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  • 1.
    Bastviken, David
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Kylin, Henrik
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Chlorine cycling and fates of 36Cl in terrestrial environments2013Report (Other academic)
    Abstract [en]

    Chlorine-36 (36Cl), a radioisotope of chlorine (Cl) with a half-life of 301,000 years, is present in some types of nuclear waste and is disposed in repositories for radioactive waste. As the release of 36Cl from such repositories to the near surface environment has to be taken into account it is of interest to predict possible fates of 36Cl under various conditions as a part of the safety assessments of repositories for radioactive waste. This report aims to summarize the state of the art knowledge on Cl cycling in terrestrial environments. The view on Cl cycling in terrestrial environments is changing due to recent research and it is clear that the chloride ion (Cl) is more reactive than previously believed. We group the major findings in three categories below according to the amount of data in support of the findings.

    From the result presented in this report it is evident that:

    • There is an ubiquitous and extensive natural chlorination of organic matter in terrestrial ecosystems.
    • The abundance of naturally formed chlorinated organic compounds (Clorg) frequently exceeds the abundance of Cl, particularly in soils. Thereby Clorg in many cases dominates the total Cl pool.
    • This has important implications for Cl transport. When reaching surface soils Cl will not be a suitable tracer of water and will instead enter other Cl pools (Clorg and biomass) that prolong residence times in the system.
    • Cl dominates import and export from terrestrial ecosystems while Clorg and biomass Cl can dominate the standing stock Cl within terrestrial ecosystems.
    • Both Cl and Clorg pools have to be considered separately in future monitoring programs addressing Cl cycling.

    Further, there are also indications (in need of confirmation by additional studies) that:

    • There is a rapid and large uptake of Cl by organisms and an accumulation in green plant parts. A surprisingly large proportion of total catchment Cl (up to 60%) can be found in the terrestrial biomass.
    • Emissions of total volatile organohalogens could be a significant export pathway of Cl from the systems.
    • Some of the Clorg may be very persistent and resist degradation better than average organic matter. This may lead to selective preservation of some Clorg (with associated low bioavailability).
    • There is a production of Clorg in tissues of e.g. plants and animals and Cl can accumulate as
    • chlorinated fatty acids in organisms.

    Most other nevertheless important aspects are largely unknown due to lack of data. Key unknowns include:

    • The development over time of major Cl pools and fluxes. As long as such data is lacking we cannot assess net changes over time.
    • How the precesses behind chlorination, dechlorination and transport patterns in terrestrial systems are regulated and affected by environmental factors.
    • The ecological roles of the chlorine cycling in general.
    • The ecological role of the microbial chlorination in particular.
    • The chlorine cycling in aquatic environments – including Cl and Clorg pools in sediment and water, are largely missing.

    Given the limited present information available, and particularly the lack of data with a temporal dimension and the lack of process understanding, predictive models are challenging. We also summarize currently available methods to study Cl in the environment.

  • 2.
    Johansson, Madelaine
    et al.
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Johansson, Anders
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Individuella basgruppsunderlag - ett verktyg för synliggörande av individuell kunslapsinhämtning och -bearbetning samt reflektion i basgruppsarbetet2012In: Utbildning - undervisning -utmaning - utveckling: En rapport från LiU:s utvecklingskonferens 10 mars 2011 / [ed] Elinor Edvardsson Stiwne, Linköping, 2012, p. 122-136Conference paper (Other academic)
    Abstract [sv]

