Forested area has decreased while agricultural area and degraded lands have expanded in the Indonesian peatlands of Sumatra and Kalimantan over the past few decades. The expansion of agricultural lands followed by construction of drainage (canal) infrastructure affects peatland hydrology and fire risk. This study examined how drainage density affects fire occurrence (hotspot density) using the Visible Infrared Imaging Radiometer Suite dataset in the Indonesian peatlands of Sumatra and Kalimantan across a range of climatic conditions and land cover types. During 2013-2017, our study shows a greater hotspot density in peatlands with canals compared to undrained peatlands. Largest differences are found in forest by a factor of 13.3, followed by degraded land (7.6), cropland (5) and plantation (2.6) during the ENSO-neutral year of 2013. Hotspot density in low to moderately drained peatlands increases with drainage density with high correlation (r value 0.97, 0.96, 0.94, and 0.67 in forests, degraded lands, croplands and plantations respectively) in 2013. However, as El Niño commenced, the impact of drainage density on hotspot density weakened. Fires were widespread in undrained peatlands especially in the prolonged drought of the strong El Niño in 2015. In highly drained peatlands where plantations dominated, fewer fires occurred than on moderately drained peatlands, which could be explained by various factors including management practices and peat loss. A multiple regression model, incorporating factors of ENSO status, land cover types and drainage density explains 67% of the variability in hotspot density. Our results support the strategy of fire control and peat restoration, especially in unmanaged degraded peatlands.

How to cite: Salmayenti, R., Baird, A., Holden, J., and Spracklen, D.: The combined effect of drainage density, land cover, and ENSO status on fire occurrence in tropical peatlands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14921, https://doi.org/10.5194/egusphere-egu25-14921, 2025.

Peatlands are vital carbon stores but risk turning into carbon sources due to anthropogenic disturbance. In Southeast Asia, an estimated 65% of tropical peatlands have been drained, primarily for agriculture and plantation development. This drainage results in drying, subsidence, and oxidation of the peat, leading to substantial CO₂ emissions stemming from the belowground biomass. Quantifying carbon emissions from peatlands in this region is therefore crucial and growing in importance for peat Measurement, Reporting, and Verification (MRV). However, measurements remain sparse due to the vast, swampy, densely vegetated, and often inaccessible nature of these tropical landscapes. By measuring peat motion, which is a proxy for peat CO₂ emissions, L-band Interferometric Synthetic Aperture Radar (InSAR) offers a cost-effective monitoring solution with the ability to penetrate vegetation and cover large areas at millimeter-scale precision. Despite its potential, the accuracy of L-band InSAR has not been rigorously validated in Southeast Asia and results can vary significantly depending on the InSAR processing strategies taken.

Here, we address this gap by using a unique combination of L-band ALOS-2 InSAR and high-accuracy, high-rate ground truth data from peat cameras to assess the InSAR accuracy for measuring peat motion. We use 5-year long ground measurements from 8 peat cameras distributed across oil palm plantations, croplands, scrublands, and forests in Central Kalimantan, Indonesia, to provide unprecedented evaluation of the accuracy of InSAR both temporally and spatially. We also mitigate major noise sources in ALOS-2 InSAR time series of ground motion stemming from the ionosphere, troposphere, and closure phase bias to improve the InSAR accuracy.

Our results demonstrate consistency of InSAR with the long-term velocities of peat motion from ground truth data across all sites with a mean RMSE of < 5 mm/year. We also show high accuracy of InSAR (RMSE ~1.6 cm and Pearson’s correlation coefficient ~0.7) in detecting sub-annual fluctuations of peat displacements over plantations and croplands, and poorer performance over some scrublands and forests but that can be identified based on the InSAR coherence. The 5-year span of the InSAR and peat camera datasets also reveal subsidence trends driven by drainage and accelerated during El Niño events. These results show the suitability of L-band for both multi-annual and sub-annual monitoring of peat motion in the tropics. In addition, these findings demonstrate that L-band InSAR can be scaled up to provide regional to global coverage, especially with the advent of new and upcoming L-band satellites (e.g. ALOS-4 and NISAR). Frequent data acquisitions and accurate data processing and analysis are essential for MRV of peat carbon. Without reliable data, verifying carbon credits and restoration efforts becomes impossible, undermining market credibility and effective mitigation of climate change impact. This study thus validates InSAR as a cost-effective and scalable tool and contributes to the robust assessment of ongoing climate action.

How to cite: Tay, C., Jovani-Sancho, A. J., Yulianti, L., Evans, C., Callaghan, N., Jaya, A., Salman, R., Zheng, Y., Susilo, S., Dohong, S., and Yun, S.-H.: Validating L-Band InSAR for Tropical Peat Motion Monitoring: A Transformative Approach for Peat Measurement, Reporting, and Verification, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8505, https://doi.org/10.5194/egusphere-egu25-8505, 2025.

