•Peatland can serve as archive of local smelting activity in the Brynica River catchment.•Magnetic signal is highly correlated with Pb content along the study peat profiles.•The strongest magnetic ...signal and Pb content is related to medieval mining activity.
One of the oldest areas of ore mining in Upper Silesia (southern Poland) is Miasteczko Śląskie, which is surrounded by numerous peat bogs developed in the Brynica Valley. These can offer a good alternative to standard archaeological investigations because they are valuable archives of climatic and anthropogenic impacts. The main aim of this study was to detect traces of human activity and historical mining and smelting in the Brynica River catchment using a combination of magnetic, radiometric and geochemical methods. The research was conducted on two peat profiles: Moczydła and Żyglinek. The application of mass-specific magnetic susceptibility (χ), the determination of the content of heavy metals (Pb, Cu, Zn, Cd, Fe) and radiocarbon dating allowed for investigation into the distribution of anthropogenic pollutants in the peat profile. Additionally, the enrichment factor (EF) of selected heavy metals was calculated. The results revealed the potential mobility of Cu, Zn and Cd in peat profiles and the lack of Pb mobility. Maximum enrichment of Pb could be observed in the Moczydła profile at a depth of 17 cm (5,996 mg kg−1) and in the Żyglinek profile at a depth of 14 cm, where it amounted to 287 mg kg−1 and dated back to the period 1300–1600 AD. However, in the Żyglinek profile a noticeable increase in the value of χ could be seen from a depth of 40 cm, where peat layers corresponded to 2700 BC. The high correlation observed between anthropogenic Pb (EFPb) and magnetic parameters (χ and χ/Fe) will be useful for the further study of the tracers of ore mining and smelting and other historical human impacts on the environment. It can support archaeological studies conducted at the sites of early settlements, which in Central and Northern Europe were very often located on hills surrounded by swamps and peat bogs.
Field data of topography, water levels, and peat hydraulic conductivity collected over a 28‐year period have revealed the impacts of marginal drainage on uncut raised bog ecohydrology and its peat ...properties. Drainage of the regional groundwater body has induced changes in the hydraulic properties of deep peat, with peat compression decreasing hydraulic conductivity and storativity while simultaneously introducing localized secondary porosity and effective storage. Where peat has increased in hydraulic conductivity, there is a corresponding decline in vertical hydraulic gradients and significant localized increases in recharge to the underlying substrate. Repeated topographic surveys show intense localized areas of peat consolidation (>5%) where it is underlain by highly permeable (>10 m/day) glacial till deposits. More widely, continued subsidence (4–6 mm/year) of the bog surface has been measured over 900 m from the bog margin, resulting in the progressive loss of approximately 40% of actively growing raised bog since 1991. This loss has thus been shown to be attributable to changes in the underlying groundwater head due to deep‐cut drainage, rather than near‐surface peatland drainage. However, although reinstating regional hydrostatic pressures in order to restore this ombrotrophic peatland may control the rapid drainage through preferential flow pathways, this may not eliminate the ecological impacts resulting from changed surface morphology arising from subsidence. Hence, this longitudinal study provides new insights into the role that aquifer systems and groundwater bodies play in maintaining hydrogeological processes in ombrotrophic peatland systems, while highlighting the difficulty in ecological restoration where regional groundwater dependencies are significant.
Key Points
Quantification of the impact of marginal drainage on peat hydrogeological properties, groundwater heads and surface ground level
Peat consolidation (>5%) most intense where it is underlain by highly permeable (>10 m/day) glacial till deposits
New insights on the role of groundwater as an environmental supporting condition in ombrotrophic raised bog ecosystems
•The steady state and dynamic BOG re-liquefaction techniques are analyzed and compared in this research.•The existing steady-state simulation techniques are summarized and analyzed from three ...aspects: structure, parameters and optimization methods.•This paper analyzes the technology of dynamic simulation and points out the opportunities and difficulties in the future development of BOG dynamic simulation.•The existing system evaluation parameters are summarized and the system is analyzed from the comprehensive point of view.
Over the past few years, liquefied natural gas (LNG) evaporated gas re-liquefaction technology has rapidly developed. This technology is particularly useful in trans-oceanic LNG trade, which has grown to be a hot sector in the world’s energy trade. And there are several limitations on board. Reducing energy consumption, improving efficiency, and lowering costs are crucial factors in the BOG re-liquefaction process. This review provides a comprehensive review of the recent advancements in the design and optimization of BOG re-liquefaction processes. It includes a detailed analysis and comparison of existing BOG re-liquefaction technologies, and specifically discusses two types of re-liquefaction processes: dynamic and steady-state. Furthermore, this review examines different perspectives and directions for improving these two re-liquefaction technologies. Finally, the challenges faced by the BOG re-liquefaction process for LNG carriers are presented, along with future directions for addressing these challenges.