    År 2005 introducerades individuella basgruppsunderlag (IBU) vid Miljövetarprogrammet som en del i det kontinuerliga utvecklingsarbete som pågår i lärargruppen. Motivet var primärt att synliggöra den enskilda studentens insatser och lärande men även att ge lärarna ett verktyg till säkrare bedömning av studentens aktiva deltagande i basgruppsarbetet. Då IBU är ett i PBLsammanhang nytt verktyg har vi sett ett behov av att utvärdera och dokumentera dess potential som ett stöd i studenternas lärande och som en förstärkning av möjligheterna att examinera den enskilde studentens insatser i basgruppen. Studien har visat att IBU:er har skapat möjligheter att stödja studenters lärande genom att synliggöra, såväl för studenten själv som handledaren, var i lärandeprocessen studenten befinner sig och erbjuder därigenom en möjlighet till stöd för studenternas metakognitiva kompetens, till stor del skapad genom dokumentationsprocessen. De intervjuade lärarna beskriver att IBU:er stärker möjligheten att bedöma studenternas förberedelser inför basgruppsmötet och därmed också examinera studentens aktiva deltagande i basgruppsarbetet .

  • 3.
    Gustavsson, Malin
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Karlsson, Susanne
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Oeberg, Gunilla
    University of British Columbia.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Valinia, Salar
    Swedish University of Agriculture Science.
    Thiry, Yves
    Andra, Chatenay Malabry, France .
    Bastviken, David
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Organic Matter Chlorination Rates in Different Boreal Soils: The Role of Soil Organic Matter Content2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 3, p. 1504-1510Article in journal (Refereed)
    Abstract [en]

    Transformation of chloride (Cl-) to organic chlorine (Cl-org) occurs naturally in soil but it is poorly understood how and why transformation rates vary among environments. There are still few measurements of chlorination rates in soils, even though formation of Cl-org has been known for two decades. In the present study, we compare organic matter (OM) chlorination rates, measured by Cl-36 tracer experiments, in soils from eleven different locations (coniferous forest soils, pasture soils and agricultural soils) and discuss how various environmental factors effect chlorination. Chlorination rates were highest in the forest soils and strong correlations were seen with environmental variables such as soil OM content and Cl- concentration. Data presented support the hypothesis that OM levels give the framework for the soil chlorine cycling and that chlorination in more organic soils over time leads to a larger Cl-org pool and in turn to a high internal supply of Cl- upon dechlorination. This provides unexpected indications that pore water Cl- levels may be controlled by supply from dechlorination processes and can explain why soil Cl- locally can be more closely related to soil OM content and the amount organically bound chlorine than to Cl- deposition.

  • 4.
    Bastviken, David
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Susanne
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    IRES, UBC, Canada.
    Temperature sensitivity indicates enzyme controlled chlorination of soil organic matter2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 10, p. 3569-3573Article in journal (Refereed)
    Abstract [en]

    Old assumptions that chloride is inert and that most chlorinated organic matter in soils is anthropogenic have been challenged by findings of naturally formed organochlorines. Such natural chlorination has been recognized for several decades, but there are still very few measurements of chlorination rates or estimates of the quantitative importance of terrestrial chlorine transformations. While much is known about the formation of specific compounds, bulk chlorination remains poorly understood in terms of mechanisms and effects of environmental factors. We quantified bulk chlorination rates in coniferous forest soil using 36Cl-chloride in tracer experiments at different temperatures and with and without molecular oxygen (O2). Chlorination was enhanced by the presence of O2 and had a temperature optimum at 20 °C. Minimum rates were found at high temperatures (50 °C) or under anoxic conditions. The results indicate (1) that most of the chlorination between 4 and 40 °C was biotic and driven by O2 dependent enzymes, and (2) that there is also slower background chlorination occurring under anoxic conditions at 20 °C and under oxic conditions at 50 °C. Hence, while oxic and biotic chlorination clearly dominated, chlorination by other processes including possible abiotic reactions was also detected.

