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  • 1251. Stephens, Lucas
    et al.
    Fuller, Dorian
    Boivin, Nicole
    Rick, Torben
    Gauthier, Nicolas
    Kay, Andrea
    Marwick, Ben
    Geralda, Chelsey
    Armstrong, Denise
    Barton, C. Michael
    Denham, Tim
    Douglass, Kristina
    Driver, Jonathan
    Janz, Lisa
    Roberts, Patrick
    Rogers, J. Daniel
    Thakar, Heather
    Altaweel, Mark
    Johnson, Amber L.
    Sampietro Vattuone, Maria Marta
    Aldenderfer, Mark
    Archila, Sonia
    Artioli, Gilberto
    Bale, Martin T.
    Beach, Timothy
    Borrell, Ferran
    Braje, Todd
    Buckland, Philip I.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Jiménez Cano, Nayeli Guadalupe
    Capriles, José M.
    Diez Castillo, Agustín
    \c Cilingiro\u glu, \c Ciler
    Negus Cleary, Michelle
    Conolly, James
    Coutros, Peter R.
    Covey, R. Alan
    Cremaschi, Mauro
    Crowther, Alison
    Der, Lindsay
    di Lernia, Savino
    Doershuk, John F.
    Doolittle, William E.
    Edwards, Kevin J.
    Erlandson, Jon M.
    Evans, Damian
    Fairbairn, Andrew
    Faulkner, Patrick
    Feinman, Gary
    Fernandes, Ricardo
    Fitzpatrick, Scott M.
    Fyfe, Ralph
    Garcea, Elena
    Goldstein, Steve
    Goodman, Reed Charles
    Dalpoim Guedes, Jade
    Herrmann, Jason
    Hiscock, Peter
    Hommel, Peter
    Horsburgh, K. Ann
    Hritz, Carrie
    Ives, John W.
    Junno, Aripekka
    Kahn, Jennifer G.
    Kaufman, Brett
    Kearns, Catherine
    Kidder, Tristram R.
    Lanoë, Fran\c cois
    Lawrence, Dan
    Lee, Gyoung-Ah
    Levin, Maureece J.
    Lindskoug, Henrik B.
    López-Sáez, José Antonio
    Macrae, Scott
    Marchant, Rob
    Marston, John M.
    McClure, Sarah
    McCoy, Mark D.
    Miller, Alicia Ventresca
    Morrison, Michael
    Motuzaite Matuzeviciute, Giedre
    Müller, Johannes
    Nayak, Ayushi
    Noerwidi, Sofwan
    Peres, Tanya M.
    Peterson, Christian E.
    Proctor, Lucas
    Randall, Asa R.
    Renette, Steve
    Robbins Schug, Gwen
    Ryzewski, Krysta
    Saini, Rakesh
    Scheinsohn, Vivian
    Schmidt, Peter
    Sebillaud, Pauline
    Seitsonen, Oula
    Simpson, Ian A.
    So\ltysiak, Arkadiusz
    Speakman, Robert J.
    Spengler, Robert N.
    Steffen, Martina L.
    Storozum, Michael J.
    Strickland, Keir M.
    Thompson, Jessica
    Thurston, T. L.
    Ulm, Sean
    Ustunkaya, M. Cemre
    Welker, Martin H.
    West, Catherine
    Williams, Patrick Ryan
    Wright, David K.
    Wright, Nathan
    Zahir, Muhammad
    Zerboni, Andrea
    Beaudoin, Ella
    Munevar Garcia, Santiago
    Powell, Jeremy
    Thornton, Alexa
    Kaplan, Jed O.
    Gaillard, Marie-José
    Klein Goldewijk, Kees
    Ellis, Erle
    Archaeological assessment reveals Earth’s early transformation through land use2019Inngår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 365, nr 6456, s. 897-902Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Humans began to leave lasting impacts on Earth’s surface starting 10,000 to 8000 years ago. Through a synthetic collaboration with archaeologists around the globe, Stephens et al. compiled a comprehensive picture of the trajectory of human land use worldwide during the Holocene (see the Perspective by Roberts). Hunter-gatherers, farmers, and pastoralists transformed the face of Earth earlier and to a greater extent than has been widely appreciated, a transformation that was essentially global by 3000 years before the present.Science, this issue p. 897; see also p. 865Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 years before the present (yr B.P.) to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers, and pastoralists by 3000 years ago, considerably earlier than the dates in the land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by more than 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked for 2000 yr B.P. and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth’s transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon.

  • 1252. Stone, Jeffery R.
    et al.
    Westover, Karlyn S.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Cohen, Andrew S.
    Late Pleistocene paleohydrography and diatom paleoecology of the central basin of Lake Malawi, Africa2011Inngår i: Palaeogeography, Palaeoclimatology, Palaeoecology, ISSN 0031-0182, E-ISSN 1872-616X, Vol. 303, nr 1-4, s. 51-70Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Analysis of sedimentary diatom assemblages (10 to 144 ka) form the basis for a detailed reconstruction of the paleohydrography and diatom paleoecology of Lake Malawi. Lake-level fluctuations on the order of hundreds of meters were inferred from dramatic changes in the fossil and sedimentary archives. Many of the fossil diatom assemblages we observed have no analog in modern Lake Malawi. Cyclotelloid diatom species are a major component of fossil assemblages prior to 35 ka, but are not found in significant abundances in the modern diatom communities in Lake Malawi. Salinity- and alkalinity-tolerant plankton has not been reported in the modern lake system, but frequently dominant fossil diatom assemblages prior to 85 ka. Large stephanodiscoid species that often dominate the plankton today are rarely present in the fossil record prior to 31 ka. Similarly, prior to 31 ka, common central-basin aulacoseiroid species are replaced by species found in the shallow, well-mixed southern basin. Surprisingly, tychoplankton and periphyton were not common throughout prolonged lowstands, but tended to increase in relative abundance during periods of inferred deeper-lake environments. A high-resolution lake level reconstruction was generated by a principle component analysis of fossil diatom and wet-sieved fossil and mineralogical residue records. Prior to 70 ka, fossil assemblages suggest that the central basin was periodically a much shallower, more saline and/or alkaline, well-mixed environment. The most significant reconstructed lowstands are 600 m below the modern lake level and span thousands of years. These conditions contrast starkly with the deep, dilute, dysaerobic environments of the modern central basin. After 70 ka, our reconstruction indicates sustained deeper-water environments were common, marked by a few brief, but significant, lowstands. High amplitude lake-level fluctuations appear related to changes in insolation. Seismic reflection data and additional sediment cores recovered from the northern basin of Lake Malawi provide evidence that supports our reconstruction.

  • 1253.
    Strandberg, Bo
    et al.
    Department of Occupational and Environmental Medicine, Sahlgrenska Academy at Göteborg University, Göteborg.
    Sunesson, Anna-Lena
    Department of Work and the Physical Environment, National Institute for Working Life, Umeå.
    Sundgren, Margit
    Department of Work and the Physical Environment, National Institute for Working Life, Umeå.
    Levin, Jan-Olof
    Department of Work and the Physical Environment, National Institute for Working Life, Umeå.
    Sällsten, Gerd
    Department of Occupational and Environmental Medicine, Sahlgrenska Academy at Göteborg University, Göteborg.
    Barregard, Lars
    Department of Occupational and Environmental Medicine, Sahlgrenska Academy at Göteborg University, Göteborg.
    Field evaluation of two diffusive samplers and two adsorbent media to determine 1,3-butadiene and benzene levels in air2006Inngår i: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 40, nr 40, s. 7686-7695Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two types of diffusive samplers, both of which are compatible with thermal desorption, but differ in their geometry-SKC-Ultra (badge-type) and Radiello (radial symmetry-type)-were evaluated indoors and outdoors under varying temperature, humidity and wind speed conditions, using the graphitized adsorbents Carbopack X or Carbograph 5 to measure 1,3-butadiene and benzene in ambient air. The results obtained by diffusive sampling were compared with results obtained using a conventional active sampling method over both long (1 week) and shorter periods (6-24 h). Analysis and detection were performed using an automatic thermal desorber (ATD) connected to a gas chromatograph-flame ionization detector (GC/FID). Results from each sampler and adsorbent combination were examined using ordinary or multiple linear regression analysis. The overall uncertainty (OU) was also determined. In general, the results obtained with both samplers showed good agreement with those obtained by active sampling. Carbopack X appeared to be a more efficient adsorbent than Carbograph 5 for 1,3-butadiene, but the two adsorbents were equivalent for benzene. No effects of either humidity or air velocity were observed. Minor temperature effects were observed for both samplers for 1,3-butadiene. In summary, the results confirmed the accuracy of sampling rates previously determined for the two samplers and adsorbents. We consider the two samplers to be suitable for stationary and personal monitoring for the general population of 1,3-butadiene and benzene in various environments, indoors and outdoors. They are almost independent of meteorological conditions and may be suitable for monitoring industrial atmospheres.

