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Chauhan A, Patzner MS, Bhattacharyya A, Borch T, Fischer S, Obst M, ThomasArrigo LK, Kretzschmar R, Mansor M, Bryce C, Kappler A, Joshi P. Interactions between iron and carbon in permafrost thaw ponds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174321. [PMID: 38942322 DOI: 10.1016/j.scitotenv.2024.174321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/24/2024] [Accepted: 06/24/2024] [Indexed: 06/30/2024]
Abstract
Thawing permafrost forms "thaw ponds" that accumulate and transport organic carbon (OC), redox-active iron (Fe), and other elements. Although Fe has been shown to act as a control on the microbial degradation of OC in permafrost soils, the role of iron in carbon cycling in thaw ponds remains poorly understood. Here, we investigated Fe-OC interactions in thaw ponds in partially and fully thawed soils ("bog" and "fen" thaw ponds, respectively) in a permafrost peatland complex in Abisko, Sweden, using size separation (large particulate fraction (LPF), small particulate fraction (SPF), and dissolved fraction (DF)), acid extractions, scanning electron microscopy (SEM), Fe K-edge X-ray absorption spectroscopy (XAS), and Fourier Transform Infrared (FTIR) spectroscopy. The bulk total Fe (total suspended Fe) in the bogs ranged from 135 mg/L (mean = 13 mg/L) whereas the fens exhibited higher total Fe (1.5 to 212 mg/L, mean = 30 mg/L). The concentration of bulk total OC (TOC) in the bog thaw ponds ranged from 50 to 352 mg/L (mean = 170 mg/L), higher than the TOC concentration in the fen thaw ponds (8.5 to 268 mg/L, mean = 17 mg/L). The concentration of 1 M HCl-extractable Fe in the bog ponds was slightly lower than that in the fens (93 ± 1.2 and 137 ± 3.5 mg/L Fe, respectively) with Fe predominantly (>75 %) in the DF in both thaw stages. Fe K-edge XAS analysis showed that while Fe(II) was the predominant species in LPF, Fe(III) was more abundant in the DF, indicating that the stage of thawing and particle size may control Fe redox state. Furthermore, Fe(II) and Fe(III) were partially complexed with natural organic matter (NOM, 8 to 80 %) in both thaw ponds. Results of our work suggest that Fe and OC released during permafrost thaw into thaw ponds (re-)associate, potentially protecting OC from microbial decomposition while also stabilizing the redox state of Fe.
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Affiliation(s)
- Ankita Chauhan
- Geomicrobiology, Department of Geosciences, University of Tübingen, Germany; Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infection, Tübingen, Germany
| | - Monique S Patzner
- Geomicrobiology, Department of Geosciences, University of Tübingen, Germany
| | | | - Thomas Borch
- Department of Soil & Crop Sciences and Department of Chemistry, Colorado State University, United States
| | - Stefan Fischer
- Tübingen Structural Microscopy Core Facility, University of Tübingen, Germany
| | - Martin Obst
- Experimental Biogeochemistry, BayCEER, University of Bayreuth, Germany
| | - Laurel K ThomasArrigo
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, Switzerland; Environmental Chemistry Group, Institute of Chemistry, University of Neuchâtel, Switzerland
| | - Ruben Kretzschmar
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zürich, Switzerland
| | - Muammar Mansor
- Geomicrobiology, Department of Geosciences, University of Tübingen, Germany
| | - Casey Bryce
- School of Earth Sciences, University of Bristol, UK
| | - Andreas Kappler
- Geomicrobiology, Department of Geosciences, University of Tübingen, Germany; Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infection, Tübingen, Germany
| | - Prachi Joshi
- Geomicrobiology, Department of Geosciences, University of Tübingen, Germany.