In tropical countries like Indonesia, forest fires are common natural or human-induced disasters that occur throughout the Southeast Asian region all year around. It’s also known for its rich biodiversity and extensive peatlands, which are particularly vulnerable due to circumstances and risk factors. Thus, the research aims to shed light on forest fire susceptibility mapping and assessing high-risk zones based on land use, vegetation type, and climatic factors. This study utilized remote sensing through Google Earth Engine (GEE) and Geographic Information Systems (GIS) to evaluate forest fire risk in Sumatra, Indonesia, a region facing challenges such as rapid palm oil plantation development, timber concessions, and active peatland fires. Tropical rainforests, peatlands, and diverse ecosystems characterize Sumatra. The region is often affected by natural forest fires (e.g., El Niño events) and human-induced activities (e.g., illegal land clearing for plantation purposes). Forest fire locations in the study area were identified using historical hotspot data from 2014 to 2022. Fire risk assessments are typically generated using spectral indices to classify the spatial distribution of damage caused by fires; first, forest fire susceptibility through a combined index calculated by adding classified fire risk, forest loss index, normalized slope, aspect, temperature, and relative humidity. This index indicates potential fire risk and demonstrates how to integrate various geospatial datasets, such as vegetation indices, topography, and climate data, within GEE to assess forest fire risk. Then, we evaluated the feasibility of using remote sensing data to identify fire causes by validating forest fire occurrence factors. This study demonstrates how detailed risk assessment provides an effective method of managing forest fires in Riau Province, Sumatra, Indonesia, which can contribute to reducing the frequency and severity of fires, and improve sustainable forest management and governance.

How to cite: Agustiyara, A. and Székely, B.: Forest fire susceptibility and risk mapping assessment in Sumatra, Indonesia by remotely sensing data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6079, https://doi.org/10.5194/egusphere-egu25-6079, 2025.

Starch remains a popular raw material for biobased plastics. However, the rising demand for biobased plastics raises concerns about its supply and environmental sustainability due to the land required for starch production. In Indonesia, cassava starch is the primary raw material used in biobased plastic production. Sago, an underutilized paludiculture crop, is proposed as a sustainable alternative to cassava starch. In this study, we evaluated the socio-economic benefits of cassava and sago cultivation by examining their financial (farm-level and value-added) and societal impacts. Furthermore, we compared the competitiveness of sago and cassava to maize on mineral soils and oil palms on peatlands.
Our study results show that sago is financially less profitable than cassava per hectare for farmers. The net present value of sago cultivation on peatland is less than one-third of cassava farming on mineral soil. This lower profitability is primarily due to sago's low productivity and the long period required before the first harvest. However, when integrating societal benefits and environmental impacts, starch sourcing from sago is more socially beneficial than cassava, as it generates significantly lower CO₂ emissions. Additionally, long-term sago cultivation can be substantially more profitable than cassava, considering no replanting is needed and optimal yield is achieved. Furthermore, sago offers broader advantages related to peatland restoration programs that support local economic activities, as it does not emit CO₂ during cultivation nor require peat drainage.
This study concludes that as a paludiculture crop, sago can provide a viable feedstock for biomaterials while effectively supporting peatland restoration.

How to cite: Sutawijaya, I. B. G., Suwarno, A., and Hein, L.: Socio-economic benefits of starch crops for biobased plastics: comparison between cassava and sago in Indonesia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18610, https://doi.org/10.5194/egusphere-egu25-18610, 2025.

Tropical peatlands are one of the most carbon-dense ecosystems on Earth. However, their long-term resilience to climate and environmental changes, including fire events, remains poorly understood and is understudied compared to boreal and temperate peatlands. This study represents the first palaeoenvironmental research conducted on the peatlands of Guyana, addressing a critical knowledge gap in understanding the long-term dynamics of tropical peatland ecosystems in this region. Further knowledge of these dynamics is essential for understanding the vulnerability of these ecosystems in the face of climate change and increasing anthropogenic disturbances.

This study investigates the fire history of peatlands in Guyana by analysing charcoal and radiocarbon data from two peat cores. Fieldwork involved the collection of cores from various sites in Guyana, representing different hydrological and vegetation conditions. Charcoal analysis is being conducted to quantify fire events, identifying both their frequency and intensity over time. Radiocarbon dating has been used to establish basal dates of peat accumulation in the two cores, of 970 and 6450 years. Higher resolution radiocarbon dating is being used to establish a chronological framework for fire episodes, enabling the reconstruction of long-term fire history. Complementary analyses, including organic matter characterisation through thermogravimetric analysis, provide additional context on how fire events may have influenced peat composition and carbon storage. 

Preliminary observations suggest the presence of charcoal-rich layers within the peat cores, indicating continued fire activity over time with varying intensity. These layers vary between the two sites, suggesting localised differences in fire history. These are potentially driven by differing vegetation types, hydrological conditions, or human influence. By the time of conference, we anticipate presenting a timeline of fire episodes, linked to rates of peat accumulation and potential environmental drivers such as shifts in climate or human land use.

This research provides critical insights into the role of fire in tropical peatland development, offering a unique perspective on the interactions between fire, carbon accumulation, and ecosystem dynamics in this under-researched region. The findings have significant implications for the conservation and management of tropical peatlands, emphasising the need to consider historical fire regimes when predicting future ecosystem resilience/vulnerability. Overall, this study contributes to the broader understanding of tropical peatlands as dynamic carbon reservoirs that are increasingly threatened by global environmental change.

How to cite: Swan, A., Puerta Quintana, Y. T., Kuneš, P., Holder-Collins, K., Hamer, S., Mateo Beneito, A., Lawson, I., Roucoux, K., and Hastie, A.: Fire History in Guyanese Peatlands: Insights from Charcoal and Radiocarbon Data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18106, https://doi.org/10.5194/egusphere-egu25-18106, 2025.