  • 1254.
    Strawhacker, Colleen
    et al.
    University of Colorado, Boulder, CO USA.
    Buckland, Philip I.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet. Umeå universitet, Humanistiska fakulteten, Humlab.
    Palsson, Gisli
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet. Umeå universitet, Humanistiska fakulteten, Humlab.
    Fridrikkson, Adolf
    Institute of Archaeology, Reykjavik, Iceland.
    Lethbridge, Emily
    Centre for Medieval Studies, University of Iceland, Reykjavik, Iceland.
    Brin, Adam
    Arizona State University, Tempe, USA.
    Opitz, Rachel
    University of Arkansas, Fayetteville, USA.
    Dawson, Thomas
    School of History, St. Andrews University, Scotland.
    Building Cyberinfrastructure from the Ground Up for the North Atlantic Biocultural Organization: Introducing the cyberNABO Project2015Inngår i: 2015 Digital Heritage: Volume 2 / [ed] Gabriele Guidi, Roberto Scopigno, Juan Carlos Torres, Holger Graf et al., Institute of Electrical and Electronics Engineers (IEEE), 2015, Vol. 2, s. 457-460, artikkel-id 7419547Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The cyberNABO Project is designed to solidify a developing multidisciplinary community through the development of cyberinfrastructure (CI) to study the long-term human ecodynamics of North Atlantic, a region that is especially vulnerable to ongoing climate and environmental change. It builds build upon prior sustained field and laboratory research, rich and diverse datasets, and a strong involvement by local communities and institutions. cyberNABO is currently hosting a series of workshops aimed at taking these collaborators and stakeholder communities to a new level of integration and to develop capacity for building CI and visualizations in subsequent funding cycles. Research on the long-term sustainability in the Arctic requires compiling data from over thousands of square miles, hundreds of years, and multiple disciplines, from climatology to archaeology to folklore. The complexity of datasets of this scale presents a unique challenge to create a CI system that results in interoperability and accessibility of data – a task that needs an explicit plan and extensive expertise from a variety of fields. Investing in a comprehensive CI system provides the opportunity to integrate collaborators and data from the natural sciences, social sciences, and the humanities, thus providing the opportunity for a holistic approach to long-term human ecodynamics in the context of rapid social and environmental change and for the creation of digital tools for expanded northern community involvement in global change research. In order to address questions of this scale, however, this collaborative group needs to integrate multiple sources, types, and formats of data to address multidisciplinary questions and provide effective support for visualization and modeling efforts that can connect knowledge systems.

  • 1255.
    Strengbom, Joachim
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Nitrogen, parasites and plants: key interactions in boreal forest ecosystems2002Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In the work described in this thesis I studied how increases in nitrogen (N) inputs may affect plant community structure in boreal forest understorey vegetation. These phenomena were investigated in N fertilization experiments and along a national N deposition gradient. After five years of N additions, large changes in understorey vegetation composition were observed in the fertilization study. In plots that received 50 kg N ha'1 year"1 (N2), the abundance of the dominant species, Vaccinium myrtillus, decreased on average by 32 %. No decrease was observed in control plots during the same period. In contrast, the grass Deschampsia flexuosa responded positively to increased N input, being on average more than five times as abundant in the N2 treatments as in controls.

    Also an increase was seen in the incidence of disease caused by the parasitic fungus Valdensia heterodoxa on leaves of V. myrtillus following N additions. The parasite was on average nearly twice as abundant in N2 plots than in control plots. This could be explained by increased N concentrations in host plant tissue. Disease incidence also increased following experimental additions of glutamine to leaf surfaces of V. myrtillus, suggesting a causal connection between plant N concentration and performance of the fungus. The parasite also played a key role in the observed changes in understorey species composition. D. flexuosa was more abundant in patches in which V. myrtillus was severely affected by V heterodoxa. This suggests that V heterodoxa mediates the increased abundance of D. flexuosa following increased N additions. The fungus mediates changes in the composition of understorey vegetation mainly by increasing light availability via premature leaf loss of V. myrtillus.

    The incidence of disease due to the parasite was on average higher in large than in smaller N-treated plots, indicating that the response to N fertilization is spatially scale dependent. This shows that using small plot sizes in experiments that simulate changed environmental conditions may be problematic, as important interactions may be underestimated.

    Comparison of the occurrence of understorey species between regions with different rates of N deposition revealed that the occurrence of the two dwarf shrubs V. myrtillus and V. vitis- idaea was lower in regions with high N deposition compared to regions with low deposition. The opposite pattern was found for V heterodoxa. This is consistent with expectations from N fertilization experiments. For D. flexuosa no differences in occurrence were found between the different regions investigated.

    The effects on vegetation and mycorrhizal fungi observed following N additions were also found to be long lasting. Nine years after termination of the fertilization, no signs of recovery were detected, and nearly 50 years after termination characteristic signs of N fertilization were found among bryophytes and mycorrhizal fungi. This suggests that the time needed for re-establishment of the original biota following N-induced changes may be substantial.

  • 1256.
    Ström, Lotta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jansson, Roland
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Projected changes in plant species richness and extent of riparian vegetation belts as a result of climate-driven hydrological change along the Vindel River in Sweden2012Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 57, nr 1, s. 49-60Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. Riparian plant communities are primarily structured by the hydrological regime of the stream. Models of climate change predict increased temperatures and changed patterns of precipitation that will alter the flow of rivers and streams with consequences for riparian communities. In boreal regions of Europe, stream flows will exhibit earlier spring-flood peaks of lower magnitude, lower summer flows and higher flows in autumn and winter. We quantified the effects of predicted hydrological change on riparian plant species richness, using four different scenarios for the free-flowing Vindel River in northern Sweden.

    2. We calculated the hydrological niche of vegetation belts by relating the occurrence of species and vegetation belts to data on flood duration for 10 years preceding the vegetation survey. We then used the flood duration predicted for 2071–2100 to estimate expected changes in the extent of each vegetation belt. Using species accumulation curves, we then predicted changes in plant species richness as a result of changes in extent.

    3. The two most species-rich vegetation belts, riparian forest and willow shrub, were predicted to decrease most in elevational extent, up to 39 and 32%, respectively. The graminoid belt below the shrub belt will mainly shift upwards in elevation while the amphibious vegetation belt at the bottom of the riparian zone increases in size.

    4. In the Vindel River, the riparian forest and willow shrub zone will lose most species, with reductions of 5–12% and 1–13% per site, respectively, depending on the scenario. The predicted loss from the entire riparian zone is lower, 1–9%, since many species occur in more than one vegetation belt. More extensive species losses are expected in the southern boreal zone for which much larger spring-flood reductions are projected.

    5. With an expected reduction in area of the most species-rich belts, it becomes increasingly important to manage and protect riparian zones to alleviate other threats, thus minimising the risk of species losses. Restoring river and stream reaches degraded by other impacts to gain riparian habitat is another option to avoid species losses.

