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Peatlands, shaped by centuries of human activities, now face a primary threat from mining activities. Vulnerable to drainage and hydrological instability, peatland areas encounter challenges that compromise their ecological integrity. This study hypothesised that permanent water reservoirs within mines could serve as refugia for water beetles from adjacent areas prone to drying in the summer. Employing standard methods, including entomological scraping and water traps, samples were collected. Results revealed that, in most cases, water beetles exhibited a preference for the Nature 2000 area untouched by mining. Despite unfavourable conditions, the Nature 2000 area showcased a more diverse water beetle fauna. Remarkably, the selected Nature 2000 area, despite its identified degradation based on flora, remained a biodiversity hotspot for peatland water beetle fauna. The study underscores the significance of assessing insects, particularly beetles, as rapid responders to environmental changes. This evaluation holds crucial implications for peatland restoration planning and decision-making regarding mining investments in proximity to peatland areas. [ABSTRACT FROM AUTHOR]

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All over the world, peatlands have been drained, often for agricultural purposes, resulting in CO2 emissions, soil subsidence and biodiversity loss. To combat these negative effects, drained peatlands are being rewetted, but knowledge of the effects of rewetting on peat biogeochemistry is still incomplete, especially since a variety of rewetting methods and rewetting degrees exists. We conducted a mesocosm experiment in which we exposed 100 intact agricultural fen peat cores (80 cm, 20 cm Ø) to five different water levels (0, 20, 40, 60 cm and variable—surface), two nutrient application levels to mimic continued agricultural use, and two water origins. Over an eight-month period, we harvested above-ground plant biomass five times and sampled pore water at two depths each month. Samples were analysed for nutrients. Our results show increased phosphate and ammonium availability upon fully rewetting (0 cm—surface) and less so under partially rewetted circumstances (20 cm—surface). Above-ground biomass was strongly affected by nutrient application, especially in the high water level treatments. Vegetation was primarily N-limited, and N in the vegetation decreased with increasing water levels, indicating stronger nitrogen limitation upon rewetting. We conclude that nature restoration under fully rewetted conditions will likely be challenging as a result of the large release of nutrients from the system which may also affect surrounding nature areas. Furthermore, we conclude that partial rewetting combined with low-intensity agricultural use can be a solution to slow down the adverse effects of drainage, although this will lead to decreased agricultural production. [ABSTRACT FROM AUTHOR]

Degraded peatlands release large amounts of greenhouse gases. The development of effective mitigation and management measures requires an understanding of relevant site‐specific biogeochemical and hydraulic processes. However, the simulation of water fluxes and vadose zone state variables of degrading peatlands relies on proper process description, parameterization of hydraulic functions, and representation of the boundary conditions. The objective of this study was to analyze the effects of unimodal versus bimodal soil hydraulic functions and pressure head versus flux‐type lower boundary conditions (LBCs) on the calculated hydraulic characteristics of a degraded peat profile. HYDRUS‐1D was used to study the hydraulic flow dynamics parameterized with data from a weighable groundwater lysimeter for the period from May 1 to December 31, 2019. Simulations comparing uni‐ and bimodal hydraulic functions showed only minor differences. Simulations of soil water pressure at a depth of 30 cm using a flux‐type LBC (RMSE: 27 cm, where RMSE is root mean square error) performed better than simulations using a pressure head LBC (RMSE: 48 cm). The pressure head LBC performed better at simulating volumetric water contents in 30‐cm depth than the flux LBC variant (RMSE: 0.05 vs. 0.09 cm3 cm−3). For specific site conditions with a shallow, fluctuating groundwater table and temporary air entrapment, the choice of LBC was important for a more accurate simulation of soil water fluxes and volumetric water content. Core Ideas: Understanding degraded peatland hydraulics based on groundwater lysimeter data.Simulation of the peat soil water balance as affected by water table dynamics.Comparing unimodal with bimodal soil hydraulic models in water balance simulation.Analyzing the choice of the lower boundary conditions by scenario simulations.Discussion on missing processes not accounted for to improve simulation results. [ABSTRACT FROM AUTHOR]

Management of drained peatlands may pose a risk or a solution on the way towards climate change mitigation, which creates a need to evaluate the current state of forestry-drained peatlands, the magnitude of degradation processes and indicators for carbon (C) loss. Using a large dataset (778 profiles, 891 peat samples, collected between 1977 and 2017) from peatlands having different fertility classes across Finland, we investigate whether the surface peat profiles of undrained and forestry-drained peatlands differ in C:N, von Post and dry bulk density. The utility of element ratios (C:N:H stoichiometry) as site indicators for degradation were further analyzed from a subsample of 16 undrained and 30 drained peat profiles. This subsample of drained sites had carbon dioxide (CO2) and methane (CH4) fluxes measured allowing us to link peat element ratios to annual C gas effluxes. Element ratios H:C, O:C and C:N and degree of unsaturation (combining C, N, H changes) were found widely valid: they captured both differences in the botanical origin of peat as well as its potential decomposition pathway (C lost via a combination of dissolved organic C and C gas loss and/or the gaseous loss predominantly as CO2). Of the stoichiometric indexes, peat H:C ratio seemed to be the best proxy for degradation following drainage, it indicated not only long-term degradation but also explained 48% of the variation in annual CO2 emission. The O:C ratio positively correlated with annual CH4 flux, presumably because high O:C in peat reflected the availability of easily degradable substrate for methanogenesis. The differences in C:N ratio indicated notable decomposition processes for Sphagnum-dominated peatlands but not in Carex-dominated peatlands. Degree of unsaturation showed potential for an integrative proxy for drainage-induced lowering water table and post-drainage changes in peat substrate quality. [ABSTRACT FROM AUTHOR]

Peatlands play a crucial role in the global carbon (C) cycle, making their restoration a key strategy for mitigating greenhouse gas (GHG) emissions and retaining C. This study analyses the most common restoration pathways employed in boreal and temperate peatlands, potentially applicable in tropical peat swamp forests. Our analysis focuses on the GHG emissions and C retention potential of the restoration measures. To assess the C stock change in restored (rewetted) peatlands and afforested peatlands with continuous drainage, we adopt a conceptual approach that considers short-term C capture (GHG exchange between the atmosphere and the peatland ecosystem) and long-term C sequestration in peat. The primary criterion of our conceptual model is the capacity of restoration measures to capture C and reduce GHG emissions. Our findings indicate that carbon dioxide (CO2) is the most influential part of long-term climate impact of restored peatlands, whereas moderate methane (CH4) emissions and low N2O fluxes are relatively unimportant. However, lateral losses of dissolved and particulate C in water can account up to a half of the total C stock change. Among the restored peatland types, Sphagnum paludiculture showed the highest CO2 capture, followed by shallow lakes and reed/grass paludiculture. Shallow lakeshore vegetation in restored peatlands can reduce CO2 emissions and sequester C but still emit CH4, particularly during the first 20 years after restoration. Our conceptual modelling approach reveals that over a 300-year period, under stable climate conditions, drained bog forests can lose up to 50% of initial C content. In managed (regularly harvested) and continuously drained peatland forests, C accumulation in biomass and litter input does not compensate C losses from peat. In contrast, rewetted unmanaged peatland forests are turning into a persistent C sink. The modelling results emphasized the importance of long-term C balance analysis which considers soil C accumulation, moving beyond the short-term C cycling between vegetation and the atmosphere. [ABSTRACT FROM AUTHOR]