  • 5.
    Laturnus, Frank
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Sandén, Per
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Wiencke, Christian
    AWI, Bremerhafen, Germany.
    Finding the scattered pieces of the mechanisms behind the formation of volatile halogen-containing C1- and C2-compounds in Antarctic macroalgae2008In: Reports on polar and marine research. 571, Alfred-Wegener Institut fur Polar- und Meeresforschung , 2008, p. 200-207Chapter in book (Other academic)
  • 6.
    Bastviken, David
    et al.
    Department of geology and geochemistry Stockholm University.
    Thomsen, Frida
    The Tema institute Linköpings universitet.
    Svensson, Teresia
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Karlsson, Susanne
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Shaw, George
    Division of agricultural and environmental sciences University of Nottingham.
    Matucha, Miroslav
    Institute of experimental botany Ac. Sci. Czech Rep.
    Öberg, Gunilla
    Institute for resources, environment and sustainability University of British Colombia.
    Chloride retention in forest soil by microbial uptake and by natural chlorination of organic matter2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 13, p. 3182-3192Article in journal (Refereed)
    Abstract [en]

    Inorganic chlorine (i.e. chloride, Clin) is generally considered inert in soil and is often used as a tracer of soil and ground water movements. However, recent studies indicate that substantial retention or release of Clin can occur in soil, but the rates and processes responsible under different environmental conditions are largely unknown. We performed 36Cl tracer experiments which indicated that short-term microbial uptake and release of Clin, in combination with more long-term natural formation of chlorinated organic matter (Clorg), caused Clin imbalances in coniferous forest soil. Extensive microbial uptake and release of Clin occurred over short time scales, and were probably associated with changes in environmental conditions. Up to 24% of the initially available Clin within pore water was retained by microbial uptake within a week in our experiments, but most of this Clin was released to the pore water again within a month, probably associated with decreasing microbial populations. The natural formation of Clorg resulted in a net immobilization of 4% of the initial pore water Clin over four months. If this rate is representative for the area where soil was collected, Clorg formation would correspond to a conversion of 25% of the yearly wet deposition of Clin. The study illustrates the potential of two Clin retaining processes in addition to those previously addressed elsewhere (e.g. uptake of chloride by vegetation). Hence, several processes operating at different time scales and with different regulation mechanisms can cause Clin imbalances in soil. Altogether, the results of the present study (1) provide evidence that Clin cannot be assumed to be inert in soil, (2) show that microbial exchange can regulate pore water Clin concentrations and (3) confirm the controversial idea of substantial natural chlorination of soil organic matter. © 2007 Elsevier Ltd. All rights reserved.

  • 7.
    Svensson, Teresia
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies.
    Bastviken, David
    Department of geology and geochemistry Stockholm, Sweden University.
    Öberg, Gunilla
    Institute for resources, environment and sustainability University of British Colombia, Canada.
    Chlorine transport in a small catchment in southeast Sweden during two years2007In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 82, no 2, p. 181-199Article in journal (Refereed)
    Abstract [en]

    Previous studies have revealed that chlorine participates in a complex biogeochemical cycle in soil, which suggests that the transport of chloride through catchments may also be influenced. The present study is based on field observations of organic carbon, chloride (Clin), and chlorinated organic carbon (Clorg) in precipitation, soil, and runoff over a 2-year period from a small, forested catchment in southeast Sweden. The study reveals that (1) the soil pool is dominated by Clorg, (2) the input via wet deposition and output of Clin via runoff is 30 times smaller than the total storage of chlorine (Clin + Clorg) in soil, and (3) the transport is dominated by Clin. The organic matter that entered the outlet of the catchment was more chlorinated in the autumn than during the rest of the year, and rain events taking place in low-flow periods had a greater influence on TOC, Clorg, and Clin than did rain events taking place in high-flow periods. The seasonal pattern in combination with the low-flow versus high-flow pattern and previous findings of increasing chlorine-to-carbon ratios with soil depth suggests that the chlorine-to-carbon ratio variation in the leached organic matter is due that water preferentially comes from deeper layers in low-flow conditions. This study provides well-founded estimates of Clorg and Clin storage and fluxes for the studied catchment; however, the processes underlying the observed seasonal Clorg variations and transportation processes need further study.