  • 1257.
    Stål, Herman
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Företagsekonomi.
    Bonnedahl, Karl Johan
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Företagsekonomi.
    Provision of Climate Advice as a Mechanism for Environmental Governance in Swedish Agriculture2015Inngår i: Environmental Policy and Governance, ISSN 1756-932X, E-ISSN 1756-9338, Vol. 25, nr 5, s. 356-371Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate mitigation is both a pressing and complex task, and one that frequently requires both participation to involve stakeholders and capacity building to enable them to change their practices. This paper considers whether the provision of climate advice to affected parties could be an effective policy activity in both respects. The article investigates the feasibility and potential influence of providing climate advice by examining the role that such advice has played in the discursive activities of agriculture extension consultants in Sweden. This case demonstrates that, rather than promoting substantial change in practices, the climate issue is used to support conventional efficiency-increasing measures and to change the descriptions of prevailing agricultural activities. We find that the embedding of climate related discourse within agricultural extension and the lack of clear climate mitigation goals for the agricultural sector reduced and adapted the climate issue to enable it to be easily accommodated in the narratives prevailing among farmers, which are well aligned with conventional economic, rather than climate, policy goals. This lock-in could be addressed by establishing clear and radical reduction targets and through the broader involvement of a wider range of stakeholders.

  • 1258.
    Sullivan, Alexis R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. School of Forest Resources and Environmental Science, Michigan Technological Univ., 1400 Townsend Drive, Houghton, MI 49931, USA.
    Flaspohler, David J.
    Froese, Robert E.
    Ford, Daena
    Climate variability and the timing of spring raptor migration in eastern North America2016Inngår i: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 47, nr 2, s. 208-218Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many birds have advanced their spring migration and breeding phenology in response to climate change, yet some long-distance migrants appear constrained in their adjustments. In addition, bird species with long generation times and those in higher trophic positions may also be less able to track climate-induced shifts in food availability. Migratory birds of prey may therefore be particularly vulnerable to climate change because: 1) most are long-lived and have relatively low reproductive capacity, 2) many feed predominately on insectivorous passerines, and 3) several undertake annual migrations totaling tens of thousands of kilometers. Using multi-decadal datasets for 14 raptor species observed at six sites across the Great Lakes region of North America, we detected phenological shifts in spring migration consistent with decadal climatic oscillations and global climate change. While the North Atlantic and El Nino Southern Oscillations exerted heterogeneous effects on the phenology of a few species, arrival dates more generally advanced by 1.18 d per decade, a pattern consistent with the effects of global climate change. After accounting for heterogeneity across observation sites, five of the 10 most abundant species advanced the bulk of their spring migration phenology. Contrary to expectations, we found that long-distance migrants and birds with longer generation times tended to make the greatest advancements to their spring migration. Such results may indicate that phenotypic plasticity can facilitate climatic responses among these long-lived predators.

  • 1259.
    Sundelin, Anna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Psychotherapeutic drugs in lake sediment: Accumulation and persistence of benzodiazepines in the sediment of Lake Ekoln2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Benzodiazepines are the most commonly prescribed group of psychotherapeutic pharmaceuticals on a global scale and have been on the market since the 1960s. Benzodiazepines remain in the aqueous effluent from sewage treatment plants and have been found in natural aquatic environments. The aim of this study was to investigate if there is benzodiazepines in natural sediment from Lake Ekoln situated downstream River Fyris in Uppsala, where previous studies have detected high concentrations in the water. The study tested following hypotheses: (1) benzodiazepines are accumulating in sediments; and (2) breakdown of benzodiazepines is slow in sediment resulting in them being preserved in sediments that are several years/decades old. An extraction method for sediment was developed followed by liquid chromatography-tandem mass spectrometry for analysis of oxazepam, alprazolam, clonazepam, flunitrazepam, diazepam and prazepam. All investigated benzodiazepines occurred in the sediment of Lake Ekoln; hence, in line with hypothesis 1, benzodiazepines are accumulating in natural sediments. Further, all benzodiazepines were found in the upper 10 cm of the sediment and oxazepam, clonazepam and diazepam was found at depth below 20 cm, corresponding to an age of more than 20 years indicating that benzodiazepines resists degradation processes in sediment and are persistent for decades as predicted by hypothesis 2. To my knowledge this is the first study demonstrating that benzodiazepines are accumulated and preserved in natural sediments.

  • 1260.
    Sundin, Joe
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Seed rain and dispersal possibilities between process domains: Comparing seed dispersal abundance between lakes, rapids and slow-flowing reaches2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Process domains are formed by geomorphological process, these geological formation act as water pathways for river systems and affects hydrochory potential for seeds. Hydrochory acts differently depending on fluvial settings and is an important factor for diversity in the riparian zone along streams and lakes. The aim of this study was to (1) determine if process domains influence plant species abundance and diversity, and (2) if certain environmental factors associated with different process domains affects species abundance and diversity. The sample sites are parts of a dendritic water system located in tributaries for Hjuksån summer 2017 in northern Sweden. Seed samples were collected from three process domains (lake, rapids and slow-flowing) and later identified in lab. A greater species abundances and seed amount were found at lakes compared to rapids and slow-flowing reaches but there were no significant different between the process domains. None of the environmental factors showed to be important but there were indications that number of boulders might influence seed dispersal. Shannon Diversity index showed to be highest along slow-flowing reaches, but again no significant difference. Understanding process domains and their unique compositions in species abundance and diversity is for example an important factor for restoration techniques of anthropogenic modified streams.

  • 1261. Sundin, Josefin
    et al.
    Jutfelt, Fredrik
    Thorlacius, Magnus
    Fick, Jerker
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Brodin, Tomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Behavioural alterations induced by the anxiolytic pollutant oxazepam are reversible after depuration in a freshwater fish2019Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 665, s. 390-399Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anthropogenic pharmaceutical pollutants have been detected in nature across the globe, and recent work has shown negative effects of pharmaceuticals on the health and welfare of many animals. However, whether alterations can be reversed has been poorly investigated, although such studies are essential to assess the effects of high-peak exposure events in waterways where pharmaceutical concentrations are usually low. In this study, we investigated the effects of two concentrations (environmentally relevant 1 μg L−1 and high 100 μg L−1) of oxazepam, an anxiolytic commonly detected in aquatic environments, and whether behavioural alterations are reversible after depuration. Specifically, we measured daytime and night-time swimming activity and daytime behaviours related to boldness (foraging, sheltering and routine swimming activity) using the freshwater burbot (Lota lota). We found that both swimming activity and boldness were affected by oxazepam. Fish exposed to the higher level had a higher burst swimming duration (i.e., fast swimming bouts), both in the daytime and night-time trials. Further, fish exposed to the lower oxazepam level spent less time sheltering than control- and high-level exposed fish, but there was no difference between the control and high oxazepam treatments. For routine swimming activity, quantified in the boldness trials, and for latency to forage, there were no treatment effects. When retesting the fish after depuration, the detected behavioural alterations were no longer present. Since the magnitude of these effects were not consistent across endpoints, our study suggests that oxazepam might not be a great concern for this particular, stress tolerant, species, highlighting the importance of evaluating species-specific effects of pharmaceuticals. The observation that the effects we did find were reversible after depuration is encouraging, and indicates that rapid restoration of behaviours after removal from oxazepam contamination is possible.