Peatland restoration usually aims at restarting the peatlands' function to store carbon within peat. The soil properties of the near-surface peat can give a first understanding of this process. Therefore, we sampled pH value, total organic carbon content (TOC), total nitrogen content (TN), C/N ratio as well as dry bulk density (BD), and describe the structure of near-surface peats in six restored fens in North-East Germany before (2002-2004) and after (2019-2021) restoration. Before restoration, the study sites showed peat degradation to various extents in their near-surface peats. pH values remained relatively stable over time. Comparing the degraded peat horizons, TOC increased significantly in four study sites, ranging from 35.7% to 47.8% in 2002-2004 and from 42.5% to 54.0% in 2019-2021. TN varied from 1.5% to 3.5% in 2002-2004 and from 1.8% to 3.2% in 2019-2021, but changes were only significant in one site, showing a slight decrease. In three sites, the increase in C/N ratio was significant, indicating lower nutrient availability. BD ranged from 0.08 to 0.48 g/cm3 in 2002-2004 and from 0.10 to 0.16 g/cm³ in 2019-2021, decreasing significantly in four sites. The structure of the degraded peat horizons changed after restoration to a more homogenous, sludge mass with larger re-aggregates. In three sites, new peat moss peat layers above the degraded soil horizon were present in 2019-2021, with a mean thickness of 6.8 to 36.1 cm. The structure was comparable to typical, slightly decomposed peat moss peat. Our findings suggest that within about 17 years after fen restoration, and thereby a water table rise close to surface, TOC of the near-surface peats increased to values that are typical for undisturbed peatlands. This indicates that restoration can lead to the re-establishment of peatlands as potential carbon sinks, with TOC within the near-surface peat as one key factor in this process. Further, we assume that the decrease in nutrient availability, decrease of BD, and new, undisturbed peat layers can favor the establishment of mire-specific biodiversity and support ecosystem services similar to near-natural mires. [ABSTRACT FROM AUTHOR]

Rationale: Land‐use changes, e.g., forestry drainage, modify the characteristics of peatland soil and affect the peatland carbon (C) balance. Peat soil nutrient status, related mainly to the original peatland type, also has an impact on the C balance after drainage, as observed earlier at the ecosystem scale for two forestry‐drained sites in Southern Finland. Here the aim was to compare the soil CO2 fluxes from the two sites, nutrient‐poor and nutirent‐rich forestry‐drained peatlands, and study the effect of plant photosynthates on the decomposition of peat C. Therefore, the respiration rates and priming effect (PE) of peat soils with variable nutrient status were examined in the laboratory. Methods: Half of the samples were labelled with 13C‐glucose to study the effect of fresh C addition on the soil decomposition. The 13CO2‐samples were analysed with isotope ratio mass spectrometry. A two‐pool mixing model was applied to separate the soil‐ and sugar‐derived respirations and to determine the PE. Results: The nutrient‐rich peat soil respired generally more than the nutrient‐poor peat. A negative PE was observed in both peat soils, suggesting that the addition of fresh C did not increase the soil decomposition, but on the contrary decreased it. The negative PE was significantly more pronounced in nutrient‐poor peat soil than in the nutrient‐rich peat treatments, suggesting that the higher nutrient availability suppresses the negative PE. Conclusions: These results imply that microbes prefer utilizing fresh C instead of old C in the short term and that the peat decomposition is suppressed in the presence of fresh C inputs from vegetation at forestry‐drained peatlands. These effects are even stronger in peat soils with less nutrients available. Ecosystem scale and soil process models could be improved with the help of these results. [ABSTRACT FROM AUTHOR]

The Drentsche Aa valley system in the glacial sandy landscape of the north-eastern Netherlands, is one of the many regional drainage systems in the north-western to central European Lowlands. Following deep incision in the Weichselian, ca 7 m of eutrophic peat has accumulated in the lower to middle reaches of the valley system in the Holocene, completely filling the Weichselian incision. We reconstructed the rate of water-level rise controlling peat growth at three locations in the valley system (representing the upper, middle and lower reaches), using 14C peat dates from compaction-free sampling sites on the sloping valley margin where the peat directly overlies the sandy Pleistocene subsurface. The 14C dates enabled the construction of curves showing the water-level evolution at each location. Our results show variable rates of Holocene peat growth in the valley system in response to different drivers of hydrological change: a strong increase in annual precipitation (onset Holocene), a decrease in evapotranspiration (10,000–8000 cal. years BP) and relative sea-level rise (after ~4500 cal. years BP). Because the identified hydrological controls on peat growth are regional, they probably ruled Holocene peat growth in many peat-filled valley systems in the north-western to central European Lowlands. Currently, there is growing attention for these valley systems in the context of European nature restoration efforts and climate change adaptation and mitigation measures. The present study underscores that large-scale hydrological measures outside the valley system are needed for restoration of degraded valley peatlands. [ABSTRACT FROM AUTHOR]

Peatlands are significant to global efforts to combat climate change. However, to date, they have been a missing piece in the climate change mitigation policy puzzle in the European Union (EU). Taking a policy coherence perspective, we investigate how policies from different governance levels—that is, EU, member state, and regional levels—support and impede existing and new policies for climate-friendly peatland usage. We put a particular focus on incentive-based policy instruments, because such incentives are often advocated as promising policy instruments for supporting the transition to the sustainable management of peatlands. We selected the three peatland-rich EU countries Finland, Germany, and the Netherlands. Based on semi-structured interviews with 35 experts, we indicate a lack of horizontal policy coherence between agriculture, nature conservation, water management, forestry, energy, and climate policies in terms of climate change mitigation measures on peatlands. At the EU level, most prominently, the Common Agricultural Policy counteracts climate targets because direct payments currently encourage the unsustainable management of peatlands. At the national and subnational levels, water quality in Finland, nature conservation in Germany, and subsidence in the Netherlands were primary objectives of peatland relevant policies. Due to a lack of clear guidance on raising the groundwater table, the current incentive-based policy instruments are ineffective for reducing emissions. Despite its higher mitigation potential, potential incentive-based policies for rewetting encounter various regulatory barriers caused by the policy incoherence. We conclude that the transition to climate-friendly peatland usage requires coherent regulatory frameworks and incentive-based policies supporting rewetting. • We demonstrate the multi-sectoral and multi-level nature of peatland policies in the EU. • Agriculture, nature, water, and energy policies often impede horizontal coherence. • Conflicts between EU, national, and regional policies hinder vertical coherence. • Regulatory frameworks and incentive-based policies should be coherent. • Current incentive-based policy instruments are ineffective for emissions reduction. [ABSTRACT FROM AUTHOR]

Peatland drainage may degrade system resilience to high intensity, soil‐consuming fires. Peat soil fires are unique in that they can smoulder vertically through the soil column, with a multitude of consequences including large carbon emissions, altered hydrology, and dramatic shifts in vegetation communities. In this work we developed and verified a new method to model peat burn depths with readily available water level and peat hydraulic property data at the Great Dismal Swamp National Wildlife Refuge (VA and NC, USA). To model peat burn depths across 11 sites in the Great Dismal Swamp National Wildlife Refuge we combined water table time series data and soil moisture release curves, developed at multiple depths, with moisture‐to‐ignition thresholds. A subset of the results from this empirical modelling approach of peat burn depth severity were compared against those made using a mechanistic model of soil moisture, HYDRUS 1‐D. By comparing modelled burn depth potentials between these two approaches for a range of peats, we confirmed that our simpler, water table‐based approach had similar performance to HYDRUS 1‐D in drained and degraded peats, like those found in the Great Dismal Swamp National Wildlife Refuge. A comparative analysis of modelled burn depths across our study site found that water table position and peat water holding capacity were the key governing controls on burn depth potential. Our findings suggest that drainage weakens both short‐ and long‐term controls on peat burn depths by reducing soil moisture and by decreasing peat water holding capacity. This new approach offers land managers with an additional tool for assessing risk while offering insight into the drivers of peatland wildfire severity. [ABSTRACT FROM AUTHOR]