The high central Andes have experienced significant hydroclimatic changes in recent decades, impacting ecosystems through glacier retreat, temperature variations, and altered precipitation seasonality. Andean peatlands are crucial to water and biogeochemical cycles and are sensitive to climate change. To infer past climatic and environmental conditions, we analyzed X-ray fluorescence (XRF) core scanning data, principal component analysis (PCA) with clr-transformation, and total organic carbon (TOC) on the APA01 peat core (basal age ~2500 years). PCA-clr explained 88.8% of variance, revealing interactions between organic matter (OM) content, accumulation dynamics, and climatic influences. The correlation between Log [S/Ti] and PC1-clr highlighted the interplay of OM concentration and erosion intensity. Environmental proxies such as Ln [Si/S] and Ln [Zr/Ti] ratios provided insights into accumulation processes and climatic impacts. Analysis of carbon accumulation rates (CAR) and mineral accumulation rates (MAR) from 507 BCE to 1565 CE indicated distinct phases of organic and mineral accumulation, reflecting climatic changes.

Comparative analysis with regional climate records (Quelccaya and Illimani ice cores, Pumacocha Lake sediments) during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) demonstrated broader climatic influences on peatland dynamics. Decreased OM accumulation during the MCA was linked to drier conditions, while increased accumulation during the LIA corresponded to wetter climates. Warming phases such as the MCA, post-LIA, and recent decades showed high clastic mineral input without necessarily wetter conditions, likely due to glacier and permafrost melting and increased snow-to-rain proportion. Our data indicate a decline in peatland growth and OM accumulation since 2010, emphasizing the need for careful monitoring and future restoration efforts.

How to cite: Huaman Navarro, Y. E., Turcq, B., and Turcq, P.: Late Holocene paleoclimate in the central Andes of Peru based on peatland record, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1088, https://doi.org/10.5194/egusphere-egu25-1088, 2025.

Tropical peatlands are among the most carbon-dense terrestrial ecosystems, but we lack an understanding of their sensitivity to environmental change. Dynamic peat models provide a way to understand the tipping points in peatland formation, and can be constrained using a palaeoecological approach, namely the peatlands' successional stages of development identified through peat core (pollen) analysis. 

Using the 1D-HPMtrop dynamic peat model we simulate the peat accumulation process in two ecosystems of the Peruvian Amazon: a Pole Forest (PF) (7809-cal yr BP) and Palm Swamp (PS) (1215-cal yr BP), parameterized using net primary productivity (NPP) and decomposition rate (k_exp) data from field plots. We incorporate a novel concept of palaeoecological period within the existing model code (derived from pollen diagrams at the two sites). Period-specific parameters were derived based on the assumption that current ecosystem parameters could represent similar conditions in the past and the calibration of sensitive variables to reflect these conditions accurately.  

This implementation enhances the HPMtrop structure, making it a more flexible model capable of generating age-depth curves based on period-specific parametrization. The curves can be compared with the reference age-depth curve derived from radiocarbon dating. Therefore, it is important to understand the nature of the ecosystem in each period or stage, including the parameters associated with each ecosystem type and the driving conditions. A reliable simulation of the peat-depth curve enables sensitivity analysis, allowing us to develop hypotheses about changes in peat accumulation under changes in key parameters.  

We vary key drivers and parameters including anoxia rate, NPP, k_exp, and precipitation to understand the vulnerability of these two tropical peatlands to environmental change. We find highly variable sensitivity to different parameters with NPP being the most influential variable. The impact also varies in magnitude between PS and PF ecosystems. These ecosystems face a variety of threats, and our results could potentially be used to inform conservation and management strategies in some of the most carbon-dense ecosystems on Earth.

How to cite: Puerta Quintana, Y. T., Lawson, I., Frolking, S., Dargie, G., Honorio, E., and Hastie, A.: Simulation of peat accumulation dynamics: Insights from a Pole Forest and Palm Swamp in Amazonia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19667, https://doi.org/10.5194/egusphere-egu25-19667, 2025.

Wetlands and peatlands in Peruvian Amazonia are important for their unique biodiversity, carbon storage, and flood regulation. They also underpin the livelihoods, cultural traditions, and spiritual beliefs of indigenous communities, including the Urarina in the Loreto region, who hold extensive traditional knowledge of these ecosystems. However, this knowledge and the ecosystems themselves face threats from extractive industries and infrastructure development, which disrupt indigenous territories and degrade the environment.

This study integrates Urarina traditional knowledge with scientific methods to explore wetland and peatland ecosystems. Fieldwork was conducted in four Urarina communities along the Chambira River basin, combining social and ecological data collection. We conducted 62 semi-structured interviews to refine the known socio-cultural values of these ecosystems, established 36 forest plots to characterize forest structure and floristic composition, and collected substrate data to assess water table depth, peat thickness, and chemical properties. Remote sensing techniques, including supervised classification of Sentinel-2 and Landsat-8 imagery, were used to map the distribution of Urarina ecosystem types.

The Urarina recognize eight distinct wetland ecosystems, each characterized by unique ecological features, traditional uses, and cultural significance. The study confirms the peat-forming nature of several ecosystems, such as alaka, jiiri and enüüa lauinaa, noting the nutrient-poor, rain-fed substrates of jiiri and enüüa lauinaa. Spatial analysis reveals that jiiri and leuuaku are the most extensive, emphasizing their ecological and cultural importance.