  • 1262.
    Sundman, Anneli
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Interactions between Fe and organic matter and their impact on As(V) and P(V)2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Iron (Fe) speciation is important for many biogeochemical processes. The high abundance and limited solubility of Fe(III) are responsible for the widespread occurrence of Fe(III) minerals in the environment. Co-precipitation and adsorption onto mineral surfaces limits the free concentrations of compounds such as arsenate (As(V)), Fe(III) and, phosphate (P(V)). Mineral dissolution, on the other hand, might lead to elevated concentrations of these compounds. Fe speciation is strongly affected by natural organic matter (NOM), which suppresses hydrolysis of Fe(III) via complexation. It limits the formation of Fe(III) minerals and Fe(III) co-precipitation. This thesis is focused on interactions between Fe(III) and NOM as well as their impact on other elements (i.e. As(V) and P(V)). X-ray absorption spectroscopy (XAS) was used to obtain molecular scale information on Fe and As speciation. This was complemented with infrared spectroscopy, as well as traditional wet-chemical analysis, such as pH and total concentration determinations. Natural stream waters, soil solutions, ground water and soil samples from the Krycklan Catchment, in northern Sweden, were analyzed together with model compounds with different types of NOM. A protocol based on ion exchange resins was developed to concentrate Fe from dilute natural waters prior to XAS measurements. Iron speciation varied between the stream waters and was strongly affected by the surrounding landscape. Stream waters originating from forested or mixed sites contained both Fe(II, III)-NOM complexes and precipitated Fe(III) (hydr)oxides. The distribution between these two pools was influenced by pH, total concentrations and, properties of NOM. In contrast, stream waters from wetland sites and soil solutions from a forested site only contained organically complexed Fe. Furthermore, the soil solutions contained a significant fraction Fe(II)-NOM complexes. The soil samples were dominated by organically complexed Fe and a biotite-like phase. Two pools of Fe were also identified in the ternary systems with As(V) or P(V) mixed with Fe(III) and NOM: all Fe(III) was complexed with NOM at low total concentrations of Fe(III), As(V) and/or P(V). Hence, Fe(III) complexation by NOM reduced Fe(III)-As(V)/P(V) interactions at low Fe(III) concentrations, which led to higher bioavailability. Exceeding the Fe(III)-NOM complex equilibrium resulted in the occurrence of Fe(III)-As(V)/P(V) (co-)-precipitates.

  • 1263.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Laudon, Hjalmar
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Centre for Environmental and Climate Research & Department of Biology, Lund University, Lund.
    XAS study of iron speciation in soils and waters from a boreal catchment2014Inngår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 364, s. 93-102Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Iron (Fe) is a key element, strongly influencing the biogeochemistry of soils, sediments and waters, but the knowledge about the variety of Fe species present in these systems is still limited. In this work we have used X-ray absorption spectroscopy (XAS) to study the speciation of Fe in soils and waters from a boreal catchment in northern Sweden. The aim was to better understand the controls of Fe speciation across different, but adjacent landscape elements including soil, soil solution, groundwater and stream water draining catchments with contrasting land characteristics. Our results showed that all samples contained mixtures of Fe(II) and Fe(III). The soils consisted of Fe phyllosilicates, Fe (hydr)oxides and Fe complexed by natural organic matter (NOM). All aqueous samples contained Fe(II)– and Fe(III)–NOM complexes, often in combination with Fe(III) (hydr)oxides that were associated with NOM. The variation in contribution from Fe–NOM and Fe (hydr)oxides was controlled by pH and total concentrations of NOM. The XAS spectra suggested formation of mononuclear Fe–NOM complexes consisting of chelate ring structures, but it could not be determined whether they originated solely from Fe(III)– or from a mixture of Fe(II)/Fe(III)–NOM complexes. Our collective results showed that the Fe speciation was highly variable across the different landscape elements and streams. This variation was manifested both in the distribution between mononuclear Fe–NOM complexes and Fe (hydr)oxides associated with NOM and between Fe(II) and Fe(III). These results highlight the complexity of Fe speciation in natural environmental systems and thus the challenges in interpreting Fe reactivity.

  • 1264.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Centre for Environmental and Climate Research & Department of Biology, Lund University.
    An experimental protocol for structural characterization of Fe in dilute natural waters2013Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, nr 15, s. 8557-8564Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The properties of iron (Fe) complexes and compounds in the environment influence several central processes, e.g., iron uptake, adsorption/desorption of contaminants and nutrients, and redox transformations, as well as the fate of of natural organic matter (NOM). It is thus important to characterize Fe species in environmental samples. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy has been used in several studies on soils and sediments, but literature is scarce on investigations of natural waters because of low Fe concentrations. In this study we have described a gentle and noninvasive preconcentration method, based on electrostatic adsorption onto ion-exchange resins, suitable for EXAFS analysis of Fe species in dilute stream water samples. The EXAFS results of metal-organic model complexes showed that no significant local structural distortions were induced by the method. We also demonstrated the feasibility for an 8 μM Fe stream water sample. The Fe heterogeneity in this stream water was investigated via a gradient series at 28%, 42%, 77%, 84%, and 100% adsorption of total iron. The EXAFS results showed that Fe(III) in this stream water was divided into Fe(III)-NOM complexes and Fe(III) (oxyhydr)oxides associated with NOM, and that each class consisted of several subspecies.

  • 1265.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Centre of Environmental and Climate Research & Department of Biology, Lund University.
    Reactivity of Fe from a natural stream water towards As(V)Manuskript (preprint) (Annet vitenskapelig)
  • 1266.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Sjöberg, Staffan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Centre of Environmental and Climate Research & Department of Biology, Lund University.
    Complexation and precipitation reactions in the ternary As(V)-Fe(III)-NOM (natural organic matter) systemManuskript (preprint) (Annet vitenskapelig)
  • 1267.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Sjöberg, Staffan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per
    Complexation and precipitation reactions in the ternary As(V)–Fe(III)–OM (organic matter) system2014Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 145, s. 297-314Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The predominant forms of arsenic (As) in anoxic and oxic environments are As(III) and As(V), respectively, and the fate of these forms is influenced by interactions with mineral surfaces and organic matter (OM). Interactions between As(V) and OM are believed to occur mainly via iron(Fe)-bridges in ternary Fe–arsenate complexes, but direct evidence for these interactions are scarce. Furthermore, since the speciation of Fe in the presence of organic matter varies as a function of pH and Fe concentration, a central question is how different chemical conditions will affect the As–Fe–OM interactions. In order to answer this, the As(V)–Fe(III)–OM system have been studied under a large range of experimental conditions (6485–67,243 ppm Fe(III) and Fe(III):As(V) ratios of 0.5–20 at pH 3–7), with Suwannee River natural organic matter and Suwannee River fulvic acid as sources of OM, using Fe and As K-edge X-ray absorption spectroscopy (XAS), infrared (IR) spectroscopy and chemical equilibrium modeling. Our collective results showed that interactions in the ternary As(V)–Fe(III)–OM system were strongly influenced by pH, total concentrations and ratios among the reactive species. In particular, the high stability of the Fe(III)–OM complexes exerted a strong control on the speciation. The predominant species identified were mononuclear Fe(III)–OM complexes, Fe(III) (hydr)oxides and FeAsO4 solids. The experimental results also showed that at low concentrations the Fe(III)–OM complexes were sufficiently stable to prevent reaction with arsenate. The chemical equilibrium models developed corroborated the spectroscopic results and indicated that As(V) was distributed over two solid phases, namely FeAsO4(s) and Fe(OH)1.5(AsO4)0.5(s). Thus, neither ternary As(V)–Fe(III)–OM complexes nor As(V) surface complexes on Fe(III) (hydr)oxides were necessary to explain the collective results presented in this study.

  • 1268.
    Sundman, Anneli
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Torbjörn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Sjöberg, Staffan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Centre of Environmental and Climate Research & Department of Biology, Lund University.
    Complexation and precipitation reactions in the ternary P(V)-Fe(III)-NOM (natural organic matter) systemManuskript (preprint) (Annet vitenskapelig)
  • 1269.
    Sundqvist, Kristina
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Sources of dioxins and other POPs to the marine environment: Identification and apportionment using pattern analysis and receptor modeling2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In the studies underlying this thesis, various source tracing techniques were applied to environmental samples from the Baltic region.

    Comprehensive sampling and analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surface sediments in Swedish coastal and offshore areas resulted in a unique data set for this region. Nearly 150 samples of surface sediments were analyzed for all tetra- to octa-chlorinated PCDD/Fs. The levels showed large spatial variability with hotspots in several coastal regions. Neither Sweden nor the EU has introduced guideline values for PCDD/Fs in sediment, but comparisons to available guidelines and quality standards from other countries indicate that large areas of primarily coastal sediments may constitute a risk to marine organisms.

    Multivariate pattern analysis techniques and receptor models, such as Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF), were used to trace sources. These analyses suggested that three to six source types can explain most of the observed pattern variations found in the sediment samples. Atmospheric deposition was suggested as the most important source to offshore areas, thus confirming earlier estimates. However, spatial differences indicated a larger fraction of local/regional atmospheric sources, characterized by PCDFs, in the south. This was indicated by the identification of several patterns of atmospheric origin. In coastal areas, the influence of direct emission sources was larger, and among these, chlorophenol used for wood preservation and emissions from pulp/paper production and other wood related industry appeared to be most important. The historic emissions connected to processes involving chemical reactions with chlorine (e.g. pulp bleaching) were found to be of less importance except at some coastal sites.