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Xu H, Wang C, Ge M, Sardans J, Peñuelas J, Tong C, Wang W. Salinity increases under sea level rise strengthens the chemical protection of SOC in subtropical tidal marshes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176512. [PMID: 39368506 DOI: 10.1016/j.scitotenv.2024.176512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 09/13/2024] [Accepted: 09/23/2024] [Indexed: 10/07/2024]
Abstract
The rise in sea levels due to global warming could significantly impact the soil organic carbon (SOC) pool in coastal tidal marshes by altering soil salinity and flooding conditions. However, the effects of these factors on SOC protection in coastal tidal marshes are not fully understood. In this study, we employed a space-for-time approach to investigate the variations in soil active carbon components and mineral-associated organic carbon under different salinity gradients (freshwater and brackish) and flooding frequencies (high and low tidal flats). The soil organic carbon (SOC) and easily oxidizable organic carbon (EOC) contents at the low-flooding frequency sites were higher than those at the high-flooding frequency sites. The dissolved organic carbon (DOC) content was higher at the high-salinity sites compared to the low-salinity sites, while the soil microbial biomass carbon (MBC) content was higher at the low-salinity sites than at the high-salinity sites. The EOC/SOC and DOC/SOC ratios were greater at the high-salinity sites than at the low-salinity sites, whereas the MBC/SOC ratios were higher at the low-salinity sites than at the high-salinity sites. Iron (Fe) and aluminum (Al) mineral-associated organic carbon [Fe(Al)-OC] and calcium-associated organic carbon (Ca-OC) contents were higher at the high-salinity sites compared to the low-salinity sites, and at the low-flooding frequency sites compared to the high-flooding frequency sites. Meanwhile, Fe(Al)-OC was the dominant fraction among mineral-associated organic carbon at all sites. The dominant phyla of bacterial community included Proteobacteria (49.31 %-66.36 %), Firmicutes (2.67 %-28.44 %), Chloroflexi (3.81 %-9.54 %), and Acidobacteria (4.28 %-7.02 %). In addition, Desulfobacca, a sulfate-reducing bacterium, promoted the formation of mineral-associated organic carbon. Random forest analysis showed that SOC and DOC were key factors in promoting mineral-associated organic carbon formation. Partial least squares path modeling (PLS-PM) indicated that sea level rise affects DOC content by altering soil physicochemical properties, promoting the formation of mineral-associated organic carbon. In summary, while soil organic carbon activity increases, the chemical association of minerals with organic carbon is becoming increasingly crucial for the protection of organic carbon under rising salinity conditions driven by sea level rise.
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Affiliation(s)
- Hongda Xu
- Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China
| | - Chun Wang
- Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China.
| | - Maoquan Ge
- Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China
| | - Jordi Sardans
- CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès 08193, Catalonia, Spain.
| | - Josep Peñuelas
- CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès 08193, Catalonia, Spain
| | - Chuan Tong
- Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China
| | - Weiqi Wang
- Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China
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Pascual D, Åkerman J, Becher M, Callaghan TV, Christensen TR, Dorrepaal E, Emanuelsson U, Giesler R, Hammarlund D, Hanna E, Hofgaard A, Jin H, Johansson C, Jonasson C, Klaminder J, Karlsson J, Lundin E, Michelsen A, Olefeldt D, Persson A, Phoenix GK, Rączkowska Z, Rinnan R, Ström L, Tang J, Varner RK, Wookey P, Johansson M. The missing pieces for better future predictions in subarctic ecosystems: A Torneträsk case study. AMBIO 2021; 50:375-392. [PMID: 32920769 PMCID: PMC7782653 DOI: 10.1007/s13280-020-01381-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/08/2020] [Accepted: 08/08/2020] [Indexed: 05/06/2023]
Abstract
Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.