By integrating traditional knowledge with scientific research, this study advances our understanding of these ecosystems and supports conservation and sustainable management policies in Peruvian Amazonia.

How to cite: Honorio Coronado, E. and Roucoux, K. and the collaborators of RAINFOR and the Tropical Wetlands Consortium: Ecological characteristics and spatial distribution of Urarina peatland and wetland ecosystems in Peruvian Amazonia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10082, https://doi.org/10.5194/egusphere-egu25-10082, 2025.

Methane is an important greenhouse gas with a strong infrared radiation absorbing effect approximately 25 times higher than that of CO₂. The global atmospheric methane concentration (GAMC) has increased from ~715 ppb to ~1853 ppb since the Industrial Revolution, which may have led to an ~18% increase in the global total solar radiation absorption. Therefore, understanding the causes of variations in GAMC is a crucial issue in global climatic change research. The long-term trend of atmospheric methane concentration recorded in ice cores roughly followed the orbital cycles in the northern hemisphere solar insolation. However, since the mid-Holocene, these two have become ‘decoupled’. Currently, there is still considerable controversy regarding the explanation for this ‘decoupling’. Previous studies believed that the temperature increase during the Holocene led to the expansion of wetland areas in high latitudes of the Northern Hemisphere, emitting substantial amounts of methane, which played a dominant role in the increase in global methane concentration. However, as research progresses, the impact of hydrological cycles in low-latitude regions has gradually gained attention, with the dry conditions in the mid-Holocene likely resulting in reduced methane emissions from wetlands in low-latitude regions. In addition to the influence of these natural factors, numerous studies have also focused on methane emissions from early agricultural practices (rice cultivation), with the expansion of rice paddies in the late Holocene emitting large amounts of methane.

To discuss the impact of natural and anthropogenic factors on the trends in atmospheric methane concentration, we collect methane emission flux data from global wetlands and rice paddies (a total of 377 sites) for analysis and comparison. We believe that during the mid-Holocene, with primitive agricultural production techniques and a smaller population, methane emissions from rice paddies were insufficient to reverse the trend in global methane concentration, which was likely more influenced by natural factors. Additionally, we find that the Holocene GAMC trend closely follows the long-term trend in global low latitude wetland extent, as inferred from our lake-level reconstruction and from other existing hydroclimate records, implying that changes in tropical-subtropical wetland areas could play a major role in the natural global methane cycle. The reduction in the area of low latitude wetlands during the mid-Holocene, caused by increased submersion from sea level rise and by reduced subtropical water availability inferred from decreased lake levels, could have led to the observed mid-Holocene GAMC fall. 

How to cite: Song, Y., Xu, H., and Yeager, K. M.: Possible influence of low latitude wetland area changes on the Holocene global atmospheric methane concentration trend, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7838, https://doi.org/10.5194/egusphere-egu25-7838, 2025.

The carbon and nitrogen budgets, as well as greenhouse gas (GHG) fluxes, in peatlands of the Congo Basin – most likely the largest tropical peatland area – remain almost unexplored. In March 2024 (dry season) and November 2024 (wet season), we conducted measurements of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) fluxes, along with peat chemistry, in a hardwood peat swamp forest and peaty savanna in Epena, Republic of the Congo. Manual soil and tree stem chambers were used to collect gas for further analysis using a Shimadzu gas chromatographer. Soil temperature, pH, O₂, water content, and groundwater table (GWT) levels were measured using portable analysers. Additionally, soil, trunk wood and tree leaves were sampled for subsequent physico-chemical and microbiome analysis. All the laboratory analyses were carried out at the University of Tartu. Four sampling sessions were conducted during both the dry and wet season, providing data across typical seasonal variation for the Congolese peat swamp ecosystem.
In the dry season (GWT −0.5 to −2.0 m), respiration of CO₂ from peat was relatively high (160–280 mg C m^–2 h^–1 as site averages) while the peat consumed 0.045…0.055 mg CH4-C m^–2 h^–1 as site averages. N₂O fluxes were very low while only the forest peat showed a significant N₂O emission of 96 μg N m^–2 h^–1. We explain the pattern with severe heat (up to 42^oC in topsoil) and dryness (down to 0.36 m³ water m^–3 topsoil). CH₄ was consumed in the peat while low CH₄ emissions were observed from Raphia sp. palm stems. Soil abundances of control genes associated with the N₂O and CH₄ cycles were low, likely due to the heat and dryness. In the dry season, preliminary gene analysis showed presence of archaeal nitrifiers and denitrifiers in the forest peat, with absence of bacterial nitrifiers. Fungal denitrifiers were also present in the peat of both ecosystems.
In the wet season (GWT –0.3 to +1.5 m), respiration of CO₂ from peat was expectedly low (54–81 mg C m^–2 h^–1 as site averages). Both the forest and savanna emitted CH₄ (0.12…1.0 and 0.033…0.18 mg C m^–2 h^–1, respectively, as site averages) and no significant amount of N₂O, as expected from a waterlogged ecosystem. The modest CH₄ emissions were explained by variability of O₂ with the uneven ground surface, the mobile groundwater and the flow connection to Likouala riverwater.