    The analysis of PCDD/Fs in Baltic herring also revealed spatial variations in the levels and pollution patterns along the coast. The geographical match against areas with elevated sediment levels indicated that transfer from sediments via water to organisms was one possible explanation.

    Fugacity, a concept used to predict the net transport direction between environmental matrices, was used to explore the gas exchange of hexachlorocyclohexanes (HCHs) and polychlorinated biphenyls (PCBs) between air and water. These estimates suggested that, in the Kattegat Sea, the gaseous exchange of HCHs primarily resulted in net deposition while PCBs were net volatilized under certain environmental conditions. The study also indicated that, while the air concentrations of both PCBs and γ-HCH are mostly dependent upon the origin of the air mass, the fluctuations in α-HCH were primarily influenced by seasonal changes.

     

  • 1270.
    Sundqvist, Kristina
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Cato, Ingemar
    Division of Geophysic and Marine Geology, Geological Survey of Sweden.
    Bignert, Anders
    The Swedish Museum of Natural History, Stockholm, Sweden.
    Wiberg, Karin
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Levels and homologue profiles of PCDD/Fs in sediments along the Swedish coast of the Baltic Sea2009Inngår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 16, nr 4, s. 396-409Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background, aim, and scope  The primary aim of this study was to explore the variations in PCDD/F levels and homologue profiles of Baltic surface sediments by comprehensively analyzing polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in samples from a large number of sites, encompassing not only previously known hotspot areas, but also sites near other potential PCDD/F sources, in pristine reference areas (in which there was no industrial activity) and offshore sites. Materials and methods  Surface sediment samples (146 in total) were collected at various points along the Swedish coast and offshore areas. In addition, bulk deposition was sampled, monthly, at a single site in northern Sweden during 1 year. The concentrations of tetra- through octa-substituted CDD/Fs were determined in both matrices. Results  Highly elevated concentrations of PCDD/Fs were found at many sites in coastal areas and concentrations were also slightly elevated in some offshore areas. Homologue profiles varied substantially amongst samples from coastal sites, while those from offshore and other pristine sediments were relatively similar. The offshore sediments showed different profiles from those observed in the deposition samples. Sediment levels of PCDD/Fs were not generally significantly correlated to organic carbon levels, except in some pristine areas. Comparison of data obtained in this and previous studies suggest that both their levels and profiles are similar today to those observed 20 years ago in coastal and offshore areas. The only detected trend is that their levels appear to have decreased slightly in the offshore area of the Bothnian Sea. Discussion  The localization of hotspot areas along the coast, the lack of consensus between PCDD/F profiles of sediments and general background, and their weak correlations with organic carbon suggest that PCDD/Fs in the study area largely originate from local/regional emissions. However, due to complicating factors such as sediment dynamics and land upheaval, it is not possible to conclude whether these pollutants derive from recent emissions or from a combination of recent emissions and re-distribution of previous inputs. Conclusions  The results show that: elevated levels of PCDD/Fs are present in both coastal and offshore areas of the Baltic Sea, the major hotspots are close to the shore, and there are large variations in profiles, indicating that local emissions are (or have been) the major causes of pollution. Recommendations and perspectives  In order to identify other hotspot areas and trace sources, comprehensive analysis of PCDD/Fs in surface sediments is needed in all areas of the Baltic Sea that have not been previously investigated. The high levels of PCDD/Fs observed in surface sediments also indicate a need to elucidate whether they are due mainly to current emissions or a combination of recent pollution and re-distribution of historically deposited pollutants. To do so, better understanding of sediment dynamics and present-day inputs, such as riverine inputs, industrial effluents, and leakage from contaminated soil is required. There are indications that contaminated sediments have a regional impact on fish contamination levels. However, as yet there is no statistically robust evidence linking contaminated sediments with elevated levels in Baltic biota. It should also be noted that the Baltic Sea is being massively invaded by the deep-burrowing polychaete Marenzielleria ssp., whose presence in sediments has been shown to increase water concentrations of hydrophobic pollutants. In awareness of this, it is clear that high levels in sediments cannot be ignored in risk assessments. In order to investigate the emission trends more thoroughly, analysis of PCDD/Fs in offshore sediment cores throughout the Baltic Sea is also recommended. Electronic supplementary material  The online version of this article (doi:10.1007/s11356-009-0110-z) contains supplementary material, which is available to authorized users.

  • 1271.
    Sundqvist, Kristina
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Geladi, Paul
    Unit of Biomass Technology and Chemistry, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Cato, Ingemar
    Division of Geophysic and Marine Geology, Geological Survey of Sweden, Uppsala, Sweden.
    Wiberg, Karin
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Congener fingerprints of tetra- through octa-chlorinated dibenzo-p-dioxins and dibenzofurans in Baltic surface sediments and their relations to potential sources2009Inngår i: Chemosphere, Vol. 77, nr 5, s. 612-20Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Comprehensive congener fingerprints of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), including non-2,3,7,8-substituted congeners, in 142 surface sediment samples from the Baltic Sea were characterized by Principal Component Analysis (PCA). The pattern analysis revealed source specific indicators of chlorophenol use, high temperature processes, chlorine bleach/chloralkali production and a source signature suggested to originate from pulp/paper or related production. Congener patterns in sediments from offshore and pristine coastal areas showed strong resemblance to patterns of atmospheric deposition and flue gases, indicating that these sources have high impact in areas that are not affected by point sources. Prominent contributors to the patterns of hotspot areas along the Swedish coast included chlorophenol indicators and a source characterized by hexa-CDDs while the contribution of the traditional chlorine bleach pattern was weaker. This study demonstrates the importance of comprehensive PCDD/F congener analysis for identifying links to candidate sources.

  • 1272.
    Sundqvist, Kristina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Geladi, Paul
    Unit of Biomass Technology and Chemistry, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Hopke, Philip
    Department of Chemical and Biomolecular Engineering and Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY, USA.
    Wiberg, Karin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    PCDD/F Source Apportionment in the Baltic Sea Using Positive Matrix Factorization2010Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 44, nr 5, s. 1690-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Positive Matrix Factorization (PMF) was used to identify and apportion candidate sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in samples of offshore and coastal surface sediments from the Baltic Sea. Atmospheric deposition was the dominant source in offshore and pristine areas, in agreement with previous studies. Earlier chlorophenol use and a source suggested origins from pulp and paper production and related industries were identified as important coastal sources. A previously presumed major source, chlorine bleaching of pulp, was of only minor importance for modern Baltic surface sediments. The coastal source impacts were mostly local or regional, but pattern variations in offshore samples indicate that coastal sources may have some importance for offshore areas. Differences between sub-basins also indicated that local and regional air emissions from incineration or other high-temperature processes are more important in the southern Baltic Sea compared to those in northerly areas. These regional differences demonstrated the importance of including offshore sediments from the Bothnian Bay, Gulf of Finland, and other areas of the Baltic Sea in future studies to better identify the major PCDD/F sources to the Baltic Sea.

  • 1273.
    Sundqvist, Kristina
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Wingfors, Håkan
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Brorström-Lundén, Eva
    Swedish Environmental Research Institute, Gothenburg, Sweden.
    Wiberg, Karin
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Kemi.
    Air-sea gas exchange of HCHs and PCBs and enantiomers of α-HCH in the Kattegat Sea region2004Inngår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 128, s. 73-83Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Concentrations and air–water gas exchange of polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCHs) were determined in nine paired air and water samples. The samples were collected monthly in the Kattegat Sea between December 1998 and November 1999. Average fugacity and flux values indicated that PCBs were oversaturated in the water, while HCHs were net deposited. Variations were large over the year, especially during spring and summer. Air parcel back trajectories suggested that air concentrations over the Kattegat Sea are largely dependent of air mass origin. Seasonal trends were detected for airborne HCHs and for PCBs in water. The air and water enantiomeric compositions of α-HCH indicated that a larger portion of α-HCH in air originated from the underlying water during summer than during winter.