Background: Drainage activities have caused widespread wetland loss, groundwater drawdown and impairment of ecosystem services. There are now several national programs for wetland restoration, primarily focused on reintroducing ecosystem services such as habitats and nutrient retention. In Sweden, recent dry summers have also reinforced interest in hydrological functions such as the potential for enhanced groundwater storage, both in and around the wetland. However, there are several knowledge gaps regarding groundwater storage effects of restoration, including if they extend beyond the wetland and how they vary with local conditions. Therefore, we have systematically reviewed groundwater storage effects from the interventions of restoring, constructing or draining boreo-temperate wetlands. Drainage was included primarily to evaluate to what degree restoration can reverse drainage effects. Methods: We searched 8 databases for scientific journal publications in English, Swedish, Norwegian, Danish, French, German and Polish. Gray literature was searched in English and Swedish. Articles were included based on their relevance for Swedish conditions, i.e., in previously glaciated areas with boreal or temperate climate. Extracted outcome data were groundwater level changes, along with other variables including type of wetland and intervention and, when reported, distance between sampling point and intervention. Meta-analyses were conducted separately for studies that reported groundwater levels at different distances and studies that reported overall effects. Included studies were subject to critical appraisal to evaluate their susceptibility to bias, primarily selection bias, performance bias, and detection bias. Critical appraisal results were used in sensitivity analysis. Review findings: Out of 11,288 screened records, 224 articles fulfilled the criteria, and from these, 146 studies were included in meta-analysis. Most studies (89%) investigated peatlands, primarily from Finland, the UK and Canada. Restoration and drainage studies were equally common. Only nine studies reported measurements beyond the wetland area. Our synthesis is therefore primarily focused on effects within wetlands. In peatland restoration, the observed groundwater level rise decreased exponentially with distance from the restored ditch and was reduced to 50% after 9 [95% confidence interval: 5, 26] m. Drainage reached somewhat farther, with 50% of the groundwater drawdown remaining at 21 [11, 64] m. On average, restoration increased groundwater levels by 22 [16, 28] cm near the intervention, whereas drainage caused a drawdown of 19 [10, 27] cm. Assuming that sampling was unbiased, effects were similar for bogs, fens and mires. Restricting the meta-analysis to the 58% of studies that were of high validity did not alter conclusions. Conclusions: Effects of peatland restoration and drainage were of similar magnitudes but opposite directions. This indicates that, on average, rewetting of drained peatlands can be expected to restore groundwater levels near the ditch. However, restoration may not reach all the area affected by drainage, and there was a strong dependence on local context. For managers of wetland projects, it is thus important to follow up and monitor restoration effects and reinforce the intervention if necessary. Our results also point to a need for better impact evaluation if increased storage beyond the restored wetland area is desired. [ABSTRACT FROM AUTHOR]

Purpose: Peat extraction rapidly removes carbon from the peatland carbon store and furthermore leads to substantial losses of carbon from the extraction site by stimulating decomposition and erosion. Aim of this study is to evaluate whether the Product Environmental Footprint (PEF) approach is suitable for assessing the environmental impacts of white and black peat used in growing media as well as to provide generic data collected from growing media producers and the scientific literature. It is not the aim of this study to compare different land use options for peatlands. Method: PEF is developed in order to make environmental product declaration claims more reliable, comparable and verifiable across the EU, and to increase consumer confidence in eco-labels and environmental impact information. For PEF-compliant studies all land use activities must be considered. For peat extraction either pristine peatland or previously drained peatland used for forestry or agriculture has to be transformed. Hence, the suitability of land use-related PEF indicators is also investigated. Results: Diesel consumed for peat extraction, electricity used for peat processing and transport are the main contributors to acidification. Fuel production and consumption are the main contributors to human toxicity, with heavy metals to air and freshwater the contributing emissions. Ionising radiation, ozone depletion and resource depletion of minerals and metals are mainly caused by the electricity used. Climate change increased from 26 kg CO2eq per m3 processed white peat to 51 kg CO2eq per m3 processed black peat. The use of peat causes substantially higher GHG than the previous life cycle stages combined; white peat causes approximately 183 kg CO2eq per m3 and black peat 257 kg CO2eq per m3. Conclusions: Environmental impacts caused by peat are variable and depend on a number of spatial and temporal factors. Although most indicators used for PEF are suitable for assessing peat systems, that does not apply for the land use indicator and is at least questionable for the water use indicator, respectively, its weighting factor. Consequently, it is neither possible to identify the most relevant impact categories based on normalised and weighted results nor to calculate an overall single score for peat containing growing media. Since normalisation and weighting are mandatory steps for PEF conform impact assessment, the current PEF approach is not suitable to assess peat as intermediate product without adaptation of the land use indicator. [ABSTRACT FROM AUTHOR]

The artificial drainage and climate drying induced water table decline has resulted in large peat carbon and nitrogen (C&N) loss in peatlands, however, the effects of water table decline on C&N and microbe dynamics at different peat depths are not clear, as well as the effects of plant change and the restoration effects of rewetting. Here we selected a series of sites from undrained (NP), moderate-drained (MDP), deep-drained (DDP) to rewetted (RP) peatlands to study the variations in plants, C&N sequestration, stable isotopic abundances (δ13C and δ15N) and microbial communities at different depths. We found peatland drainage caused moderate degradation in the plant community, and litter greatly preserved the C&N in the 0–10/20 cm peat. Changes in C&N contents, δ13C and δ15N showed MDP had serious C&N loss in both the surface and part of subsurface peat (0-50 cm), and DDP caused more significant C&N loss in the subsurface peat (30-70 cm) than the surface peat (0-30 cm). Drainage changed the bacterial composition: oligotrophs (Acidobacteria) mostly increased, while copiotrophs (Proteobacteria and Bacteroidetes) mostly decreased. The stronger drainage the severer microbe changes, with serious changes in the subsurface peat rather than the surface peat; bacterial metabolic pathways exhibited similar patterns, and the changed pathways were mostly related to C&N metabolism. Long-term rewetting restored the surface C&N contents, δ13C and δ15N to the NP level with plant and litter recovery, whereas, the C&N contents and most of δ13C and δ15N in the subsurface peat were still significantly different from NP. RP had similar bacterial composition, diversity and metabolic pathways as NP in the surface peat, but the similarities between the subsurface microbes were very low. In addition, the taxonomic change, Shannon and Simpson indices of bacterial communities were significantly correlated with peat C&N dynamics during drainage and rewetting, and there were nine phyla dominantly relating to the peat C&N dynamics. Thus, the drainage caused C&N loss and microbial degradation were closely related, which were hard to be restored in the subsurface peat by the long-term rewetting. These indicated the peatlands with severe drainage or drying may consequently lose the stably restored subsurface C&N for a long-term and may have important implications with respect to climate change. [ABSTRACT FROM AUTHOR]