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Affiliation(s)
- Didac Pascual
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | - Jonas Åkerman
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | - Marina Becher
- Geological Survey of Sweden, Box 670, 751 28 Uppsala, Sweden
| | - Terry V. Callaghan
- Alfred Denny Building, University of Sheffield, Western Bank, Sheffield, S10 2TN UK
- Department of Botany, National Research Tomsk State University, 36 Lenin Ave., Tomsk, Russia 634050
| | - Torben R. Christensen
- Department of Bioscience, Faculty of Technical Sciences, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Ellen Dorrepaal
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 90187 Umeå, Sweden
| | - Urban Emanuelsson
- Swedish Biodiversity Centre, Swedish University of Agricultural Sciences, Mobergavägen 19, 373 54 Senoren, Sweden
| | - Reiner Giesler
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 90187 Umeå, Sweden
| | - Dan Hammarlund
- Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | - Edward Hanna
- School of Geography, Think Tank, Ruston Way, Lincoln, LN6 7FL UK
| | - Annika Hofgaard
- Norwegian Institute for Nature Research, Torgarden, P.O. Box 5685, 7485 Trondheim, Norway
| | - Hongxiao Jin
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Cecilia Johansson
- Department of Earth Sciences, Uppsala University, Villavägen 16, 752 36 Uppsala, Sweden
| | - Christer Jonasson
- Department of Social and Economic Geography, Uppsala University, Box 513, 751 20 Uppsala, Sweden
| | - Jonatan Klaminder
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 90187 Umeå, Sweden
| | - Jan Karlsson
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, 90187 Umeå, Sweden
| | - Erik Lundin
- Swedish Polar Research Secretariat, Luleå tekniska universitet, 971 87 Luleå, Sweden
| | - Anders Michelsen
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark
| | - David Olefeldt
- Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, T6G 2H1 Canada
| | - Andreas Persson
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | - Gareth K. Phoenix
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN UK
| | - Zofia Rączkowska
- Department of Geoenvironmental Research, Institute of Geography and Spatial Organisation PAS, Św. Jana 22, 31-018 Kraków, Poland
| | - Riikka Rinnan
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Lena Ström
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
| | - Jing Tang
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
- Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Ruth K. Varner
- Department of Earth Sciences, University of New Hampshire, Morse Hall Rm 455, 8 College Rd., Durham, NH 03824 USA
| | - Philip Wookey
- Biology and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA Scotland UK
| | - Margareta Johansson
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
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Payandi-Rolland D, Shirokova LS, Tesfa M, Bénézeth P, Lim AG, Kuzmina D, Karlsson J, Giesler R, Pokrovsky OS. Dissolved organic matter biodegradation along a hydrological continuum in permafrost peatlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:141463. [PMID: 32827830 DOI: 10.1016/j.scitotenv.2020.141463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/30/2020] [Accepted: 08/01/2020] [Indexed: 06/11/2023]
Abstract
Arctic regions contain large amounts of organic carbon (OC) trapped in soil and wetland permafrost. With climate warming, part of this OC is released to aquatic systems and degraded by microorganisms, thus resulting in positive feedback due to carbon (C) emission. In wetland areas, water bodies are spatially heterogenic and separated by landscape position and water residence time. This represents a hydrological continuum, from depressions, smaller water bodies and lakes to the receiving streams and rivers. Yet, the effect of this heterogeneity on the OC release from the soil and its processing in waters is largely unknown and not accounted for in C cycle models of Arctic regions. Here we investigated the dissolved OC (DOC) biodegradation of aquatic systems along a hydrological continuum located in two discontinuous permafrost sites: in western Siberia and northern Sweden. The biodegradable dissolved OC (BDOC15; % DOC lost relative to the initial DOC concentration after 15 days incubation at 20 °C) ranged from 0 to 20% for small water bodies located at the beginning of the continuum (soil solutions, small ponds, fen and lakes) and from 10 to 20% for streams and rivers. While the BDOC15 increased, the removal rate of DOC decreased along the hydrological continuum. The potential maximum CO2 production from DOC biodegradation was estimated to account for only a small part of in-situ CO2 emissions measured in peatland aquatic systems of northern Sweden and western Siberia. This suggests that other sources, such as sediment respiration and soil input, largely contribute to CO2 emissions from small surface waters of permafrost peatlands. Our results highlight the need to account for large heterogeneity of dissolved OC concentration and biodegradability in order to quantify C cycling in arctic water bodies susceptible to permafrost thaw.