  • 1274.
    Sundqvist, Maja
    et al.
    Institutionen för skogens ekologi och skötsel, SLU, Umeå.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wardle, David
    Institutionen för skogens ekologi och skötsel, SLU, Umeå.
    Höjdgradienter hjälper oss att förstå den globala uppvärmningens påverkan i Arktis2013Rapport (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Framtidens temperaturökningar orsakade av den globala uppvärmningen förväntas vara högst på högre breddgrader. Arktis ekosystem, där växtligheten är starkt begränsad av både låga temperaturer och låg näringstillgänglighet, är troligtvis också väldigt känsliga för denna temperaturökning. Mycket forskning i Arktis syftar till att förstå hur ekosystemen kommer att påverkas av framtida klimatförändringar och konsekvenserna av dessa för viktiga natur- och samhällsvärden. Eftersom temperaturen sjunker med ökad höjd har biologer länge använt sig av höjdgradienter för att studera hur växt- och djursamhällen påverkas av naturliga variationer i temperatur. Fjällen kring Abisko i norra Sverige erbjuder därför möjligheter för en ökad förståelse av hur Arktis växtlighet kan komma att påverkas av framtida klimatförändringar. Under 2007 och 2008 påbörjades undersökningar av förändringar i artsammansättning och näringsstatus (kväve och fosfor) för fattig hed och rikare ängsvegetation längs en höjdgradient (500–1000 meter) i närheten av Abisko, nordligaste Sverige. Temperaturen i mitten av sommaren sjunker med ungefär 0,6° per 100 meter höjdökning eller 3°C från den lägsta till högsta höjden längs den här gradienten. Artsammansättningen förändras mer för ängsvegetation än för hedvegetationen längs höjdgradienten. Växtsamhället under 2008 innehöll även mindre kväve relativt fosfor på de lägre (varmare) höjderna än på de högre och kallare höjderna. Förändringen i kväve- och fosforkvoter var också större för ängsvegetationen. Detta tyder på att förändringar i växtsamhällens artsammansättning, näringsstatus och näringsbegränsning med ökade temperaturer i Arktis kommer att skilja sig markant åt mellan rik och fattig vegetation.

  • 1275. Sundqvist, Maja K.
    et al.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Graae, Bente J.
    Wallander, Håkan
    Fogelberg, Elisabeth
    Wardle, David A.
    Interactive effects of vegetation type and elevation on aboveground and belowground properties in a subarctic tundra2011Inngår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 120, nr 1, s. 128-142Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An improved knowledge of how contrasting types of plant communities and their associated soil biota differ in their responses to climatic variables is important for better understanding the future impacts of climate change on terrestrial ecosystems. Elevational gradients serve as powerful study systems for answering questions on how ecological processes can be affected by changes in temperature and associated climatic variables. In this study, we evaluated how plant and soil microbial communities, and abiotic soil properties, change with increasing elevation in subarctic tundra in northern Sweden, for each of two dominant but highly contrasting vegetation types, namely heath (dominated by woody dwarf shrubs) and meadow (dominated by herbaceous species). To achieve this, we measured plant community characteristics, microbial community properties and several soil abiotic properties for both vegetation types across an elevation gradient of 500 to 1000 m. We found that the two vegetation types differed not only in several above- and belowground properties, but also in how these properties responded to elevation, pointing to important interactive effects between vegetation type and elevation. Specifically, for the heath, available soil nitrogen and phosphorus decreased with elevation whereas fungal dominance increased, while for the meadow, idiosyncratic responses to elevation for these variables were found. These differences in belowground responses to elevation among vegetation types were linked to shifts in the species and functional group composition of the vegetation. Our results highlight that these two dominant vegetation types in subarctic tundra differ greatly not only in fundamental aboveground and belowground properties, but also in how these properties respond to elevation and are therefore likely to be influenced by temperature. As such they highlight that vegetation type, and the soil abiotic properties that determine this, may serve as powerful determinants of how both aboveground and belowground properties respond to strong environmental gradients.

  • 1276.
    Sundqvist, Maja K.
    et al.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wardle, David A
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Within- and across-species responses of plant traits and litter decomposition to elevation across contrasting vegetation types in subarctic tundra2011Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, nr 10, s. e27056-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Elevational gradients are increasingly recognized as a valuable tool for understanding how community and ecosystem properties respond to climatic factors, but little is known about how plant traits and their effects on ecosystem processes respond to elevation. We studied the response of plant leaf and litter traits, and litter decomposability across a gradient of elevation, and thus temperature, in subarctic tundra in northern Sweden for each of two contrasting vegetation types, heath and meadow, dominated by dwarf shrubs and herbaceous plants respectively. This was done at each of three levels; across species, within individual species, and the plant community using a community weighted average approach. Several leaf and litter traits shifted with increasing elevation in a manner consistent with greater conservation of nutrients at all three levels, and the most consistent response was an increase in tissue N to P ratio. However, litter decomposition was less directly responsive to elevation because the leaf and litter traits which were most responsive to elevation were not necessarily those responsible for driving decomposition. At the community level, the response to elevation of foliar and litter traits, and decomposability, varied greatly among the two vegetation types, highlighting the importance of vegetation type in determining ecological responses to climatic factors such as temperature. Finally our results highlight how understanding the responses of leaf and litter characteristics of functionally distinct vegetation types, and the processes that they drive, to temperature helps provide insights about how future climate change could affect tundra ecosystems.

  • 1277.
    Sundqvist, Maja K.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Swedish Univ Agr Sci, Dept Forest Ecol & Management, SE-90183 Umea, Sweden.
    Liu, Zhanfeng
    Chinese Acad Sci, South China Bot Garden, Key Lab Vegetat Restorat & Management Degraded Ec, Guangzhou 510650, Guangdong, Peoples R China.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wardle, David A.
    Swedish Univ Agr Sci, Dept Forest Ecol & Management, SE-90183 Umea, Sweden.
    Plant and microbial responses to nitrogen and phosphorus addition across an elevational gradient in subarctic tundra2014Inngår i: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 95, nr 7, s. 1819-1835Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Temperature and nutrients are major limiting factors in subarctic tundra. Experimental manipulation of nutrient availability along elevational gradients (and thus temperature) can improve our understanding of ecological responses to climate change. However, no study to date has explored impacts of nutrient addition along a tundra elevational gradient, or across contrasting vegetation types along any elevational gradient. We set up a full factorial nitrogen (N) and phosphorus (P) fertilization experiment in each of two vegetation types (heath and meadow) at 500 m, 800 m, and 1000 m elevation in northern Swedish tundra. We predicted that plant and microbial communities in heath or at lower elevations would be more responsive to N addition while communities in meadow or at higher elevations would be more responsive to P addition, and that fertilizer effects would vary more with elevation for the heath than for the meadow. Although our results provided little support for these predictions, the relationship between nutrient limitation and elevation differed between vegetation types. Most plant and microbial properties were responsive to N and/or P fertilization, but responses often varied with elevation and/or vegetation type. For instance, vegetation density significantly increased with N + P fertilization relative to the other fertilizer treatments, and this increase was greatest at the lowest elevation for the heath but at the highest elevation for the meadow. Arbuscular mycorrhizae decreased with P fertilization at 500 m for the meadow, but with all fertilizer treatments in both vegetation types at 800 m. Fungal to bacterial ratios were enhanced by N + P fertilization for the two highest elevations in the meadow only. Additionally, microbial responses to fertilization were primarily direct rather than indirect via plant responses, pointing to a decoupled response of plant and microbial communities to nutrient addition and elevation. Because our study shows how two community types differ in their responses to fertilization and elevation, and because the temperature range across this gradient is similar to 3 degrees C, our study is informative about how nutrient limitation in tundra may be influenced by temperature shifts that are comparable to those expected under climate change during this century.