Peatlands are globally significant C storage because waterlogged conditions slow down organic matter (OM) decomposition. Changes in the water table (WT) because of global warming or drainage, consecutive vegetation succession, and enhanced root exudation causing priming may transform peatlands from C sinks to sources. We studied how glucose addition, WT, and forest harvesting affect the chemical composition of peat and decomposition rate by incubating peat columns collected from drained clear‐cut (CC) and forested (FD) peatlands. Columns were divided into high or low WT, and half were labeled with 13C to study the priming effect on peat decomposition and peat chemical quality. We measured CO2 fluxes, peat OM, and water quality. There was no detectable priming effect after glucose addition. Lowering of the WT led to increased CO2 efflux, which during the measurements averaged between 39 and 291 μg m–2 s–1. Low WT also decreased the proportion of water‐soluble OM in CC areas but not in FD areas. The proportion of recalcitrant OM in surface peat was higher in forest than in clear cut. Forest management also affected the quality of dissolved OM in soil water, with CC showing higher concentrations of recalcitrant compounds. Decomposition and OM quality were governed by forest management practices and WT manipulation. In the future, the C sink capacity of forested peatlands will be regulated by changes in WT level, forest management, and quality of OM. Core Ideas: Glucose addition did not induce positive priming of OM in forested peatlands.Decreased WT level lead to increased CO2 fluxes from peat.Forest management affected both peat OM and water quality. [ABSTRACT FROM AUTHOR]

Peatlands, as a type of ecosystem, are widely accepted to contribute to biodiversity, climate regulation, and human well-being. In comparison, it is reported that mismanagement of peatlands has resulted in a decline in environmental quality. To overcome this obstacle, the government should continue to investigate various cultivating strategies that allow for rapid propagation in order to accomplish the peatland restoration goal as efficiently as possible. However, due to the involvement in land restoration operations that initially met with little support from peatland farmers, their socioeconomic situation warranted further investigation. Therefore, this study examined the socioeconomic values associated with agricultural operations. This study employed a qualitative descriptive method and was conducted in Tumbang Nusa Village, Jabiren Raya Regency, Central Kalimantan, Indonesia, a region prone to peatland fires. The data were collected via interviews with 45 key informants. Land ownership, plant species, farmer motivations, farmer income, the value of forests to peatland farmers, and their understanding of peatlands and management were all collected. The findings indicate that successful peatland cultivation and management have benefited the farmer community. Land tenure is divided into two categories for peatland farmers: those derived from a 2-hectare transmigration quota and those acquired through a sale process. They, in general, have a firm grasp on peatlands and how to manage them, despite past failures due to ineffective techniques. They grow both short- and long-term plants, with the majority motivated by a desire to increase income from peatland cultivation and management. They earn between USD 2,277 and USD 7,286.4 per year from agricultural and non-agricultural products, placing them in the category of high-income individuals. While farmers from Java and indigenous people manage peatlands differently, they share a common goal: preventing peatland fires so they can continue to reap the economic benefits of land management through farming. Finally, they believe that the forest is necessary for survival, believing that peatland forests must be protected in order to survive. However, this study demonstrates that they continue to require guidance and assistance with sustainable peatland management that takes into account the socioeconomic functions of peatlands, strikes a balance between environmental protection and local community development, and employs cutting-edge technologies. Finally, the implications of the study are discussed, along with several recommendations for future research. [ABSTRACT FROM AUTHOR]

Peatland habitats represent key environmental resources that are a critical component in climate change mitigation strategies. However, many of these environmental settings are facing significant levels of erosion and degradation which, over time, will result in the loss of these key environments. Traditional monitoring techniques for these settings require invasive methods, disrupting the natural environment and potentially leading to further losses if incorrectly administered. In this article, we provide a non-invasive, cost-effective alternative to peatland health monitoring through the implementation of low-cost hyperspectral imaging techniques. Using common peatland plant species as a proxy for underlying peat health, we monitor the spectral response of Sphagnum plants under varying degrees of water stress to document their spectral response under these conditions. For this research, we utilise a low-cost, semi-portable High-Resolution Hyperspectral Imager capable of resolving mm-scale targets in conjunction with the ultra-low-cost Hyperspectral Smartphone that represents a completely accessible fully field portable instrument allowing for rapid and accurate on-site measurements. Both instruments are shown to provide accurate and robust results, capturing subtle changes in spectral response prior to their appearance within visual datasets enabling the use of mitigation and restoration techniques before the onset of more damaging conditions. [ABSTRACT FROM AUTHOR]

In recent decades, catastrophic wildfire episodes within the Sumatran peatland have contributed to a large amount of greenhouse gas emissions. The El-Nino Southern Oscillation (ENSO) modulates the occurrence of fires in Indonesia through prolonged hydrological drought. Thus, assessing peatland vulnerability to fires and understanding the underlying drivers are essential to developing adaptation and mitigation strategies for peatland. Here, we quantify the vulnerability of Sumatran peat to fires under various ENSO conditions (i.e., El-Nino, La-Nina, and Normal phases) using correlative modelling approaches. This study used climatic (i.e., annual precipitation, SPI, and KBDI), biophysical (i.e., below-ground biomass, elevation, slope, and NBR), and proxies to anthropogenic disturbance variables (i.e., access to road, access to forests, access to cities, human modification, and human population) to assess fire vulnerability within Sumatran peatlands. We created an ensemble model based on various machine learning approaches (i.e., random forest, support vector machine, maximum entropy, and boosted regression tree). We found that the ensemble model performed better compared to a single algorithm for depicting fire vulnerability within Sumatran peatlands. The NBR highly contributed to the vulnerability of peatland to fire in Sumatra in all ENSO phases, followed by the anthropogenic variables. We found that the high to very-high peat vulnerability to fire increases during El-Nino conditions with variations in its spatial patterns occurring under different ENSO phases. This study provides spatially explicit information to support the management of peat fires, which will be particularly useful for identifying peatland restoration priorities based on peatland vulnerability to fire maps. Our findings highlight Riau's peatland as being the area most prone to fires area on Sumatra Island. Therefore, the groundwater level within this area should be intensively monitored to prevent peatland fires. In addition, conserving intact forests within peatland through the moratorium strategy and restoring the degraded peatland ecosystem through canal blocking is also crucial to coping with global climate change. [ABSTRACT FROM AUTHOR]

Central European raised bogs are valuable habitats inhabited by highly adapted peatland specialists, so-called tyrphobionts and tyrphotolerants. Many of them have been destroyed by drainage and peat extraction. After such strong disturbance, the entire biota is deeply influenced, and recovery to a pre-disturbance state may be limited. This study shows successional trends in the recovery of vegetation, fungi, and Lepidoptera in two disturbed raised bogs comparing with reference. After three decades of spontaneous development, the species composition did not match the reference natural bogs in any of the studied taxonomic groups; however, all groups responded in a very similar way to the disturbance. Alternative communities with low peatland specialists developed. Each taxonomic group was influenced by similar environmental factors, mostly by remaining peat, water table, and successional age, while successional age and pH were the most important factors for peatland specialists. If all species were considered, we found an increasing pattern in trophic specialisation during the succession. As successional age is one of the most important factor, restoration measures should be taken as soon as possible, otherwise the site will not be inhabited by peatland specialists. Generally, peatland specialists should be focused more on in restoration projects, but also dominant plant species are important because they are associated with most fungal and Lepidoptera species. Restoration will be more successful if a thicker layer of peat is left after peat extraction, and water table has returned to pre-draining conditions. [ABSTRACT FROM AUTHOR]