Aeolian sediments play an important role in the global climatic system and occur in the atmosphere due to soil and bedrock erosion. Here, we applied three different methods: geochemical (XRF), manual ...and laser-based particle size analysis to an ombrotrophic peat profile in the Carpathian Mountains to determine changes in aeolian deposition and wind/storm activity over the last 7800 years. The results show the following changes in aeolian fluxes (dust and sand) over time: 7800–4150 cal. yr BP – generally low dust fluxes with a periodic intensification of sand fluxes; 4150–2300 cal. yr BP – intense deposition of both dust and sand; 2300–150 cal. yr BP – fluctuating dust and sand fluxes; the last 200 years – the highest amplitude of both sand and dust fluxes. This study found that patterns in aeolian fluxes were influenced by a combination of climate and human impact, but with anthropogenic drivers, such as disturbance by fire, becoming more important in recent times. We also found a good agreement with other studies of dust fluxes for the earlier part of this record, but an increasing divergence over the last 3500 years. In terms of a methodological approach, we suggest that the three approaches each have both advantages and disadvantages; though overall laser-based particle size dust and sand reconstruction appears to best capture the most complex changes in both aeolian deposition rates and sources.
•Reconstruction of past aeolian fluxes using ombrotrophic mountain bog•Four major shifts in aeolian fluxes in the past 7800 years•Identify the relationship between aeolian fluxes and their controlling factors•Aeolian fluxes were primarily influenced by climate and anthropogenic drivers.•Comparison with other records of aeolian estimates from central and northwest Europe
Until the beginning of the 20th century, bog burning culture was a common cultivation system for food production on otherwise non-arable bog peat soils. Burning and preliminary drainage of the peat ...impacted the soils nutrient supply, bog morphology and soils properties. To gain insights into the long-term effects of bog burning culture on the landscape and soils, a burned and unburned area within a rewetted bog complex were comparatively analysed. It was hypothesised that bog burning had a lasting effect on the soil chemistry, that the trenches created for drainage prior to burning are still detectable in the bog morphology, and that the altered soil chemistry exhibiting enhanced nutrient supply resulted in a change of vegetation patterns. To verify this, the soil chemistry was analysed regarding pH, carbon/nitrogen (C/N) ratio, and contents of plant available phosphate (PO₄3−) and potassium (K). The morphology was examined by means of aerial imagery and vegetation patterns were assessed in the field. It was shown that while PO₄3−- contents were similar, pH values and K contents of the burned area were elevated compared with the unburned area. Accordingly, they can be used as an indicator for bog burning culture, even a century after the end of the practice. As expected, C/N ratios were narrowed in the burned area, which however cannot exclusively be attributed to bog burning, since peat mineralisation in the previously drained bog soils caused narrowing C/N ratios as well. The trench structure for drainage was still visible in aerial images and vegetation patterns were similar in the burned and unburned areas. Overall, the aftermath of bog burning was still apparent in morphology and soil chemistry, however the effect was less severe than expected, as vegetation patterns and the overall restoration success were not impacted. This provides a reasonable expectation that bogs are resilient towards bog burning and the latter is no obstacle for successful restoration.