  • 1278.
    Sundström, Marielle
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Effektiv tillsyn av enskilda avlopp2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 1279.
    Sunesson, Anna-Lena
    et al.
    National Institute for Working Life, Umeå.
    Liljelind, Ingrid
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkesmedicin.
    Sundgren, Margit
    National Institute for Working Life, Umeå.
    Pettersson-Strömbäck, Anita
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi. Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Levin, Jan-Olof
    National Institute for Working Life, Umeå.
    Passive sampling in combination with thermal desorption and gas chromatography as a tool for self-assessment of chemical exposure2002Inngår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 4, nr 5, s. 706-710Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Diffusive samplers for monitoring of air quality are user-friendly devices that can normally be operated by the user himself. Hence these samplers are suitable for self-assessment. Practical and work organisational aspects of self-assessment of chemical exposure were studied in different occupational settings. It was found that the diffusive sampler used in these studies, the Perkin-Elmer tube in combination with thermal desorption, worked well for the purpose and could be correctly handled by the individuals using it. The results from self-assessments agreed well with expert measurements carried out by an occupational hygienist. However, in order to obtain a sustainable system of self-assessment strong organizational support is needed.

  • 1280.
    Svahn, Joacim
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Metal release and mobility in an arctic lake due to artificial drainage: Effects of mining and sulfide oxidation2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The aim of this report was to investigate the potential effects of sulfide oxidation in sediments of an arctic lake, N Luossajärvi, induced by lowered water level. Lake water, potentially contaminated by metals, was pumped into a mine tailings impoundment. The water quality in the receiving water was evaluated to see if the drainage have had an effect on the water quality. Six sediment profiles were sampled. Each profile were divided into 5 cm sections and analyzed for major elements and trace metals. Water chemistry were analyzed at six sites. As, Ni and Cu had high concentrations within undrained sediments, where As levels were classified as highly contaminated (> 27 mg kg-1 dw). Trace metals had strong statistical correlation to each other indicating a common source. The PCA analyzes performed suggests that trace metals are controlled by a common factor and drained sediments showed two additional factors controlling the variance of metals. Water chemistry had overall good status, but As, Cd, Ni and Cu exceeded natural background values. Historical data on the other hand showed no statistical difference from measured values. No effects on water quality could therefore be seen after draining of the lake, proposing high precipitation of metals within the tailing or that metals is still prevailing in the drained sediments. Metal mobility were seen within the drained sediments, where only As and Cd were presumed connected to chemical weathering and where erosion and soil properties seems to be responsible for most metal mobility.

  • 1281.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bolnick, DI
    Intraspecific competition affects the strength of individual specialization: an optimal diet theory method2005Inngår i: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 7, nr 7, s. 993-1012Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Question: Why would individuals that inhabit the same environment choose to feed on different subsets of the available resources?

    Mathematical method: We outline a flexible model that combines phenotypic variation with optimal diet theory and population dynamics. We then apply this model to investigate the role of different types of trade-offs. phenotype diversity and level of competition in determining the degree of individual specialization.

    Key assumptions: The foragers in the model are omniscient and maximize energy intake per time unit.

    Conclusion: Numerical simulations match empirical observations that changes in population density can alter the degree of individual specialization. Forager density and phenotypic variation affected prey densities. which in turn affected forager diet breadth and fitness (energy income). We propose that this feedback can explain the empirical relationship between forager density and the degree of individual specialization in the forager population.

  • 1282.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Eklöv, Peter
    Effects of habitat and food resources on morphology and ontogenetic growth trajectories in perch2002Inngår i: Oecologia, Vol. 131, s. 61-70Artikkel i tidsskrift (Fagfellevurdert)
  • 1283.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Eklöv, Peter
    Genetic variation and phenotypic plasticity: Causes of morphological and dietary variation in Eurasian perch2006Inngår i: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 8, nr 1, s. 37-49Artikkel i tidsskrift (Fagfellevurdert)
  • 1284.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Eklöv, Peter
    Morphology dependent foraging efficiency in perch: a trade-off for ecological specialization?2003Inngår i: Oikos, Vol. 102, s. 273-284Artikkel i tidsskrift (Fagfellevurdert)
  • 1285.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Eklöv, Peter
    Morphology in perch affects habitat specific feeding efficiency2004Inngår i: Functional Ecology, ISSN 0269-8463, E-ISSN 1365-2435, Vol. 18, nr 4, s. 503-510Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]
    • 1. Trophic polymorphism is a common phenomenon in many species. Trade-offs in foraging efficiency on different resources are thought to be a primary cause of such polymorphism.

    • 2.To test for a trade-off in foraging efficiency perch (Perca fluviatilis L.) were used from a population that differs in morphology between the littoral and pelagic habitat of a lake. Indoor aquarium experiments were performed with three different prey types in two different environments. It was predicted that the morphology of the individual would affect foraging efficiency in the different environments and on the different prey types through search and attack behaviour.
    • 3.Overall the foraging efficiency of perch was found to be related to individual morphology. A connection was also found between individual morphology and search and attack behaviour. Search behaviour but not attack behaviour was affected by the structure in the aquaria. Furthermore our results show that there are relations between search behaviour and detection rates and between attack behaviour and attack success.
    • 4.Our results give a mechanistic explanation for the differences in foraging efficiency between littoral and pelagic perch. These differences are probably driven by a functional trade-off between foraging performance and general body form.
  • 1286.
    Svanbäck, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Persson, Lennart
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Individual diet specialization, niche width and population dynamics: implications for trophic polymorphisms2004Inngår i: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 73, nr 5, s. 973-982Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. We studied a perch Perca fluviatilis L. population that during a 9-year period switched between a phase of dominance of adult perch and a phase dominated by juvenile perch driven by cannibalism and intercohort competition. We investigated the effects of these population fluctuations on individual diet specialization and the mechanisms behind this specialization.

    2. Due to cannibalism, the survival of young-of-the-year (YOY) perch was much lower when adult perch density was high than when adult perch density was low.

    3. Both the individual niche breadth (if weighed for resource encounter) and the population niche breadth were highest when adult population density was high and, consequently, individual specialization was highest at high adult perch densities.

    4. When adult perch density was low, the abundances of benthic invertebrate and YOY perch were high and dominated the diet of adult perch, whereas the density of zoo-plankton was low due to predation from YOY perch. At high perch densities, benthic invertebrate abundance was lower and zooplankton level was higher and some perch switched to feed on zooplankton.

    5. Our results show that individual specialization may fluctuate with population density through feedback mechanisms via resource levels. Such fluctuations may have profound implications on the evolution of resource polymorphisms.

  • 1287. Svanbäck, Richard
    et al.
    Rydberg, Cecilia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Leonardsson, Kjell
    Englund, Göran
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Diet specialization in a fluctuating population of Saduria entomon: a consequence of resource or forager densities?2011Inngår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 120, nr 6, s. 848-854Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Intraspecific competition has been shown to favor diet specialization among individuals. However, the question whether the competition takes the form of interference or exploitative in driving diet specialization has never been investigated. We investigated individual diet specialization in the isopod Saduria entomon, in relation to forager and resource biomasses in a system that exhibits predator–prey fluctuations in density. We found that individual diet specialization was only affected by the biomass of their preferred prey (Monoporeia affinis) and not by Saduria biomass; diet specialization was higher when Monoporeia biomass was low compared to when there were high Monoporeia biomass. Population diet breadth increased at low Monoporeia biomass whereas individual diet breadths were marginally affected by Monoporeia biomass. Overall, this led to the increase in diet specialization at low Monoporeia biomass. This study shows that predator–prey dynamics might influence diet specialization in the predator and that resource biomass, not forager biomass might be important for individual diet specialization.