  • 8.
    Svensson, Teresia
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Laturnus, Frank
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Institute for Resources, Environment and Sustainability, Faculty of Graduate Studies, University of British Columbia, Aquatic Ecosystem Research Laboratory, Vancouver, BC, Canada.
    Chloroform in runoff water: a two-year study in a small catchment in southeast Sweden2007In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 82, no 2, p. 139-151Article in journal (Refereed)
    Abstract [en]

    Chloroform concentrations were observed and input and output fluxes estimated over a 2-yr period in a small coniferous catchment (0.22 km2) in southeast Sweden. Water discharge was measured daily, and runoff water was sampled bi-weekly for chloroform analysis. An approximate chloroform budget was calculated, which indicated that the annual output of 6 μg m−2 yr−1 was approximately six times higher than the input, inferring an internal source of chloroform in the catchment. To the best of our knowledge, neither flux estimates nor mass balances have previously been made for chloroform on a catchment scale, nor have data regarding natural runoff variation with time been gathered. Concentrations of chloroform in runoff were found to be generally high during wet periods, such as spring, but also peaked during summer rain events. The observed pattern suggests that chloroform is formed in surface soil layers and transported to the outlet under high-flow conditions and during dry-period rain events; it is lost through degradation or evaporation during drier periods due to longer soil water residence times. The data suggest that the variation among replicates increases with concentration; this emphasizes the need to know what the degree of on-site variation is, so one can collect a sufficient number of replicates to permit detection of spatial or temporal changes.

  • 9.
    Bastviken, David
    et al.
    Stockholm University.
    Sandén, Per
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ståhlberg, Carina
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Magounakis, Malin
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, Faculty of Arts and Sciences.
    Chloride retention and release in a boreal forest soil: effects of soil water residence time and nitrogen and chloride loads2006In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 40, no 9, p. 2977-2982Article in journal (Refereed)
    Abstract [en]

    The common assumption that chloride (Cl-) is conservative in soils and can be used as a groundwater tracer is currently being questioned, and an increasing number of studies indicate that Cl- can be retained in soils. We performed lysimeter experiments with soil from a coniferous forest in southeast Sweden to determine whether pore water residence time and nitrogen and Cl- loads affected Cl- retention. Over the first 42 days there was a net retention of Cl- with retention rates averaging 3.1 mg Cl- m-2 d-1 (68% of the added Cl- retained over 42 days). Thereafter, a net release of Cl- at similar rates was observed for the remaining experimental period (85 d). Longer soil water residence time and higher Cl- load gave higher initial retention and subsequent release rates than shorter residence time and lower Cl- load did. Nitrogen load did not affect Cl transformation rates. This study indicates that simultaneous retention and release of Cl- can occur in soils, and that rates may be considerable relative to the load. The retention of Cl- observed was probably due to chlorination of soil organic matter or ion exchange. The cause of the shift between net retention and net release is unclear, but we hypothesize that the presence of O2 or the presence of microbially available organic matter regulates Cl- retention and release rates.

  • 10.
    Öberg, Gunilla
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Retention of chloride in soil and cycling of organic matter-bound chlorine2005In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 19, no 11, p. 2123-2136Article in journal (Refereed)
    Abstract [en]

    Chloride (Cl-inorg) is generally considered to be a hydrologically and chemically inert substance. Past research suggests that Cl-inorg participates in a complex biogeochemical cycle involving the formation of organically bound chlorine (Cl-org). The present study examines whether Cl-org cycling is sufficiently extensive as to influence the geochemical cycling Of Cl-inorg- Undisturbed soil cores were collected in a coniferous forest soil in SE Sweden. The cores were stored in climate chambers for three months, irrigated with artificial rain, and the leachate was collected and analysed. The water balance of the lysimeters could be well described, and we found that 20-50% of the chlorine leached from the lysimeters was organically bound and that the amounts lost did not decrease with time. This strongly suggests that a substantial amount of Cl-inorg forms in topsoil, and that subsequent leaching to deeper layers causes a considerable withdrawal of Cl-inorg. The concentration of both organic carbon and Cl-inorg in the leachate was considerably higher than concentrations observed in the runoff in the actual catchment, suggesting that organic matter precipitates or is mineralized on its way through the soil. Copyright (c) 2005 John Wiley & Sons, Ltd.