How to cite: Mander, Ü., Pärn, J., Espenberg, M., Soosaar, K., Ndolo Ebika, S., Bouka Dipelet, G., Kuusemets, L., Mander, S., Khanongnuch, R., Kanger, K., Brugière, D., and Loumeto, J.: Greenhouse gas fluxes and microbiome in a peatland forest and peaty savanna in Epena, Republic of the Congo, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7308, https://doi.org/10.5194/egusphere-egu25-7308, 2025.

Peatlands are globally significant carbon reservoirs, with the potential to either mitigate or exacerbate climate change. However, compared to high-latitude peatlands, low-latitude peatlands have received relatively little attention and remain poorly understood. In this study, we investigated peatlands from various regions of China, classifying peat types and analyzing bulk density, carbon and nitrogen content, organic carbon fractions, microbial community composition, and other parameters across different peat depths. Several proxies exhibited clear patterns along the depth gradient. Using the AMS ¹⁴C dating method, we observed substantial spatial variations in the long-term carbon accumulation rates of these peatlands. In future analyses, the measured peat properties will be integrated with carbon accumulation data to further elucidate these dynamics.

How to cite: Zhang, H.: Peat properties and long-term carbon accumulation rates in regional peatlands of China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14103, https://doi.org/10.5194/egusphere-egu25-14103, 2025.

Peatlands represent a significant global carbon (C) stock, constituting 25% of soil carbon despite occupying 3% of the continental surface. Sometimes buried below the soil surface, peat is mainly composed of fossil plant debris and thus has considerable potential for paleoenvironmental reconstruction (e.g. pollens, macrofossils) and storing organic C. In the context of global change, peatlands face a range of anthropogenic and climate forcing that can disrupt their functioning and capacity to store C at the surface and at depth. Examples of such changes include drainage and peat extraction, which can encourage the decomposition of organic matter and the release of C into the atmosphere. Mapping the extent of (past-) peatland is essential for peat volume estimation and to protect and restore peatland functions. However, mapping large areas of fossil alluvial peatlands, using current remote sensing methods is not always straightforward. As is often observed in northwestern Europe, peatlands are frequently covered (fossilised) by loamy colluvium and alluvium resulting from soil erosion, especially in the upstream sections of small valleys.

This is the case of the Somme basin (northern France), which contains an extensive alluvial peatland, mostly fossil, where a large amount of peat accumulated during the Holocene (up to 11 m). The research, initiated in 2020, provides a precise reconstruction of the variations in the dynamics of peat accumulation in the Somme river basin over 15 ka (Garcia et al., 2024)ⁱ. The challenge for the current research is to quantify the volume of peat and C stocks based on morphostratigraphic and geochemical data.

Firstly, stratigraphic and geochemical data from three valley transects (Long, Morcourt, Tirancourt) were used to estimate current and past (pre-extraction) C stocks from peat, peaty silt, organic silt per site, locally representing a 38% loss such as in Long. Secondly, 750 punctual peat cores were digitalised through the basin (peat thickness GIS database) to define the potential fossil peat envelope (33,315 ha). Peat volume was modelled at the scale of the main valleys in the catchment using an interpolation method. The average C content per cubic meter of peat stratigraphic units (45.4%) was applied to the total volume per site and for the basin to estimate the C stocks. The preliminary results give a potential of 1,2 cubic kilometres of peat for 64 million tonnes of C. Thirdly, the volumes extracted in the modern period are calculated based on the current surface area of the valley ponds (former extraction pits, about 1/3 of the wetland area). The results will be available to environmental managers and institutions to raise awareness of carbon storage issues in fossil peat.

How to cite: Garcia, C., Kramarczyk, E., Antoine, P., Grimaud, J.-L., and Brasseur, B.: Mapping a large fossil alluvial peatland and modelling peat and C volume: first results from the Somme basin (northern France), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10625, https://doi.org/10.5194/egusphere-egu25-10625, 2025.

Peat soils are estimated to store over 500 Gt of carbon (Yu, 2012), and their ongoing sequestration plays a pivotal role in mitigating climate change. However, improved measurements of peat carbon content are necessary due to inherent differences between peat soil environments. Emphasis has been placed on accurately measuring carbon content in peat samples to understand carbon dynamics and estimate their stores. A protocol developed by Chambers et al., (2011) requires the mechanical grinding of peat samples before elemental analysis. Yet, there has been a lack of investigations into how different grinding methods may directly affect carbon measurements in peat soils.

Previous studies (Abulikemu, 2023; Markert, 1995; Pulleman et al., 2021; Siang, 2010) have investigated the influence of grinding on organic materials. Results indicate differences in the extent of carbon alteration and release depending on the grinding method employed. The shock and abrasive forces of ball mill grinding generate mechanochemical alterations in organic matter (Abulikemu, 2023), whilst pestle and mortar grinding relies on friction and pressure (Markert, 1995). Energy generated during ball mill grinding has been linked to higher oxidation and pyrolytic reactions (Abulikemu, 2023; Siang, 2010).

Given these findings, the choice of grinding method may artificially alter the carbon in peat soils, providing misleading measurements of carbon content and accumulation rates. This research examines the influence of two commonly utilised grinding methods, ball mill and pestle and mortar. Four peat samples were ground using both methods and measured using an elemental analyser. Seven subsamples from each ground sample were measured separately (Total = 56). The uppermost sample, from acrotelmic peat, showed no significant differences (p > 0.05), whereas the three lower, more decomposed, catotelmic peat, suggest high significance (p < 0.001). In all cases, pestle and mortar ground samples displayed higher carbon values than their ball mill counterparts.