Bis zum Beginn des 20. Jahrhunderts war die Moorbrandkultur eine gängige Kultivierungspraxis zur landwirtschaftlichen Nutzbarmachung von Hochmoorböden. Die Nährstoffzufuhr durch das Moorbrennen sowie die vorherige Trockenlegung veränderten die Morphologie und Bodeneigenschaften. Um die Langzeitfolgen der Moorbrandkultur auf die Bodeneigenschaften und Vegetationsentwicklung zu untersuchen, wurden eine gebrannte und eine ungebrannte Fläche eines wiedervernässten Hochmoores vergleichend analysiert. Die Haupthypothese lautete, dass das Moorbrennen den Bodenchemismus nachhaltig beeinflusst hat. Eine zweite Hypothese war, dass die vor dem Moorbrennen zur Drainage angelegte Grüppenstruktur in der Hochmoor Morphologie noch zu erkennen ist. Außerdem wurde angenommen, dass die Nährstoffzufuhr durch das Moorbrennen zur Ausbildung eines veränderten Vegetationsmusters geführt hat. Um dies zu untersuchen wurde der Bodenchemismus hinsichtlich pH-Werten, Kohlenstoff/Stickstoff (C/N) Verhältnis sowie Gehalt an pflanzenverfügbarem Phosphat (PO₄3−) und Kalium (K) untersucht, die Oberflächenmorphologie wurden anhand von Luftbildmaterial untersucht und die Vegetationstypen wurden im Gelände bestimmt. Es konnte gezeigt werden, dass während sich die PO₄3− Gehalte ähnelten, die pH-Werte und Gehalte an pflanzenverfügbarem K in der gebrannten Fläche im Vergleich mit der ungebrannten Fläche erhöht waren und somit noch ein Jahrhundert nach Ende der Methode als ein Indikator für die frühere Moorbrandkultur dienen. Wie erwartet waren die C/N Verhältnisse in der gebrannten Fläche verengt, was jedoch nicht ausschließlich auf das Torfbrennen zurückgeführt werden kann, da die C/N Verhältnisse durch die vorangegangene Trockenlegung zusätzlich stark durch Mineralisierung beeinflusst wurden. Die charakteristische Grüppenstruktur für die Drainage war in den Luftbildern deutlich zu erkennen. Die Vegetationsstrukturen der gebrannten und ungebrannten Flächen ähnelten sich weitgehend. Die Nachwirkungen der Moorbrandkultur können also noch heute in der Oberflächenmorphologie und im Bodenchemismus nachgewiesen werden. Letztere fielen weniger stark aus als erwartet, da sie sich offenbar nicht maßgeblich auf die Vegetationsentwicklung auswirkten. Daher besteht Grund zur Annahme, dass Hochmoore resilient auf Moorbrandkultur reagieren und dass Moorbrandkultur kein Hindernis für den Erfolg einer Renaturierung darstellt.
Recent warming at high-latitudes has accelerated permafrost thaw in northern peatlands, and thaw can have profound effects on local hydrology and ecosystem carbon balance. To assess the impact of ...permafrost thaw on soil organic carbon (OC) dynamics, we measured soil hydrologic and thermal dynamics and soil OC stocks across a collapse-scar bog chronosequence in interior Alaska. We observed dramatic changes in the distribution of soil water associated with thawing of ice-rich frozen peat. The impoundment of warm water in collapse-scar bogs initiated talik formation and the lateral expansion of bogs over time. On average, Permafrost Plateaus stored 137 ± 37 kg C m⁻², whereas OC storage in Young Bogs and Old Bogs averaged 84 ± db 13 kg C m⁻². Based on our reconstructions, the accumulation of OC in near-surface bog peat continued for nearly 1,000 years following permafrost thaw, at which point accumulation rates slowed. Rapid decomposition of thawed forest peat reduced deep OC stocks by nearly half during the first 100 years following thaw. Using a simple mass-balance model, we show that accumulation rates at the bog surface were not sufficient to balance deep OC losses, resulting in a net loss of OC from the entire peat column. An uncertainty analysis also revealed that the magnitude and timing of soil OC loss from thawed forest peat depends substantially on variation in OC input rates to bog peat and variation in decay constants for shallow and deep OC stocks. These findings suggest that permafrost thaw and the subsequent release of OC from thawed peat will likely reduce the strength of northern permafrost-affected peatlands as a carbon dioxide sink, and consequently, will likely accelerate rates of atmospheric warming.
Peatlands Rotherham, Ian D.
2020, 20200428, 2020-04-28
eBook
This book provides an introduction to peatlands for the non-specialist student reader and for all those concerned about environmental protection, and is an essential guide to peatland history and ...heritage for scientists and enthusiasts.
Peat is formed when vegetation partially decays in a waterlogged environment and occurs extensively throughout both temperate and tropical regions. Interest in peatlands is currently high due to the degradation of global peatlands which is disrupting hydrology and contributing to greenhouse gas emissions. This book opens by explaining how peat is formed, its properties and worldwide distribution, and defines related terms such as mires, wetlands, bogs and marshes. There is discussion of the ecology and wildlife of peatlands as well as their ability to preserve pollen and organic remains as environmental archives. It also addresses the history, heritage and cultural exploitation of peat, extending back to pre-Roman times, and the degradation of peatlands over the centuries, particularly as a source of fuel but more recently for commercial horticulture. Other chapters discuss the ecosystem services delivered by peatlands, and how their destruction is contributing to biodiversity loss, flooding or drought, and climate change. Finally, the many current peatland restoration projects around the world are highlighted.