Harvesting of plantation conifers on peatlands is carried out as part of restoration and forestry operations. In particular, in the UK and Ireland, conifer plantations on drained ombrotrophic blanket and raised bogs are increasingly being removed (by harvesting), along with blocking of drainage ditches to help raise water tables to reinitiate and restore bog vegetation and function. However, both tree harvesting and peatland restoration operations can have significant impacts on water quality at local and catchment scales. Previous research has suggested that leaching from leftover decomposing brash (tree tops and branches, including wood and needles) is the primary cause, while other work has suggested that release from rewetted peat also contributes to water quality changes. This research investigates the relative importance of peat rewetting, needles and branches on water quality using mesocosm experiments, to help elucidate the mechanisms behind water quality changes following restoration and harvesting operations. Peat and brash were collected from a drained afforested blanket bog in the Flow Country, Scotland. Short-term mesocosm experiments were conducted by incubating peat, peat + needles and peat + needles + branches with rainwater in quadruplicate. Brash from Sitka spruce (Picea sitchensis) and lodgepole pine (Pinus contorta) was investigated separately, while we also conducted experiments with fresh and aged (∼18 months) brash. Peat, needles and branches all significantly impacted water quality in the order of branches > needles > peat, while concentrations of DOC, PO 4 3−, NH 4 +, K and Mn were most impacted. Water quality impacts of spruce brash appeared generally greater than pine, while fresh brash had larger effects than aged brash. In our mesocosms, relative contributions to water quality changes were estimated by elemental yields. On average, peat contributed 25.4% (range 0.6–72.3%), while needles and brash contributed 19.7% (range 3.0–37.0%) and 54.9% (range 22.1–70.2%) to yields, respectively. We further estimate that 267 kg C ha−1 (255.8 kg as DOC, 10.7 kg as DIC), 27.4 kg K ha−1, 5.8 kg P ha−1 (as PO 4 3−) and 0.5 kg N ha−1 (as NH 4 +) could be released from brash, over nine days. [Display omitted] • Relative contributions of peat, needles and branches to water quality were assessed. • DOC, PO 4 3−, NH 4 +, K and Mn were collectively the variables most impacted. • Contributions to leaching were peat (25.4%), needles (19.7%) and branches (54.0%). • Removal of needles and branches could help mitigate water pollution. [ABSTRACT FROM AUTHOR]

Domestic wastewater remains the main problem in solving environmental pollution. The type of treatment determines the domestic wastewater treatment procedure and the media used. The use of peat and coconut shell media in domestic wastewater treatment in developing countries with the morphology of peatland and tropical areas is of particular concern. The purpose of this study was to test the ability of the combination of peat and coconut shell media to reduce the pollution load of domestic wastewater disposed in student dormitories. The parameters used as indicators were biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), ammonia nitrogen (NH+4 –N), and pH. Testing of domestic wastewater treatment plants using a combination of peat and coconut shell media was carried out in three replications to measure domestic wastewater parameters for 42 d. The results showed that the domestic wastewater efflu- ent had a BOD of 159.1 mg L–1, COD of 310.39 mg L–1, TSS of 38, NH+ –N of 3.14, and pH of 8.21, on average. After applying a combination of peat and coconut shell media in a wastewater treatment plant, the results of domestic wastewater decreased to an average BOD of 49.31 mg L 4 –N of 3.14, and pH of 8.21, on average. After applying a combination of peat and coconut shell media in a wastewater treatment plant, the results of domestic wastewater decreased to an average BOD of 49.31 mg L –1, COD of 116.94 mg L–1, TSS of 4.19, NH+ 4 –N of 1.17, and pH of 6.69, and the level of efficacy of the removal was 66. 41% for BOD, 49.40% for COD, 80.58% for TSS, and 59.52% for NH+ 4 –N. [ABSTRACT FROM AUTHOR]

Peatlands are shaped by slow litter decomposition, but threshold decomposition rates that allow peat formation remain unclear. Can agroforestry in the tropics be compatible with paludiculture that allows peat formation? We explored the determinants of litter decomposition in wet agroforests adjacent to tropical peatlands in Central Kalimantan (Indonesia) by litterbag studies (up to 16 weeks) with standing litter sources to estimate rate constants, characterize litter quality (especially lignin (L), polyphenolics (Pp) and nitrogen (N)), and monitor temperature and groundwater levels. In litter transfer experiments we tested for home-field advantage (HFA) effects between land cover types. Mean residence times around 85 weeks at 27 °C were associated with a high (L + Pp)/N ratio. However, in the crossover treatments, mean residence times varied from 30 to 180 weeks and strong HFA effects (up to 80% faster decomposition at "home") were found when litter from other sources was tested in old fruit-based agroforests. HFA indicates a local decomposer community well-adapted to its normal litter diet. Litter residence times of around two years are below the apparent peat formation threshold. Maintaining wet agroforest conditions adjacent to peat domes supports peatland rewetting and restoration but does not contribute to on-site peat formation processes. [ABSTRACT FROM AUTHOR]

The article focuses on peat surface compression reduces smouldering fire potential as a novel fuel treatment for boreal peatlands.

Degraded and drained peat swamp forests (PSFs) are major sources of carbon emissions in the forestry sector. Rewetting interventions aim to reduce carbon loss and to enhance the carbon stock. However, studies of rewetting interventions in tropical PSFs are still limited. This study examined the effect of rewetting interventions on carbon dynamics at a rewetted site and an undrained site. We measured aboveground carbon (AGC), belowground carbon (BGC), litterfall, heterotrophic components of soil respiration (Rh), methane emissions (CH4), and dissolved organic carbon (DOC) concentration at both sites. We found that the total carbon stock at the rewetted site was slightly lower than at the undrained site (1886.73 ± 87.69 and 2106.23 ± 214.33 Mg C ha−1, respectively). The soil organic carbon (SOC) was 1685 ± 61 Mg C ha−1 and 1912 ± 190 Mg C ha−1 at the rewetted and undrained sites, respectively, and the carbon from litterfall was 4.68 ± 0.30 and 3.92 ± 0.34 Mg C ha−1 year−1, respectively. The annual average Rh was 4.06 ± 0.02 Mg C ha−1 year−1 at the rewetted site and was 3.96 ± 0.16 Mg C ha−1 year−1 at the undrained site. In contrast, the annual average CH4 emissions were −0.0015 ± 0.00 Mg C ha−1 year−1 at the rewetted site and 0.056 ± 0.000 Mg C ha−1 year−1 at the undrained site. In the rewetted condition, carbon from litter may become stable over a longer period. Consequently, carbon loss and gain mainly depend on the magnitude of peat decomposition (Rh) and CH4 emissions. [ABSTRACT FROM AUTHOR]

The supply of clean water is a major problem in both developed and developing countries. The abundant amount of peat water can be a potential source of clean water in areas with peatlands. Peat water treatment can be conducted effectively and efficiently by integrating various existing methods, such as aeration, sedimentation, and filtration using shell sand and activated carbon. The results show that the parameters of color, turbidity, Ferrum (Fe), microbiological parameters, and pH of peat water can be conditioned according to clean water standards. The average peat watercolor parameter before processing is 866.7 PtCo, 10.96 NTU turbidity, 2.48 mg L–1 Fe, Fe, 4.30 pH, and coliform (microbial) peat water at 1068 CFU and after passing the color combination treatment to 28.83 PtCo, turbidity 2.19 NTU, Fe 0.22 mg L–1, and coliform 20 CFU and pH 6.83. Integrated peat water treatment is the most effective at the filtration and adsorption stages. [ABSTRACT FROM AUTHOR]

The boreal region is a significant peat‐forming area. With peat, there lie other natural resources, including mineral ores and fossil fuels needed by our economy. However, mining for mineral resources or any other activity that leads to large‐scale groundwater extraction in the near vicinity or underneath the mires can alter the water levels in the overlaying ecosystems and thus have a damaging effect on them, raising concerns about the mires' preservation. Peat itself may isolate surface vegetation from drainage caused by nearby mining when its hydraulic conductivity is sufficiently low. More is known about the hydraulic properties of the uppermost layers of the peat column, but there is very little data about deeper, generally more decomposed peat layers that may potentially act as drainage barriers. Carrying out in situ hydraulic conductivity tests in less conductive peat can be laborious and time‐consuming, and not always practical. This research aims to study and verify statistical relationships between easy‐to‐measure peat properties and hydraulic conductivity over the entire peat column, covering the knowledge deficit that is important in the context of indirect drainage effects related to mining or any other large‐scale groundwater extraction. For that, we sampled peat and conducted in situ saturated hydraulic conductivity tests in several mires in northeast Estonia to gather information about the hydraulic properties of boreal peat. Collected data were fitted with linear mixed‐effects models to link hydraulic conductivity with the degree of decomposition, dry bulk density, depth of measurement, and peatland growth phase. The results indicate that these parameters are strongly correlated with saturated hydraulic conductivity and can serve as predictors of this parameter. Constructed statistical models exhibit relatively high explanatory power and show potential usage for characterizing the hydraulic conductivity of peat. The findings of this study may be helpful in the efforts of mire conservation. [ABSTRACT FROM AUTHOR]