These findings align with previous studies, suggesting that the choice of grinding method may influence the carbon content of organic material (Abulikemu, 2023; Pulleman et al., 2021; Siang, 2010). Thus, concerns are raised here regarding the influence of grinding and the comparability of results.

Abulikemu, G., 2023. Role of grinding method on granular activated carbon characteristics.

Chambers, F.M., Beilman, D.W., Yu, Z., 2011. Methods for determining peat humification and for quantifying peat bulk density, organic matter and carbon content for palaeostudies of climate and peatland carbon dynamics. Mires Peat 7, 1–10.

Markert, B., 1995. Sample preparation (cleaning, drying, homogenization) for trace element analysis in plant matrices. Sci. Total Environ., State of the Art of Trace Element Determinations in Plant Matrices 176, 45–61. https://doi.org/10.1016/0048-9697(95)04829-4

Pulleman, M., Wills, S., Creamer, R., Dick, R., Ferguson, R., Hooper, D., Williams, C., Margenot, A.J., 2021. Soil mass and grind size used for sample homogenization strongly affect permanganate-oxidizable carbon (POXC) values, with implications for its use as a national soil health indicator. Geoderma 383, 114742. https://doi.org/10.1016/j.geoderma.2020.114742

Siang, K.S.Q., 2010. The rates of formation of carbon and gases from high energy ball milling of organic compounds.

Yu, Z.C., 2012. Northern peatland carbon stocks and dynamics: a review. Biogeosciences 9, 4071–4085.

How to cite: Ryan, C., Li, N., De Castro Amaral Siqueira, C., Hoch, H., Stock, M., Curran, M., Shaw, H., and Orme, L.: Carbon measurement of peat soils: Significant differences between two grinding methods, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4838, https://doi.org/10.5194/egusphere-egu25-4838, 2025.

The IPCC Wetlands Supplement (2014) incorporates the only internationally agreed global guidelines to report on greenhouse gas emissions from and removals by peatlands. It has been 10 years since its publication and the Wetlands Supplement no longer reflects the latest data or approaches adopted by countries for calculating emissions, presenting a constraint on their efforts to measure and report emissions from the land use sector. The Peat Emit project (part of the Aim4Forests programme managed by FAO) has collected, assessed and updated greenhouse gas emission factors for peatlands in low- and middle-income countries. Specifically, compared to the Wetlands Supplement, it has (i) developed more accurate emission factor estimates for a wider range of land-management options and land use/cover categories than reported in the Wetlands Supplement; (ii) refined approaches to greenhouse gas emissions reporting; and (iii) produced robust criteria for evaluation of data quality.  This poster outlines our approach with examples of updated emission factors for a range of land use/cover categories.

How to cite: Page, S., Freeman, B., Jovani Sancho, J., Evans, C., Warren, M., and Nuutinen, M.: The Peat Emit Project: Providing Enhanced Support to Countries in Efforts to Assess and Report Peatland GHG Emissions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2153, https://doi.org/10.5194/egusphere-egu25-2153, 2025.

The frequency of extreme events worldwide is steadily increasing. Therefore, it is crucial to recognise the accompanying response of different ecosystems. Monoculture forests with simplified ecosystem linkages are particularly vulnerable to catastrophic events. Fires or infestations threaten forests and other associated ecosystems, including peatlands, which are extremely important in regulating the global carbon cycle and thus mitigating the effects of a warming climate. Peatlands, due to their acidic and anaerobic conditions, are a good source of valuable information about past ecological disasters. Here, we examine how a peatland located in one of Poland's largest forest monoculture complexes responded to some of the largest environmental disasters in Central Europe in the 20^th century – the 1922–1924 insect infestation and the 1992 fire. We analyse a peat core from Miały peatland surrounded by a Scots pine (Pinus sylvestris) plantation – the Noteć Forest (NE Poland). Our reconstruction is based on high-resolution multiproxy palaeoecological analyses, including pollen, plant macrofossils, charcoal and testate amoebae supported by neodymium isotopes as a disturbance proxy.

We show several critical transitions in the peatland associated with the extreme events manifested by a change in the hydrological and trophic conditions in the peatland. We highlight the interpretative value of fungi, often disregarded in paleo-records, as bioindicators of rapid environmental changes. We also emphasize the importance of the historical background to understanding subsequent environmental changes. The study results are essential for forest ecology and forest management in the temperate climate of Central and Eastern Europe. Furthermore, we want to underline the significance and importance of wetlands ecosystem services for forest ecosystems and sustainable forestry.

The study is financed by the National Science Centre, Poland, grant no. 2020/39/D/ST10/00641.

How to cite: Bąk, M., Lamentowicz, M., Kołaczek, P., Wochal, D., Jakubowicz, M., and Marcisz, K.: 20th-century ecological disasters led to peatland critical transitions in central European pine monoculture forest, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-985, https://doi.org/10.5194/egusphere-egu25-985, 2025.