  • 11.
    Öberg, Gunilla
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Holm, Mats
    Local Forest Administration, Östergötland, Sweden.
    Sandén, Per
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Parikka, Matti
    Department of Bioenergy, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    The role of organic matter bound chlorine in the chlorine cycle: a case study of the Stubbetorp catchment, Sweden2005In: Biogeochemistry, ISSN 0168-2563, Vol. 75, no 2, p. 241-269Article in journal (Refereed)
    Abstract [en]

    The objective of this study is to construct a balanced chlorine budget for a small forested catchment, focusing on the interaction between chloride (Clinorg) and organic-matter-bound chlorine (Clorg). Data from the actual catchment are combined with secondary data from other sites to elucidate more clearly which parts of the cycle are fairly well known and which are more or less unknown. The budget calculations show that the principal input and output fluxes of Cl in the catchment are inorganic but that the main pool is Clorg in the soil. In addition, the budget calculations suggest that a considerable portion of Clinorg in soil is transformed to Clorg and subsequently leached to deeper soil layers, that net mineralization of Clorg takes place in soil, preferably in deeper soil layers, and that degrading organic matter is a major source of Clinorg in runoff. The loss of Clorg through runoff is small to negligible in relation to other fluxes. It appears as if dry deposition of Clinorg is at risk of being underestimated if Clinorg is assumed to be conservative in soil. The pool of organic-matter-bound chlorine in soil is considerably larger than the annual flux of chloride through the system. The estimates suggest that the amount of Clorg in the upper 40 cm of the soil at the investigated site is approximately twice as large as the Clinorg. Furthermore, the amount of Clorg biomass is small in relation to the occurrence of Clorg in soil. Finally, the estimates indicate that the transport of volatile Clorg from the soil to the atmosphere may influence the chlorine cycle.

  • 12.
    Öberg, Gunilla
    et al.
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Holm, Mats
    Skogsvårdsstyrelsen Norrköpings distrikt.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Svensson, Teresia
    Linköping University, The Tema Institute.
    Parikka, Matti
    Institutionen för bioenergi Sveriges lantbruksuniversitet.
    Chlorine budget of a small catchment2004In: European Geosciences Union 1st Assembly,2004, 2004, p. 180-180Conference paper (Other academic)
  • 13.
    Benyamine, Michelle
    et al.
    Väågverket.
    Bäckström, Mattias
    Örebro universitet.
    Sandén, Per
    Linköping University, Department of Thematic Studies.
    Multi-objective environmental management in constructed wetlands2004In: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 90, no 1-3, p. 171-185Article in journal (Refereed)
    Abstract [en]

    We examined multi-objective environmental management as applied to pursuing concurrent goals of water treatment, biodiversity and promotion of recreation in constructed wetlands. A case study of a wetland established to treat landfill leachate, increase biodiversity, and promote recreation was evaluated. The study showed that attempts to combine pollution management with activities promoting biodiversity or recreation are problematic in constructed wetlands. This could be because the typical single-objective focus of scientific research leads to contradictions when planning, implementing and assessing the multi-objective use of wetlands. In the specific case of wetland filters for landfill leachate treatment, biodiversity, and recreation, there is a need for further research that meet practical needs to secure positive outcomes.