Summary: Forty percentage of UK peatlands have been drained for agricultural use, which has caused serious peat wastage and associated greenhouse gas emissions (carbon dioxide (CO2) and methane (CH4)). In this study, we evaluated potential trade‐offs between water‐table management practices for minimizing peat wastage and greenhouse gas emissions, while seeking to sustain romaine lettuce production: one of the most economically relevant crop in the East Anglian Fenlands. In a controlled environment experiment, we measured lettuce yield, CO2, CH4 fluxes and dissolved organic carbon (DOC) released from an agricultural fen soil at two temperatures (ambient and +2°C) and three water‐table levels (−30 cm, −40 cm and −50 cm below the surface). We showed that increasing the water table from the currently used field level of −50 cm to −40 cm and −30 cm reduced CO2 emissions, did not affect CH4 fluxes, but significantly reduced yield and increased DOC leaching. Warming of 2°C increased both lettuce yield (fresh leaf biomass) and peat decomposition through the loss of carbon as CO2 and DOC. However, there was no difference in the dry leaf biomass between the intermediate (−40 cm) and the low (−50 cm) water table, suggesting that romaine lettuce grown at this higher water level should have similar energetic value as the crop cultivated at −50 cm, representing a possible compromise to decrease peat oxidation and maintain agricultural production. [ABSTRACT FROM AUTHOR]

Dissolved organic carbon is an additional path of carbon cycle but there is a lack of information about its distribution in peatland and rates of downward movement. We dated seven peat cores (separately the dissolved (DOC) and particulate (POC) organic carbon) from Mukhrino peatland (typical zonal oligotrophic bog) in western Siberia to assess the date distribution between those two peat fractions. Our results revealed that the DOC is younger than POC for the surface peatland layers (0-150 cm) and older for the deeper layers. The date differences increases with depth and reaches 2000-3000 years at the bottom layer (430-530 cm). In our hypothesis this date discrepancy caused by more young DOC moving to the deeper and older peat layers. The estimated average value of DOC downward movement was 0.047±0.019 cm yr-1. Th oldest dates found at the lake bottom and ancient riverbed were 10 053 and 10 989 cal yr BP correspondingly. For the whole period of peatland functioning the average peat accumulation rate was estimated as 0.067±0.018 cm yr-1 (0.013-0.332 cm yr-1), the carbon accumulation rate was estimated as 38.56±12.21 g C m-2 yr-1 (28.46-57.91 g C m-2 yr-1). [ABSTRACT FROM AUTHOR]

Peat deposits of the Muara Siran, East Kalimantan area, were investigated for their vertical and lateral succession, to examine the characteristic variability, particularly its macro- and microtextures. The deposits are situated in the Kutai Basin, in the vicinity of several Cenozoic coal deposits. Peat samples were taken from twenty-seven coring sites in the area, using a MacCaulay peat corer. The Muara Siran peatlands lie between the Kedang Kepala and Belayan Rivers. Siran Lake lies between these rivers and within the peat system. The peat thickness varied from 0.5 m to 12 m. Decomposed sapric peat formed the basal and margins of the deposit, overlain by moderatelydecomposed hemic peat in the central part of the peatlands, though both sapric and hemic peat types are interbedded at the margins of the mire. The fibric peat types were found mostly at the top of the mire and only distal from any active streams. Twenty-four samples of peat were freeze-dried for petrographic analyses of both plant part and maceral analyses using a reflected microscope. On the average, the dominant plant parts were stems and wood (i.e. secondary xylem). Maceral composition was mostly from the huminite group (on the average 89%), particularly the macerals humodetrinite and textinite. Macroscopic peat type and microscopic composition are linked. Fibric peat was found to be rich in wood and textinite. Hemic was mostly composed of stems and wood with textinite and humodetrinite as the most abundant macerals. Sapric peat has near equal proportions of stems, wood, and macerated tissue. Humodetrinite is the most abundant maceral in sapric. The average ash and sulfur content were low, 1.29 wt.% and 0.11 wt.%, respectively. Understanding the physical characteristics of inland peat as in Muara Siran peatland is essential to build knowledge of how inland peat is formed and what makes it different from coastal peat. Muara Siran is a unique, relatively small peatland in the central eastern Kalimantan which is still considerably pristine, hence may serve the aim of this study well. [ABSTRACT FROM AUTHOR]

The focus of current water management in drained peatlands is to facilitate optimal drainage, which has led to soil subsidence and a strong increase in greenhouse gas (GHG) emissions. The Dutch land and water authorities proposed the application of subsoil irrigation (SSI) system on a large scale to potentially reduce GHG emissions, while maintaining high biomass production. Based on model results, the expectation was that SSI would reduce peat decomposition in summer by preventing groundwater tables (GWTs) from dropping below - 60 cm. In 2017–2018, we evaluated the effects of SSI on GHG emissions (CO 2 , CH 4 , N 2 O) for four dairy farms on drained peat meadows in the Netherlands. Each farm had a treatment site with SSI installation and a control site drained only by ditches (ditch water level - 60 / - 90 cm, 100 m distance between ditches). The SSI system consisted of perforated pipes - 70 cm from surface level with spacing of 5–6 m to improve drainage during winter–spring and irrigation in summer. GHG emissions were measured using closed chambers every 2–4 weeks for CO 2 , CH 4 and N 2 O. Measured ecosystem respiration (Reco) only showed a small difference between SSI and control sites when the GWT of SSI sites were substantially higher than the control site (> 20 cm difference). Over all years and locations, however, there was no significant difference found, despite the 6–18 cm higher GWT in summer and 1–20 cm lower GWT in wet conditions at SSI sites. Differences in mean annual GWT remained low (< 5 cm). Direct comparison of measured N 2 O and CH 4 fluxes between SSI and control sites did not show any significant differences. CO 2 fluxes varied according to temperature and management events, while differences between control and SSI sites remained small. Therefore, there was no difference between the annual gap-filled net ecosystem exchange (NEE) of the SSI and control sites. The net ecosystem carbon balance (NECB) was on average 40 and 30 t CO 2 ha -1 yr -1 in 2017 and 2018 on the SSI sites and 38 and 34 t CO 2 ha -1 yr -1 in 2017 and 2018 on the control sites. This lack of SSI effect is probably because the GWT increase remains limited to deeper soil layers (60–120 cm depth), which contribute little to peat oxidation. We conclude that SSI modulates water table dynamics but fails to lower annual carbon emission. SSI seems unsuitable as a climate mitigation strategy. Future research should focus on potential effects of GWT manipulation in the uppermost organic layers (- 30 cm and higher) on GHG emissions from drained peatlands. [ABSTRACT FROM AUTHOR]