Palaeoecological studies reporting long-term development history of subarctic fens are scarce and overall permafrost-free peatlands located at the immediate vicinity of permafrost zone have deserved little attention in Fennoscandia. We use a multiproxy approach to study millennial-scale dynamics of two peatlands located in Finnish Lapland (Katsapuli and Maader). In addition to study autogenic succession and external forcing, we aimed in resolving the impact of surrounding landscape changes, potentially related to reindeer herding. The pollen data does not indicate major regional-scale vegetation changes but suggest an increase in the proportion of sedges towards modern times and decrease in tree pollen. These, together with an increase in regional fire events based on micro-charcoal and erosion rates measured as sediment mineral component coincide with both colder temperatures (Little Ice Age) and the emergence of reindeer-based pastoralism. The peat macrofossil data of the two profiles suggest a clear and relatively simultaneous local regime shift from sedge-dominated local habitat conditions to a Sphagnum community, where S. lindbergii becomes increasingly dominant towards the present day, suggesting prevalence of relatively moist conditions. In both sites, the regime shift is coeval with the onset of Medieval Climate Anomaly (MCA) climate conditions. Newly- established communities are sustained thereafter. Vegetation changes to Sphagnum mosses resulted in high peat growth rates, thus most of the peat stock is relatively new. Based on these data, we suggest that Sphagnum moss communities are resilient to climate fluctuations and might continue to act as effective carbon accumulation systems under warmer climates.

How to cite: Väliranta, M., Piilo, S., Kuoppamaa, M., Tahvanainen, T., Kumpula, T., Kuosmanen, N., and Macias-Fauria, M.: Drastic Peatland Regime Shift and Landscape Disturbances Connected to Warm and Cold Climate Events Over the Past Centuries in Subarctic Finland  , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3584, https://doi.org/10.5194/egusphere-egu25-3584, 2025.

Peatlands are important carbon stocks, yet they are also highly susceptible to ongoing climate change and other direct anthropogenic impacts. Many peatlands across Europe have been either destroyed or partly damaged, and anthropogenic disturbance intensified over the last 300 years. Conservation of these ecosystems is, therefore, necessary to protect various ecosystem services provided by peatlands, e.g., water retention, carbon sequestration, and biodiversity protection. This contribution aims to present two palaeoecological case studies that supported the creation of two new nature reserves in the Tuchola Forest in Northern Poland in 2024 – “Torfowisko Jezierzba” (Jezierzba Peatland) and “Torfowisko Okoniny” (Okoniny Peatland). Both peatlands are located within a large Pinus sylvestris monoculture forest complex managed by the State Forests. In both cases, palaeoecological investigations involved high-resolution analyses of various palaeoecological proxies and the studies of historical materials and maps, while at the Jezierzba peatland, remote sensing analyses were additionally carried out to assess the current ecosystem state (Bąk et al. 2024; Tipton et al. in review). Moreover, dendrochronological data helped to assess the state of forest stands and the response of pine trees to climate change. Invaluable was a close cooperation with local foresters from Woziwoda and Tuchola Forestry Districts who supported our investigations.

Research funded by National Science Centre, Poland (2020/39/D/ST10/00641) and EEA Grants/Norway Grants (MFEOG.07.02.01-50-0028/21-00).

Bąk, M., Lamentowicz, M., Kołaczek, P., Wochal, D., Matulewski, P., Kopeć, D., Wietecha, M., Jaster, D. & Marcisz, K. (2024) Assessing the impact of forest management and climate on a peatland under Scots pine monoculture using a multidisciplinary approach. Biogeosciences, 21, 5143-5172.

Tipton, J., Marcisz, K., Łuców, D., Obremska, M. & Lamentowicz, M. (in review) Utilizing testate amoebae as key indicators of critical transitions in historical forest management: a case study of Scots pine monoculture.

How to cite: Marcisz, K., Bąk, M., Tipton, J., Kołaczek, P., Wochal, D., Matulewski, P., Jaster, D., Kopeć, D., Wietecha, M., Łuców, D., Obremska, M., and Lamentowicz, M.: How can peatland palaeoecology support nature conservation? Two examples from the Tuchola Forest, Poland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8575, https://doi.org/10.5194/egusphere-egu25-8575, 2025.

Peatlands are critically important ecosystems, yet they are facing significant risks due to anthropogenic pressures. In Europe, drying of pristine peat ecosystems during the recent decades have been observed due to both direct and indirect anthropogenic impacts. Historically, peatlands have also been extensively drained by human activity, but efforts to restore them to their natural state have recently increased. The combined effects of climate change and human activities are expected to influence the carbon dynamics of peatlands in the future. Changes in peatland microbial communities can be used to assess past changes of peatlands as well as the current soil health.

Microscopical testate amoebae play a crucial role in peatland carbon cycling as important members of microbial communities, acting as predators and decomposers. Testate amoebae are sensitive to changes in moisture conditions and, therefore, they have traditionally been used to model past moisture conditions in peatlands. However, the response of peatland microbial communities to restoration needs further investigation, as it is essential for improving our understanding of the underlying processes affecting carbon cycling in these ecosystems.

This study aims to examine changes in testate amoeba communities in forestry-drained peatlands in the boreal zone over time including time before, during, and after peatland drainage and restoration. The study seeks to expand the understanding of the community structure of testate amoebae in peatlands, particularly in forested peatlands/swamps, as there is a lack of research on testate amoeba community structure in these habitats.