Overall the book provides a wide-ranging but concise overview of peatlands from both a natural and social science perspective, and will be invaluable for students of ecology, geography, environmental studies and history.
Peatland drainage is a large source of anthropogenic CO2 emissions. While conversion to agriculture is widely acknowledged to lead to “irrecoverable” carbon (C) losses, in contrast the C impacts of ...peatland forestry are poorly understood, especially in intensively managed plantations. Losses of C from peat oxidation are highly variable and can be compensated for by gains of C in trees, depending on the lifecycle of the timber and timescale considered. Here, we used ITRAX scanning to enable rapid detection of the Hekla 4 cryptotephra layer as a reliable chronological marker above which peat properties and C stocks could be compared between open and afforested blanket bog cores in the Flow Country of Northern Scotland. At one site, Bad a’ Cheò, we combine replicated core pair comparisons (n = 19) with timber extraction data to derive net ecosystem C balance over the lifetime of the plantation. Here the reduction in peat C carbon storage above Hekla 4 in afforested samples (67 t C ha−1) is only partially compensated by tree C sequestration (47 t C ha−1), leading to a net ecosystem C balance indicating a loss of 20 t C ha−1 over the 50 years since the plantation was established. At that site, ~65 % of tree C rapidly returned to the atmosphere, as it was primarily used for heat and power generation. Across the wider Flow country region, a simplified paired sampling method was adopted at eight further sites, finding a either a loss or negligible change in peat C storage above Hekla 4 in afforested samples with a mean loss of 86 t C ha−1 and median loss of 50 t C ha−1. This study suggests that potentially substantial C losses have been an unintended consequence of non-native conifer afforestation over deep blanket bogs.
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•In the 20th Century, large areas of deep peat were drained and afforested with conifers.•This study measured carbon stocks in afforested and undrained peat.•The Hekla 4 tephra deposit was used as a stratigraphic marker for assessing carbon accumulated.•C Total carbon in afforested areas was on average 20 t C ha−1 less than undrained peat after 60 years.•This stock-based study is of relevance to the ongoing policy debate on deep peat restoration.
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, PO43−, NH4+, 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 PO43−) and 0.5 kg N ha−1 (as NH4+) could be released from brash, over nine days.
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•Relative contributions of peat, needles and branches to water quality were assessed.•DOC, PO43−, NH4+, 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.
Mires or peatlands host unique biodiversity and provide many valuable ecosystem services. Mires often undergo different development phases during their evolution. Two mire phases that have clearly ...divergent hydrological regimes and characteristic biotas are minerotrophic fen and ombrotrophic bog. Open mires can be overgrown by trees and develop into peatland forests. Mire development trajectories are expected to be associated with three major factors—post‐glacial isostatic uplift, autogenic succession and climate‐induced changes. Understanding long‐term mire development is important for the conservation planning of these threatened habitats.
We use data from modern pollen samples to characterize differences between the pollen signal and to identify indicator pollen taxa for three mire development phases—open fens, forested fens and bogs. The modern reference samples are then used to support the interpretation of the sediment records in terms of mire development phases and related biodiversity changes in six mires within a 20 × 30 km area in western Saaremaa, Estonia. Palynological richness and phylogenetic diversity (PD) as well as Ellenberg indicator values are compared throughout the 10,000‐year history of the Saaremaa mires.
Pollen of herbaceous taxa discriminates between open fens, forested fens and bogs, and indicator pollen taxa can be associated with each mire phase. In general, the fen phases of the mires show higher richness and PD than the bog phases but there is considerable variation between the sites. The mire diversity peaks are often associated with transitional periods when high local community heterogeneity allows the coexistence of high numbers of taxa from different phylogenetic lineages.
Synthesis. When the initiation of mires in isostatic land uplift areas is closely related to water‐level changes and the position of the sites in relation to the sea, the development of mires and their biodiversity in the late Holocene is associated with local conditions but mediated by climate. The ongoing rapid climate change is likely to accelerate changes in existing mires, and while the transitional periods are characterized by high diversity, these periods are temporary, and the overall diversity of mires can be expected to decrease.
When the initiation of mires in isostatic land uplift areas is closely related to water‐level changes and the position of the sites in relation to the sea, the development of mires and their biodiversity in the late Holocene is associated with local conditions but mediated by climate. The ongoing rapid climate change is likely to accelerate changes in existing mires, and while the transitional periods are characterized by high diversity, these periods are temporary, and the overall diversity of mires can be expected to decrease.