  • 14.
    Johansson, Emma
    et al.
    Linköping University, The Institute of Technology. Linköping University, Faculty of Arts and Sciences.
    Xin, ZB
    Hu, ZY
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Öberg, Gunilla
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Organic chlorine and chloride in submerged paddy soil: a case study in Anhui province, southeast China2004In: Soil use and management, ISSN 0266-0032, E-ISSN 1475-2743, Vol. 20, no 2, p. 144-149Article in journal (Refereed)
    Abstract [en]

    Efforts to understand the fate of organochlorine compounds in arable soil have concentrated on anthropogenic compounds, in spite of the fact that organochlorine compounds are both produced and mineralized in soil through natural processes. In order to understand the fate of chlorinated pesticides, it is necessary to take account of the natural chlorine cycle. The present study is a first attempt to illuminate the relationship between the natural chlorine cycle and agricultural practices. The concentration and storage of organic chlorine (Cl-org) and chloride (Cl-inorg) were determined in topsoil of a paddy field compared to an adjacent afforested hill at a sampling site in the Meicun area, Anhui Province, China. The concentration of Cl-org, as well as the chlorine-to-carbon ratio, was significantly lower in the paddy field samples than in the forest soil samples. A weak relationship between the concentration of Cl-org and the organic carbon content was observed in the paddy field, in contrast to the observations made in the adjacent forest soil as well as those made in previous studies, which have suggested a positive correlation between organic carbon content and Cl-org. The similarity between our results at the forest site and the previous studies, which have been carried out in temperate regions, suggests that it is the land use rather than the climate that makes the current paddy soil results different. Our results suggest that the contribution of Cl-org to the paddy soil from above-ground litter and from production within the soil are small or negligible compared with the contribution from pesticide application and wet and dry deposition.

  • 15.
    Benyamine, M.
    et al.
    Man-Technology-Environment Res. Ctr., Örebro University, Örebro, Sweden.
    Lidskog, R.
    Man-Technology-Environment Res. Ctr., Örebro University, Örebro, Sweden.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Theoretical disputes over forest nitrogen fertilization2004In: Journal of Environmental Planning and Management, ISSN 0964-0568, E-ISSN 1360-0559, Vol. 47, no 5, p. 651-665Article in journal (Refereed)
    Abstract [en]

    The theoretical disputes over forest nitrogen (N) fertilization constitute a difficulty for forest managers. In cases where scientists disagree it is hard for practitioners to make scientifically based decisions on what actions to take. The main objective in this study was to understand possible reasons for the scientific discussion associated with the question as to how fertilization for increased forest growth influences the forest ecosystem? Another objective was to clarify the divergent theoretical grounds within this scientific field. The study proceeded by selecting articles based on the criterion that they include field studies of fertilization for stem growth in the temperate region, and then analysing their theoretical content. Differences in theoretical grounds are among the reasons for the scientific disputes over the effects of N fertilization on forest ecosystems. © 2004 University of Newcastle upon Tyne.

  • 16. Rodstedth, M
    et al.
    Ståhlberg, Carina
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Sandén, Per
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Öberg, Gunilla
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Environmental Science.
    Chloride imbalances in soil lysimeters2003In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 52, no 2, p. 381-389Article in journal (Refereed)
    Abstract [en]

    The assumption that soil neither acts as a source or a sink of chloride is evaluated by incubating soil cores in lysimeters in a climate chamber under controlled conditions. Some of the lysimeters acted as a sink while others acted as a source of chloride. Considerable amounts of organic chlorine were lost by leaching. The loss by leaching of organic chlorine could only explain part of the discrepancy in the lysimeters where the soil acted as a sink and it could certainly not explain the cases where the soil acted as a source. The storage of organic chlorine was four times larger than the storage of chloride and comparably small changes in the organic chlorine storage will thus have a considerable influence on the chloride budget. However, the soil was too heterogeneous to determine whether a change in the storage had taken place or not. It is concluded that the observed chloride surplus and also, at least to some extent, the observed chloride deficit, most likely was caused by net-changes in the storage of organic chlorine in soil. An inverse correlation was found between the initial chloride content of the soil and the imbalance in the chloride budget. Dry deposition of chloride is generally assumed to equal the run-off minus the wet deposition. Extrapolation to the field situation suggests that the output of organic chlorine by soil leachate is at risk to cause an underestimation of the dry deposition by about 25%. (C) 2003 Elsevier Science Ltd. All rights reserved.