In this study, testate amoeba analyses have been conducted on three peatlands located in southern Finland: one serves as a natural reference site, while the other two have been drained and subsequently restored. Preliminary results suggest that the structure of testate amoeba communities varies significantly across different peat layers in the reference site. In the drained and restored sites, testate amoeba communities in some peat cores indicate the presence of species typical of moister habitats at shallower peat depths (restored sections), whereas the signal in other cores remains more unclear.

How to cite: Pilkama, E., Piilo, S., Minkkinen, K., Hautala, R., Pikkarainen, M., and Väliranta, M.: Testate Amoeba Community dynamics in Forestry-Drained and Restored Peatlands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3600, https://doi.org/10.5194/egusphere-egu25-3600, 2025.

The research aims to discover over what timescales current environmental conditions were emplaced, and is there evidence for a significant change in biodiversity? Do the peatlands (bog and fen) represent healthy ecosystems or indicate a trend towards biogeochemical degradation? Are the predicted future changes in precipitation and temperature because of global warming likely to initiate significant changes in peatland hydrology, biogeochemistry, and biodiversity, and what mitigation options might be explored to manage the problem?

The research will utilise various biotic and abiotic proxies to answer these questions. Testate amoebae will provide information on water table depth and can be used in reconstructing past hydrological conditions. Vegetation changes will be investigated using pollen and plant macrofossils. These can assist in distinguishing wet and dry phases in peatland history. The degree of humification will be assessed through analysing the biogeochemistry of the peat horizons extracted. Carbon/Nitrogen Ratios reflect decomposition and organic matter quality and stable Isotopes (e.g., δ¹³C, δ¹⁵N) indicate changes in vegetation type, hydrology, and decomposition processes. X-ray Fluorescence will be used to determine elemental composition (e.g., Ca, Fe, Ti) to infer environmental changes such as nutrient influx or atmospheric deposition. Analysis of carbonaceous particulate matter will allow us to investigate pollution events through time as well as fire history. Detailed dating of deposits over approximately the past 1000 years will be achieved using radiocarbon and Pb²¹⁰ dating. The evidence of changing hydrological and biogeochemical conditions gained through using these various proxies will be compared to present day surface data (vegetation, pH, Eh, Dissolved Organics).

To consider the likely effects of future climate change scenarios, we will evaluate the above findings within the context of Natural England’s Long-Term Monitoring Network (LTMN) datasets to increase understanding around the likely effects of climate change based on the latest climate models and explore potential beneficial mitigation options for each key site.

Recent field work has yielded the first set of cores from the Fenn’s, Whixall and Bettisfield lowland raised bog on the border of the English county of Shropshire and north Wales. We will present the findings from the preliminary palaeoenvironmental analyses of these cores. Further core samples will be taken from this site and other LTMN sites during 2025. Applications are being made to access protected Natural England peatland sites at Malham Tarn Moss and Featherbed Moss in northern England.

The findings from the research will inform Natural England on the historical development of LTMN sites including lowland raised bogs and fens as well as upland blanket bogs. Ongoing data collection on several nature reserves across England has been carried out since 2009, including vegetation, soil chemistry, air quality, mesofauna and microbes. A major challenge identified by the project, however, is a poor understanding of the historical context and likely future development of the environment at each reserve, particularly the response of peatland habitats to future climatic change.

How to cite: Hindson, R., Branch, N., Robinson, S., and Silva, B.: Evaluating changes in Holocene and Anthropocene biodiversity and healthiness of Peatlands in England (UK), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5014, https://doi.org/10.5194/egusphere-egu25-5014, 2025.

Taiga is one of the world’s largest boreal forest areas that, together with peatlands, span extensive regions of Siberia. Over the past, it has been subject to changes influenced by natural factors and human activity, which utilized available timber and raw materials for their needs. However, Western Siberia's coupled taiga and peatlands history remains insufficiently studied. We lack a comprehensive understanding of the extent to which indigenous people, including the Khanty, influenced taiga through logging, grazing, or controlled fires before the intensive forest exploitation that commenced in the 20th century. Therefore, our research focuses on the palaeoecological reconstruction of environmental changes over the past 1600 years in the Khanty-Mansiysk region (Western Siberia). We employed pollen, testate amoebae, and charcoal from Shapsha bog to reconstruct past dynamics of taiga vegetation and associated changes in the peatland. Our results demonstrate that indigenous communities probably had minimal impact on the natural environment. We also recorded a forest fire at the turn of the 14th and 15th centuries. It may have transformed the ecosystem by raising water levels, enhancing peat accumulation, and fostering peatland growth. Our records indicate that human activities began significantly impacting the environment from the 16th century. The Russian colonization of Siberia is likely responsible for these changes, as it involved organized action of taiga deforestation for purposes such as building settlements, creating trade routes, and developing agriculture.  In connection with colonization, Russian settlers took over local areas near the peat bog from the indigenous population and created the town of Shapsha.

This research was funded in the framework of the National Science Centre grant No. 2021/41/B/ST10/00060 and INTERACT No. 730938 - PeatHOT project, and within the frame of the IDUB (Excellence Initiative—Research University) programme (003/13/UAM/0007 and 003/13/UAM/0008).

How to cite: Lamentowicz, M., Słowiński, M., Marcisz, K., Czerwiński, S., and Łuców, D.: Palaeoecological peatland study highlights human impact on the environment of Western Siberia's taiga, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11721, https://doi.org/10.5194/egusphere-egu25-11721, 2025.