The Mauritia flexuosa palm swamp forest (aguajales) are considered the main Amazonian tropical peatlands that contribute to the maintenance of biodiversity and the hydrological cycle, in addition to their considerable contribution in carbon sequestration and storage. Through an exhaustive literature review and field observations we identify the importance, threat factors and opportunity for these ecosystems. The peatlands store more than twice as much carbon as all the world’s forests together and form a target group for the study of climate change. Access to non-destructive extraction systems for the harvest of fruits must be articulated with socio-economic development plans. The application of participatory environmental education policies and economic incentives to the communities that protect these valuable territories is a priority. [ABSTRACT FROM AUTHOR]

Aerobic methanotrophs are crucial in ombrotrophic peatlands, driving the methane and nitrogen cycles. Peat mining adversely affects methanotrophs, but activity and community composition/abundances may recover after restoration. Considering that the methanotrophic activity and growth are significantly stimulated in the presence of other microorganisms, the methane-driven interaction network, which encompasses methanotrophs and nonmethanotrophs (i.e., the methanotrophic interactome), may also be relevant in conferring community resilience. Yet, little is known of the methanotrophic interactome's response to and recovery from disturbances. Here, we determined the recovery of the methanotrophic interactome as inferred by a co-occurrence network analysis comparing pristine and restored peatlands. We coupled a DNA-based stable isotope probing (SIP) approach using [ 13C]CH4 to a co-occurrence network analysis derived from the 13C-enriched 16S rRNA gene sequences to relate the response in methanotrophic activity to the structuring of the interaction network. Methanotrophic activity and abundances recovered after peat restoration since 2000. "Methylomonaceae" taxa were the predominantly active methanotrophs in both peatlands, but the peatlands differed in the relative abundances of Methylacidiphilaceae and Methylocystis. However, bacterial community compositions were distinct in both peatlands. Likewise, the methanotrophic interactome was profoundly altered in the restored peatland. Structuring of the interaction network after peat mining resulted in the loss of complexity and modularity, indicating a less connected and efficient network, which may have consequences in the event of recurring/future disturbances. Therefore, determining the response of the methane-driven interaction network, in addition to relating methanotrophic activity to community composition/abundances, provided a more comprehensive understanding of the resilience of the methanotrophs. [ABSTRACT FROM AUTHOR]

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Context: An increased interest in the restoration of peatlands for delivering multiple benefits requires a greater understanding of the extent and location of natural and artificial features that contribute to degradation. Objectives: We assessed the utility of multiple, fine-grained remote sensing datasets for mapping peatland features and associated degraded areas at a landscape-scale. Specifically, we developed an integrated approach to identify and quantify multiple types of peatland degradation including: anthropogenic drainage ditches and peat cuttings; erosional gullies and bare peat areas. Methods: Airborne LiDAR, CASI and aerial image datasets of the South West UK, were combined to identify features within Dartmoor National Park peatland area that contribute to degradation. These features were digitised and quantified using ArcGIS before appropriate buffers were applied to estimate the wider ecohydrologically affected area. Results: Using fine-scale, large-extent remotely sensed data, combined with aerial imagery enabled key features within the wider expanse of peatland to be successfully identified and mapped at a resolution appropriate to future targeted restoration. Combining multiple datasets increased our understanding of spatial distribution and connectivity within the landscape. An area of 29 km2 or 9.2% of the Dartmoor peatland area was identified as significantly and directly ecohydrologically degraded. Conclusions: Using a combination of fine-grained remotely sensed datasets has advantages over traditional ground survey methods for identification and mapping of anthropogenic and natural erosion features at a landscape scale. The method is accurate, robust and cost-effective particularly given the remote locations and large extent of these landscapes, facilitating effective and targeted restoration planning, management and monitoring. [ABSTRACT FROM AUTHOR]

• Gamma ray data alone proved insufficient in predicting peat depth. • Terrain attributes like elevation can provide complementary information. • Regression kriging significantly improved the model performance. • Empirical Bayesian kriging regression performed the best. Pristine peatlands being excellent storage for terrestrial Carbon (C) play a crucial role in regulating climate and water and provide several important ecosystem services. However, peatlands have been heavily altered (e.g., by draining the water table), increasing greenhouse gas (GHG) emissions. Restoring peatlands requires a comprehensive characterization, including knowledge of peat depth (PD; m). Traditionally, this requires the physical insertion of a push probe, which is time-consuming and labor-intensive. It has been shown that non-invasive proximal sensing techniques such as electromagnetic induction and ground penetrating radar can add value to PD data. In this research, we want to assess the potential of proximally sensed gamma-ray (γ-ray) spectrometry (i.e., potassium [K], thorium [Th], uranium [U], and the count rate [CR]) and terrain attributes data (i.e., elevation, slope, SAGAWI, and MRVBF) to map PD either alone or in combination across a small (10 ha) peatland area in ØBakker, Denmark. Here, the PD varies from 0.1 m in the south to 7.3 m in the north. We use various prediction models including ordinary kriging (OK) of PD, linear regression (LR), multiple LR (MLR), LR kriging (LRK), MLR kriging (MLRK) and empirical Bayesian kriging regression (EBKR). We also determine the minimum calibration sample size required by decreasing sample size in decrements (i.e., n = 100, 90, 80,..., 30). We compare these approaches using prediction agreement (Lin's concordance correlation coefficient; LCCC) and accuracy (root mean square error; RMSE). The results show that OK using maximum calibration size (n = 108) had near perfect agreement (0.97) and accuracy (0.59 m), compared to LR (ln CR; 0.65 and 0.78 m, respectively) and MLR (ln K, Th, CR and elevation; 0.85 and 0.63 m). Improvements are achieved by adding residuals; LRK (0.95 and 0.71 m) and MLRK (0.96 and 0.51 m). The best results were obtained using EBKR (0.97 and 0.63 m) given all predictions were positive and no significant change in agreement and standard errors with the decrement of calibration sample size (e.g., n = 30). The results have implications towards C stocks assessment and improved land use planning to control GHG emissions and slow down global warming. [ABSTRACT FROM AUTHOR]

• Burnt peatlands had the greatest subsidence of all studied land-uses. • There were significant changes in peat physico-chemical properties with land-use change from forest. • Peat subsidence positively correlated with reduction in water table level. • No significant difference in total peat CO 2 emissions between different land-uses. • CH 4 emissions were positively correlated with high water table level. Tropical peatlands are globally important ecosystems for carbon storage, biodiversity conservation, water storage and regulation, and several other valuable ecosystem services. Despite their importance, peatlands in Southeast Asia have been heavily degraded by anthropogenic disturbances such as drainage, agricultural conversion, and fire. In this spatially extensive study we characterised peat properties, nutrient concentrations, surface subsidence rates and greenhouse gas emissions from peatlands of Selangor, Peninsular Malaysia under different land-uses: Secondary Forest, Fire affected and replanted forest (Burnt), Pineapple Plantation, Mixed Agriculture, Smallholder Oil Palm Monoculture, and Industrial Oil Palm Monoculture. All the measured peat physico-chemical properties and nutrient concentrations were significantly different between land-uses. Principal component analyses indicated that peat under the Mixed Agriculture and Burnt land-uses showed the greatest degree of modification relative to peat under the Secondary Forest land-use. Burnt land-use also showed a significantly higher subsidence rate (4.4 ± 1.2 cm yr−1) than all the other land-uses (ranging between 1.8 ± 0.47 and 3.2 ± 0.5 cm yr−1). Water table was significantly higher at the Burnt land-use (-26 cm) than all other land-uses, likely reflecting fire-prevention drain blocking measures as well as lower land surface heights post fire. Smallholder oil palm land-use had the lowest water table (−68 cm), while water table level in all other land-uses did not significantly differ from that of Secondary Forest (−43 cm). Peat surface level changes were positively related to increase in drainage, showing the importance of maintaining a high water table level in reducing peat degradation and carbon loss from peatlands. Total CO 2 (mean range 492 to 1019 mg m−2 hr-1) and CH 4 emissions (mean range 637 to 1422 µg m−2 hr-1) did not significantly differ between land-uses or seasons. CH 4 emissions were negligible under all land-uses and higher emissions were correlated with a higher water table level. Taken together, the results show that anthropogenic land-use change impacts the physico-chemical properties and nutrient content of peat, and that increased drainage alongside changes in other peat properties leads to increased peat subsidence and carbon loss. [ABSTRACT FROM AUTHOR]