  • 17.
    Bratt, Anna
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Andersson, L.
    Sandén, Per
    Linköping University, The Tema Institute. Linköping University, Faculty of Arts and Sciences.
    Farmers questions and model answers on nitrogen leakage2003Article in journal (Refereed)
  • 18.
    Johansson, Emma
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, Department of Thematic Studies. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Organic chlorine in deciduous and coniferous forest soils in southern Sweden2003In: Soil science, ISSN 0038-075X, E-ISSN 1538-9243, Vol. 168, no 5, p. 347-355Article in journal (Refereed)
    Abstract [en]

    The concentration of organic chlorine (Clorg) was determined in soil samples collected in the O-horizon in forest soils in southern Sweden to describe differences among stand types and elucidate the influence of chloride (Clinorg), pH, and organic carbon. The samples were collected within the Swedish National Survey of Forest Soils and Vegetation, with moraine as the dominating soil type and with granite and gneiss as bedrock. The concentration of organic chlorine (Clorg) found in the deciduous forest soils was significantly lower than that in the coniferous forest soils. The Clorg increased with Clinorg, organic carbon content, and decreasing pH but was most strongly correlated to Clinorg. Crosswise comparisons among the variables showed that the influence of Clinorg overrode the influence of pH and organic carbon. We concluded that the major driving force in the formation of Clorg in soils is deposition of Clinorg and that the difference among deciduous and coniferous stands is due primarily to a higher input of Clinorg in the canopy of coniferous trees as a result of a larger wet and dry deposition in coniferous compared with deciduous forests. The concentration of Clorg decreased significantly from June to August. This follows the pattern of chloride deposition in the region and gives further evidence that Clinorg is a driving force in the formation of Clorg in soil. The results of the present study gives further evidence that the turnover of Clorg is closely related to the turnover of Clinorg and that it is necessary to include Clorg in the assessment of the biogeochemical cycling of chlorine in the environment.

  • 19.
    Bratt, Anna
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Graham, L. P.
    Sandén, Per
    Linköping University, The Tema Institute. Linköping University, Faculty of Arts and Sciences.
    Potential changes to nutrient leaching from adaptation of Swedish agricultural production to climate change2003Article in journal (Refereed)
  • 20.
    Johansson, Emma
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Sandén, Per
    Linköping University, Department of Thematic Studies. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Spatial patterns of organic chlorine and chloride in Swedish forest soil2003In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 52, no 2, p. 391-397Article in journal (Refereed)
    Abstract [en]

    The concentration of organic carbon, organic chlorine and chloride was determined in Swedish forest soil in the southern part of Sweden and the spatial distribution of the variables were studied. The concentration of organically bound chlorine was positively correlated to the organic carbon content, which is in line with previous studies. However, the spatial distribution patterns strongly indicate that some other variable adds structure to the spatial distribution of organic chlorine. The distribution patterns for chloride strongly resembled the distribution of organic chlorine. The spatial distribution of chloride in soil depends on the deposition pattern which in turn depends on prevailing wind-direction, amount of precipitation and the distance from the sea. This suggests that the occurrence of organic chlorine in soil is influenced by the deposition of chloride of some variable that co-varies with chloride. Two clearly confined strata were found in the area: the concentrations of organic chlorine and chloride in the western area were significantly higher than in the eastern area. No such difference among the two areas was seen regarding the carbon content.