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Affiliation(s)
- D Payandi-Rolland
- Geoscience and Environment Toulouse, GET-CNRS-IRD-OMP, University of Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France.
| | - L S Shirokova
- Geoscience and Environment Toulouse, GET-CNRS-IRD-OMP, University of Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France; N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia
| | - M Tesfa
- Geoscience and Environment Toulouse, GET-CNRS-IRD-OMP, University of Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France
| | - P Bénézeth
- Geoscience and Environment Toulouse, GET-CNRS-IRD-OMP, University of Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France
| | - A G Lim
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr., Tomsk, Russia
| | - D Kuzmina
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr., Tomsk, Russia
| | - J Karlsson
- Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science, Umeå University, SE-981 07 Abisko, Sweden
| | - R Giesler
- Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science, Umeå University, SE-981 07 Abisko, Sweden
| | - O S Pokrovsky
- Geoscience and Environment Toulouse, GET-CNRS-IRD-OMP, University of Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France; N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia; BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr., Tomsk, Russia
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Lauerwald R, Regnier P, Guenet B, Friedlingstein P, Ciais P. How Simulations of the Land Carbon Sink Are Biased by Ignoring Fluvial Carbon Transfers: A Case Study for the Amazon Basin. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.oneear.2020.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Shi S, Yang M, Hou Y, Peng C, Wu H, Zhu Q, Liang Q, Xie J, Wang M. Simulation of dissolved organic carbon concentrations and fluxes in Chinese monsoon forest ecosystems using a modified TRIPLEX-DOC model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134054. [PMID: 31476510 DOI: 10.1016/j.scitotenv.2019.134054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Dissolved organic carbon (DOC) plays an important role in global and regional carbon cycles. However, the quantification of DOC in forest ecosystems remains uncertain. Here, the processed-based biogeochemical model TRIPLEX-DOC was modified by optimizing the function of soil organic carbon distribution with increasing depths, as well as DOC sorption-desorption efficiency. The model was validated by field measurements of DOC concentration and flux at five forest sites and Beijiang River basin in monsoon regions of China. Model validation indicated that seasonal patterns of DOC concentration across climatic zones were different, and these differences were captured by our model. Importantly, the modified model performed better than the original model. Indeed, model efficiency of the modified model increased from -0.78 to 0.19 for O horizon predictions, and from -0.46 to 0.42 for the mineral soils predictions. Likewise, DOC fluxes were better simulated by the modified model. At the site scale, the simulated DOC fluxes were strongly correlated with the observed values (R2 = 0.97, EF = 0.91). At the regional scale, the DOC flux predicted in the Beijiang River basin was 16.44 kg C/ha, which was close to the observed value of 17 kg C/ha. Using sensitivity analysis, we showed that temperature, precipitation and temperature sensitivity of DOC decomposition (Q10) were the most sensitive parameters when predicting DOC concentrations and fluxes in forest soils. We also found that both the percentage of DOC flux to forest net ecosystem productivity, and the retention of DOC by mineral soil were highly correlated with the amount of precipitation. Overall, our model validations indicated that the modified TRIPLEX-DOC model is a useful tool for simulating the dynamics of DOC concentrations and fluxes in forest ecosystems. We highlight that more accurate estimates of parameter Q10 in deep mineral soils can reduce model uncertainty, when simulating DOC concentrations and fluxes in forest soils.