The relationship between the small‐scale distribution pattern of bryophyte biomass on restored milled peatlands and substrate properties (e.g. moisture, pH, nutrients, and their ratios) was studied. Substrate properties may determine the species composition of bryophyte communities that have developed in such areas. Two experimental sites were established in northern Estonia where the moss‐layer‐transfer technique had been used for the revegetation of abandoned peatfields for almost a decade before sampling. Diaspores of Sphagnum species common on bogs were distributed in these sites. After 7 years one site was mainly dominated by Sphagnum whereas true mosses (Polytrichum strictum, Aulacomnium palustre, and Pleurozium schreberi) were abundant in the other site. Three moss groups were distinguished: Sphagnum, P. strictum, and other mosses based on cluster analysis. The biomass of Sphagnum was related to peat moisture and potassium content. For P. strictum the N/K ratio was important, and the production of A. palustre grew with the increase in the N/P ratio of peat. It was concluded that peat properties played an important role in the formation and development of bryophyte communities on revegetated peatfields on a small scale (<0.1 ha). [ABSTRACT FROM AUTHOR]

[Display omitted] • Industrialization and urbanization cause higher atmospheric metal emissions in China. • China reports potentially toxic elements (PTEs) and black carbon (BC) in peat bogs. • Ombrotrophic peat adsorbs POPs due to its high organic matter content. • Major PAH sources shifted from local to remote due to high pollution regions in S. Asia. • Future research perspectives and direction on peat geological archives. Ombrotrophic peat bogs are widely characterized by precipitation-dependent wetlands where nutrient supply is derived from atmospheric deposition (including snowfall and air dust). These bogs serve as active information storage systems, continuously recording atmospheric environmental changes. In China, peat record show dating back to the commencement of industrialization era and show an increase in environmental pollutants, with an unprecedented increase over the last 50 years. In NE China, long-distance high-altitude winds carry dust from Mongolia and Western China, whereas in SW China, dust mainly comes from the desert, Loess Plateau, and adjacent Qinghai Tibet Plateau, with contribution rates of 45%, 22%, and 33%, respectively. Increased anthropogenic activities (smelting and extensive coal burning) led to increased PTEs emissions, which peaked during the Industrial Revolution. After the foundation of New China in 1949, combustion-generated pollutant emissions increased sharply and accelerated during the 1980s. However, some peat cores show decline in the last two decades, reflecting strict control measures that led to reductions in biomass burning and coal consumption. This review briefly summarizes the dating of peatlands and their depositional archives of several environmental pollutants and their sources in China. It also highlights some areas of improvement and recommends further research perspectives on peat archives to improve our understanding of atmospheric environment changes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Transpiration and evaporation were estimated at three tropical peat swamp sites. • Partitioning evapotranspiration based on conductance is the most appropriate. • Haze and soil drying significantly affected transpiration and evaporation. • Transpiration was reduced by drainage but restored by tree acclimation. • El Niño reduced evaporation and transpiration during the dry season. Disturbances in tropical peat swamp forests greatly impact water transport into the atmosphere through evapotranspiration (ET). However, transpiration (T) and evaporation (E) are affected by disturbances in different manners. Based on eddy fluxes and meteorological data, we used three methods to estimate T and E separately at three tropical peat swamp forest sites with different degrees of disturbance. Each method utilizes the i) water use efficiency, ii) linear relationship between ET and gross primary production, and iii) conductance of T and E in each. The results showed that the conductance method was the most reasonable for estimating T and E. The other two methods could not be applied because of the large variance in the water use efficiency and lack of a strong relationship between ET and gross primary production, among other reasons. Inter-site comparisons suggested that lowering the groundwater level (GWL) reduced T , but T subsequently recovered. This was likely because the trees acclimated to the dry environment. There was no clear difference in E among the three sites under conditions of lower GWLs. The mean T /ET in the almost undisturbed forest (0.60) was greater than that at the burned site with sparse vegetation (0.21). Overall, El Niño events decreased both T and E during the dry season at all sites. In the almost undisturbed forest, T and E decreased by 1.14 and 0.27 mm day−1, respectively. During El Niño events, precipitation decreased to near zero, fire sizes increased, and the downward photosynthetic photon flux density decreased. The decreases in T and E were mainly due to attenuation of incoming radiation by the fire-induced haze. In addition, significant soil desiccation due to lowered GWL impaired root water uptake, resulting in decreased T. In addition, E was decreased by soil surface drying. However, the direct effect of further atmospheric drying on E and T was small during the dry season. Our results show that both drainage and El Niño events reduced T and E in different manners. [ABSTRACT FROM AUTHOR]

• DigiBog was modified to consider snow cover and short growing seasons. • The model performs well, with error in simulated peat thickness as low as 26 cm. • Simulated peat accumulation is sensitive to water stored on the peat surface. DigiBog is a numerical model that simulates peat accumulation in temperate peatlands. Here, we modify DigiBog for boreal peatlands (DigiBog_Boreal) by accounting for snow cover, short growing seasons and groundwater exchanges between the peat and the aquifer. DigiBog_Boreal is then used to replicate ∼6500 years of peat accumulation at two high boreal latitude peatlands in Quebec, Canada. DigiBog_Boreal was driven with a weather generator and climate models, while peat cores from the sites were used to develop initial conditions and calibrate DigiBog_Boreal. Our results demonstrate that DigiBog_Boreal can replicate well peat thickness and age-depth profiles but cannot produce long-term fluctuations in water-table depths. Here, a possible explanation for DigiBog_Boreal's underperformance is the stability in the climatic drivers and less likely the new model developments. The results also indicate that peat decomposition and accumulation in DigiBog_Boreal are sensitive to water stored on the peat surface. [ABSTRACT FROM AUTHOR]

Wildfire is the largest disturbance affecting northern peatlands; however, little is known about how burn severity (organic soil depth of burn) alters post-fire hydrological conditions that control the recovery of keystone peatland mosses (i.e. Sphagnum). For this reason, we assessed the impact of burn severity on moss water availability by measuring soil tension ( Ψ) and surface volumetric moisture content ( θ) in burned and unburned portions of a peatland complex 2 years after fire. We found that both high and low burn severity decreased post-fire water availability by altering peat hydrophysical properties (moisture retention and water repellency). Locations covered by Sphagnum fuscum prior to fire exhibited a decreasing post-fire water availability with an increasing burn severity. In contrast, the lowest water availability ( Ψ > 400 cm, θ < 0·02) was observed in feather mosses that underwent low burn severity (residual branches identifiable). Deep burning (>0·20 m) in peatland margins and burn depths >0·05 m in the middle of the peatland exhibited the highest water availability ( Ψ < 60 cm). Locations with low surface θ and high Ψ, notably feather mosses undergoing low burn severity, exhibited minimal moss recolonization. Such areas dominate post-fire surface cover (~40%) within late successional (mature) peatlands or peatlands located in dry hydrological settings. We argue that such environments are under-represented in conceptual models of post-fire recovery. A new conceptual model is proposed in which (1) deep burning is counterbalanced by rapid recolonization and (2) pre-fire species interact with burn severity to produce substantial lags in post-fire moss recovery. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]