management intensities. The findings highlight an option for maximising the overall efficiency of green protein paludiculture by determining the optimal timing of harvest, thereby demonstrating an economic potential to incentivise paludiculture farming.

Local Calibration of TDR Measurements for Determining Water and Organic Carbon Contents of Peaty Soils - Soil Systems

Authors: Claudia Kalla Nielson and Anton Gårde Thomsen

Summary: Time domain reflectometry (TDR) measurements of the volumetric water content (θ) of soils are based on the dielectric permittivity (ε), relating ε to θ, using an empirical calibration function. Accurate determination of θ for peaty soils is vital but complicated by the complexity of organic soils and the lack of a general calibration model. Site-specific calibration models were developed to determine θ from TDR measurements for a heterogenous peatland across gradients of peat decomposition and organic carbon (OC) content; derived by soil organic matter conversion. The possibility of predicting OC contents based on the corrected θ (θ_cor); ε; electrical impedance (Ζ); and a categorical predictor variable was explored. The application of plot-specific and local area calibration models resulted in similar results. Compared to common calibrations, the threshold for accurate determination of θ was at ε = 5; with higher ε underestimating θ by up to 25%. Including the von Post degree of peat humification as a bioindicator, the OC content could be modelled across the area and the full range of θ with an accuracy of ±1.2% for 496 measurements. In conclusion, a strong indication was found for determining OC in peatlands in situ using TDR and a site-specific calibration model for θ together with indices of peat decomposition.

Wetland plant development overrides nitrogen effects on initial methane emissions after peat rewetting - Aquatic Botany

Authors: Coline C.F. Boonman, Tom S. Heuts, Renske J.E.Vroom, Jeroen J.M.Geurts, Christian Fritz

Summary: Nitrogen often stimulates methane production and its release in aquatic ecosystem containing labile carbon. In this experimental work we could show that wetland plants/paludiculture crops efficiently take up nitrogen and showed an overall mitigating effect on methane emissions. Soil biogeochemistry and land-use history was of lesser importance for the 2 soils included in this study. A nice add on of this study is that mesocosm methane fluxes match very well with hectare scale fluxes of similar wetlands (after rewetting). This is extra motivation to conduct mesocosm studies testing methane mitigation techniques that can be applied on the field scale (around the globe).

Database

WET HORIZONS has created a publicly available database of Ecosystem Services from European wetlands for trade-off quantifications.

This database contains data on several ecosystem services from studies across Europe. We have for each entry tried to include wetland type, coordinates, and auxiliary information for the given site, however users should have in mind that information gaps do occur. Furthermore, please have in mind that the database is not an exhaustive list of studies of European wetlands and should not be treated as such.

The database has columns grouped in categories starting with site description/information, followed by auxiliary information and lastly, ecosystem services. Each row represents a data entry.

Summaries of key Ecosystem Services from different types of wetlands and different restoration status can be procured in our easy-to-use dynamic web-application at https://louisskovsholt.shinyapps.io/ES_summaryapp/

The entire database is free to access and can be found via the link below.

If you have data you would like to add to the database or if you have any questions or comments, please contact Louis Skovsholt (ljs@bio.au.dk)

Dataset Publications

Within the WET HORIZONS project partners have created a collection of datasets. These publications are dedicated solely to documenting datasets. All datasets are openly available and free to access via Zenodo.

Master Dataset for Wetlands GHG Emission Factors

Authors: Kalhori, Aram; Gottschalk, Pia; Artz, Rebekka; Nielsen, Claudia; Juutinen, Sari; Heuts, Tom; Chapman, Jack

Summary: This dataset contains a harmonized master dataset for annual values of GHG Emission Factors and other anicillary parameters for different wet/peatland categories. It contains data from both European and non-European countries categorized by climate zones

Temporally and Spatially Stratified GHG Emission Factors for European Restored Peatlands

Authors: Kalhori, Aram; Gottschalk, Pia; Artz, Rebekka

Summary: The dataset contains annual values of GHG flux and metereological data for selected restored peatland sites within WET HORIZONS catchment areas. It includes both observation data and modelled data to derive spatio-temporally stratified emission factors in support of the WET HORIZONS objectives (specifically Task 2.3, WP2).

TempoSatellite Imagery Dataset (SPOT 6/7) – Task 2.3 Geospatial Data

Authors: Kalhori, Aram; Dutta, Ashish; Juutinen, Sari; Lotz, Christoph; Artz, Rebekka

Summary: The dataset contains geospatial datasets of selected European restored peatland areas, classified by land surface types. These datasets are used to derive spatio-temporally stratified emission factors in support of the WET HORIZONS objectives (specifically Task 2.3, WP2)

Compilation of mean monthly water table depth data (2015-2023) and linkages to further published sources of water table data, from European peatlands

Authors: Artz, Rebekka; Donaldson-Selby, Gillian; Smart, Catherine; Lohila, Annalea; Nielsen, Claudia; Grygoruk, Mateusz; Heuts, Tom; Fritz, Christian; Kalhori, Aram; Wu, Shubiao; Wilson, David

Summary: This dataset (WH_D1_4_meanmonthly.csv) contains mean monthly water table depth data for 211 point locations, for which the data were originally captured at a higher temporal resolution and were additionally clipped to the temporal window (2015 onwards) of the available Earth Observations in the Sentinel-1 and Sentinel-2 archive. Links to higher resolution/longer time series of these source data, where these are already in the public domain, have been identified in the data submission in case future data users require more detailed water table datasets.Information on site co-ordinates, data period, condition class, and other details, are provided in the associated metadata file (WH_D1_4_metadata.csv). Further links to 165 additional water table dynamics data have been provided for future users, but were not summarised as monthly means in this data submission in case the source data are updated in future. Please refer to the README file for methodological details and important disclaimers.