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Affiliation(s)
- Shengwei Shi
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; Beijing University of Agriculture, Beijing 102206, China; Center for Ecological Forecasting and Global Change, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Mingxia Yang
- Center for Ecological Forecasting and Global Change, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yue Hou
- Center for Ecological Forecasting and Global Change, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Changhui Peng
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; Center of CEF/ESCER, Department of Biological Science, University of Quebec at Montreal, Montreal H3C 3P8, Canada.
| | - Haibin Wu
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiuan Zhu
- College of Hydrology and Water resources, Hohai University, Nanjing 210098, China
| | - Qiong Liang
- Beijing University of Agriculture, Beijing 102206, China
| | - Junfei Xie
- Beijing Institute of Landscape Architecture, Beijing 100102, China
| | - Meng Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun 130024, China
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Microtopography Controls of Carbon and Related Elements Distribution in the West Siberian Frozen Bogs. GEOSCIENCES 2019. [DOI: 10.3390/geosciences9070291] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The West Siberian Plain stands out among other boreal plains by phenomenal bogging, which has both global and regional significance. The polygonal bogs, frozen raised-mound bogs, and ombrotrophic ridge-hollow raised bogs are the most extensive bog types in the study area. These bogs commonly show highly diverse surface patterns consisting of mounds, polygons, ridges, hollows, and fens that correspond to the microtopes. Here we investigated how the microtopographic features of the landscape affect the thermal and hydrologic conditions of the soil as well as the nutrient availability and consequently, the dynamics of carbon and related elements. The effect of the surface heterogeneity on the temperature regimes and depths of permafrost is most significant. All of these factors together are reflected, through the feedback system, by a number of hydrochemical parameters of bog waters, such as dissolved organic and inorganic carbon (DOC, DIC), specific conductivity (Cond), SO42–, Cl–, P, Sr, Al, Ti, Cu, V, B, Cs, Cd, Rb, As, U, and rare earth elements (REEs). Among the studied parameters, DOC, SO42, Al, V, and Mn differ most significantly between the convex and concave microforms. The DOC content in bog water is significantly affected by the water residence time, which is significantly longer in soils of mound/polygons than fens. Plants biomass is higher on the mounds which also have some effect that, due to leaching, should lead to more carbon entering into the water of the mounds. It is also shown that atmospheric-dust particles have a noticeable effect on the hydrochemical parameters of bog waters, especially on mounds. The ongoing climate warming will lead to an increase in the fens area and to a decrease in the content of DOC and many elements in bog waters.
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Zhang R, Jiang L, Zhong M, Han D, Zheng R, Fu Q, Zhou Y, Ma J. Applicability of Soil Concentration for VOC-Contaminated Site Assessments Explored Using Field Data from the Beijing-Tianjin-Hebei Urban Agglomeration. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:789-797. [PMID: 30532954 DOI: 10.1021/acs.est.8b03241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A total of 128 available soil-soil gas data pairs of benzene were collected from 5 contaminated sites in the Beijing-Tianjin-Hebei urban agglomeration. Soil gas concentrations predicted by the linear model and the dual equilibrium desorption (DED) model were compared with measured values. Although the immersion of soil samples in methanol during sampling and preservation was specified to minimize volatilization losses and biodegradation, the study still found that many points with high soil gas concentrations correspond to unreasonably low soil concentrations. Further analysis revealed that the soil matrices of these points are basically composed of sandy and silty soils, given that soil gas collected may migrate from more contaminated soils nearby due to the large porosity and soil benzene escapes more easily during sampling in the coarser soil particles. Therefore, for sandy and silty soil, collecting soil gas would be more reasonable for screening the vapor intrusion (VI) pathway. For clay, the combination of bulk soil concentration and the DED model will be more convenient. Defaulting f as 1, as recommended by previous studies in the DED, would not be suitable for all cases, and this value needs to be further explored to revise the DED model for future applications.
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Affiliation(s)
- Ruihuan Zhang
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Lin Jiang
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Maosheng Zhong
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Dan Han
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Rui Zheng
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Quankai Fu
- National Engineering Research Centre of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites , Beijing Municipal Research Institute of Environmental Protection , Beijing 100037 , China
| | - Youya Zhou
- State Key Laboratory of Environmental Criteria and Risk Assessment , China Research Academy of Environmental Sciences , Beijing 100012 , China
| | - Jie Ma
- State Key Laboratory of Heavy Oil Processing, Beijing Key Lab of Oil & Gas Pollution Control , China University of Petroleum- Beijing , Beijing 102249 , China
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