  • 21.
    Johansson, Emma
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ebenå, Gustav
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Sandén, Per
    Linköping University, Department of Thematic Studies, Environmental Science. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, Department of Thematic Studies, Environmental Science. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Organic and chlorine in Swedish spruce forest soil: Influence of nitrogen2001In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 101, no 3-4, p. 1-13Article in journal (Refereed)
    Abstract [en]

    Concentrations of organic and inorganic chlorine were estimated in samples collected in forest soils in the southern part of Sweden, and changes were observed after the addition of nitrogen in incubated samples. All of the investigated samples contained both inorganic and organic chlorine, and the concentration of organic chlorine was 2-4 times larger than that of inorganic chlorine. The results suggest that the amount of organic chlorine in mature spruce forest soils with a moderate chloride deposition in the temperate region is larger than the amount of inorganic chlorine. The results of the nitrogen incubation indicate that addition of ammonium nitrate causes a net decrease in the concentration of organic chlorine and a net increase in chloride concentration. The observed change appears to mainly be a result of a dechlorination of the organic matter present in the water leachable fraction. © 2001 Elsevier Science B.V.

  • 22.
    Sandén, Per
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Dynamics of Metal Concentration and Mass Transport in an Old Mining Area1988Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Several different approaches were used to analyse the metal pollution in the mining area at Bersbo. Using extensive water flow and metal concentration data, the mean annual transport of copper, cadmium and zinc at a weir downstream from one of the tailings deposits was estimated to be 330, 5.9 and 1700 kg/yr, respectively. Furthermore, it was found that differences in water balance between the deposit itself and the surrounding area could explain a considerable fraction of the temporal variation in metal concentrations in the draining creek. Assuming that sulphate concentrations could be used to estimate the dilution in this creek, it was also shown that there was a pH-dependent sorption of metals to the bottom sediments of the creek.

    The use of the PULSE model for the simulation of water flow made it feasible to describe and compare the dynamics of metal transport at different sites in the study area. While the weathering rate was an important factor for the dynamics close to the deposit, the dynamics further downstream were almost exclusively determined by the water flow and, thus far unidentified, mechanisms maintaining fairly constant metalconcentrations in the stream water. Furthermore, the estimates of metal transport at different sites showed that the transport was considerably larger further downstream than close to the deposit.

    At a general level, the application of the PULSE model to the Bersho problem illustrated the power of this type of model to contribute to redefinitions of pollution problems. The concept of a single point-source was replaced by a multi-source concept, and the crucial role of the factors maintaining a fairly constant metal concentration further downstream was demonstrated.

  • 23.
    Johansson, Emma
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Zhang, Björn Xin
    Institute of Soil Science, Academica Sinica, Nanjing, P.R. China.
    Hu, Zhengyi
    Institute of Soil Science, Academica Sinica, Nanjing, P.R. China.
    Sandén, Per
    Linköping University, The Tema Institute. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Spatial Patterns of Organic Chlorine and Chloride in Farmland and Forest Soil in the Meicun Area, South East ChinaManuscript (preprint) (Other academic)
    Abstract [en]

    The concentration and storage of organic chlorine and chloride were determined in topsoil in a coniferous forest soil and a paddy soil at a sampling site in the Meicun area, Anhui Province, P.R. China. Also, the spatial distribution of the two forms of chlorine was determined and linear interpolation was used to construct contour maps of the concentrations. Soil samples were collected at 55 of the nodes in a grid with approximately 120 m between the nodes. In all, 27 samples from the forest and 28 from the paddy soil were collected and analyzed with respect to chloride, organic chlorine, organic carbon, pH, total nitrogen,ammonium and nitrate.

    The concentration of organic chlorine was at both sites significantly lower than that of chloride. Furthermore, the concentration of organic chlorine was significantly lower in the paddy as compared to the forest soil whereas the concentration of chloride did not differ significantly.

    The analysis of spatial variability suggested that no spatial correlation between the nearest sampling points and those further away were at hand. The contour maps indicated that the distribution pattern of organic chlorine in the forest soil was similar to the distribution of organic carbon, the highest and lowest concentrations of each occurring at about the same locations in the grid. The distribution of chloride showed a different pattern where the highest concentrations coincided with the most elevated parts of the hill. No clear patterns were observed for the three variables in the paddy field.

1 - 23 of 23
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