  • 1288. Szefer, P
    et al.
    Glasby, G P
    Geldon, J
    Renner, R M
    Björn, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Snell, James
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Frech, Wolfgang
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Warzocha, J
    Heavy-metal pollution of sediments from the Polish exclusive economic zone, southern Baltic Sea2009Inngår i: Environmental Geology, ISSN 0943-0105, E-ISSN 1432-0495, Vol. 57, nr 4, s. 847-862Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Analysis of 59 surface sediment samples from the Polish exclusive economic zone (EEZ) shows that Szczecin Lagoon sediments are the most polluted by heavy metals and that the degree of heavy-metal pollution decreases substantially on passing from the Szczecin Lagoon to the Pomeranian Bay and the inner shelf area and then on passing to the Bornholm Deep and Słupsk Furrow. Heavy-metal pollution in the sediments of the western part of the Polish EEZ therefore appears to follow the dispersion of the Oder River. Fluffy material from the Oder estuary appears to be the main source of heavy metals in the muddy sediments of the Bornholm Deep. The formation of sulphides is therefore not the principal factor controlling the enrichment of heavy metals in the sediments of this anoxic basin, although it may be responsible for the uptake of Mo, Sb and As. Two main factors control the distribution of the rare earth elements (REE) in sediments of the Polish EEZ: the input of Fe-organic colloids from rivers and the presence of detrital material in the sediments.

  • 1289.
    Södergren, Sam
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten.
    Ecological effects of heavy metal discharge in a salmon river1974Doktoravhandling, monografi (Annet vitenskapelig)
  • 1290.
    Söderström, Gunilla
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    On the combustion and photolytic degradation products of some brominated flame retardants2003Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Many modern products, especially electronic goods, are protected by brominated flame retardants (BFR). Some of the most common flame retardants are polybrominated diphenylethers (PBDE), tetrabromobisphenol-A (TBBP-A) and hexabromocyclododecane (HBCD). These compounds have been found in environmental samples and shown to have physiological effects on experimental animals. This thesis considers end-of-life aspects of brominated flame retardants. When spread in the environment, these compounds may be degraded into other forms. For example, if sludge contaminated with PBDE is used as an agricultural fertilizer, the PBDE could be degraded by sunlight to species of PBDE with lower degree of bromination and, to some extent, also form polybrominated dibenzofurans (PBDF). In addition, PBDF and polybrominated dibenzo-p-dioxins (PBDD) are formed during combustion of brominated flame retardants. When waste products with brominated flame retardants are co-combusted with household waste or other chlorinated fuel, polybrominated- chlorinated dibenzo-p-dioxins (PBCDD) and polybrominated- chlorinated dibenzofurans (PBCDF)will be formed. The bromin/chlorine composition of dioxins and furans is dependent on the bromine/chlorine ratio in the fuel, but the types of brominated flame retardants that are being combusted is less important. In the studies reported here, bromine levels higher than "normal" for household waste has been used. The results show that there is a pronounced increase in total dioxin levels in fluegas when when bromine is present, implying that waste containing brominated flame retardants should only be incinerated at combustion plants with effecient air pollution control devices.

  • 1291.
    Söderström, Gunilla
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Marklund, Stellan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Formation of PBCDD and PBCDF during flue gas cooling2004Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 38, nr 3, s. 825-830Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The presence of bromine and chlorine in combustion, particularly in waste combustion, results in the formation of PBCDD and PBCDF. Formation pathways of PCDD/F are not fully understood, although much is known about them, and they are currently being further investigated. PBCDD/F is likely to be formed in reactions similar to those leading to PCDD/F, but the processes involved have been less intensively studied. In this study a fuel with bromine and chlorine in equal molar amounts was combusted in a pilot-scale fluid bed reactor and the cooling flue gas was sampled at 800, 350, and 250 C. Analysis revealed that levels of PBCDD and PBCDF increased between all sampling ports. The chlorine/bromine ratio also increased with reductions in temperature and increases in residence time for both PBCDD and PBCDF. However, the formation of PBCDD and PBCDF seems to follow different routes with respect to the level and pattern of halogenation.

  • 1292.
    Söderström, Hanna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in air2004Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Air pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. However, active high volume samplers (HiVols) require a power supply, maintenance and specialist operators, and the equipment is often expensive. Thus, there is a need to develop new, less complicated sampling techniques that can increase the monitoring frequency, the geographical distribution of the measurements, and the number of sites used in air monitoring programs. In the work underlying this thesis, the use of semipermeable membrane devices (SPMDs) as tools for monitoring gas phase concentrations of nonpolar aromatic compound was evaluated using the compound classes polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs (alkyl-PAHs) and nitrated PAHs (nitro-PAHs) as test compounds.

    High wind-speeds increased the uptake and release in SPMDs of PAHs and PCBs with log KOA values > 7.9, demonstrating that the uptake of most nonpolar aromatic compounds is controlled by the boundary layer at the membrane-air interface. The use of a metal umbrella to shelter the SPMDs decreased the uptake of PAHs and PCBs by 38 and 55 percent, respectively, at high wind/turbulence, and thus reduced the wind effect. Further, the use of performance reference compounds (PRCs) to assess the site effect of wind on the uptake in SPMDs reduced the between-site differences to less than 50 percent from as much as three times differences in uptake of PCBs and PAHs. However, analytical interferences reduced the precision of some PRCs, showing the importance of using robust analytical quality control.

    SPMDs were shown to be efficient samplers of gas phase nonpolar aromatic compounds, and were able to determine local, continental and indoor spatial distributions of PAHs, alkyl- PAHs and nitro-PAHs. In addition, the use of the SPMDs, which do not require electricity, made sampling possible at remote/rural areas where the infrastructure was limited. SPMDs were also used to determine the source of PAH pollution, and different approaches were discussed. Finally, SPMDs were used to estimate the importance of the gas phase exposure route to the uptake of PAHs in plants. The results demonstrate that SPMDs have several advantages compared with HiVols, including integrative capacity over long times, reduced costs, and no need of special operators, maintenance or power supply for sampling. However, calibration data of SPMDs in air are limited, and spatial differences are often only semi-quantitatively determined by comparing amounts and profiles in the SPMDs, which have limited their use in air monitoring programs. In future work, it is therefore important that SPMDs are properly sheltered, PRCs are used in the sampling protocols, and that calibrated sampling rate data, or the SPMD-air partition data, of specific compounds are further developed to make determination of time weighted average (TWA) concentrations possible.

  • 1293. Taj, Tahir
    et al.
    Malmqvist, Ebba
    Stroh, Emilie
    Oudin Åström, Daniel
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin. Center for Primary Health Care Research, Department of Clinical Science, Malmö, Lund University, Malmö, Sweden.
    Jakobsson, Kristina
    Oudin, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin. Department of Occupational and Environmental Medicine, Lund University, Lund, Sweden.
    Short-Term Associations between Air Pollution Concentrations and Respiratory Health-Comparing Primary Health Care Visits, Hospital Admissions, and Emergency Department Visits in a Multi-Municipality Study2017Inngår i: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 14, nr 6, artikkel-id 587Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Acute effects of air pollution on respiratory health have traditionally been investigated with data on inpatient admissions, emergency room visits, and mortality. In this study, we aim to describe the total acute effects of air pollution on health care use for respiratory symptoms (ICD10-J00-J99). This will be done by investigating primary health care (PHC) visits, inpatient admissions, and emergency room visits together in five municipalities in southern Sweden, using a case-crossover design. Between 2005 and 2010, there were 81,019 visits to primary health care, 38,217 emergency room visits, and 25,271 inpatient admissions for respiratory symptoms in the study area. There was a 1.85% increase (95% CI: 0.52 to 3.20) in the number of primary health care visits associated with a 10 mu g/m(3) increase in nitrogen dioxide (NO2) levels in Malmo, but not in the other municipalities. Air pollution levels were generally not associated with emergency room visits or inpatient admissions, with one exception (in Helsingborg there was a 2.52% increase in emergency room visits for respiratory symptoms associated with a 10 mu g/m(3) increase in PM10). In conclusion, the results give weak support for short-term effects of air pollution on health care use associated with respiratory health symptoms in the study area.

  • 1294.
    Talyzina, Nina M
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ingvarsson, Pär K
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Zhu, J
    Wai, Sun N
    Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten).
    Andersson, Agneta
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Molecular diversification in the quorum-sensing system of vibrio cholerae: role of natural selection in the emergence of pandemic strains2009Inngår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 75, s. 3808-3812Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two haplotypes of the Vibrio cholerae quorum-sensing system regulator hapR are described: hapR1, common among nonpandemic, non-O1, non-O139 strains, and hapR2, associated with pandemic O1 and O139 and epidemic O37 V. cholerae strains. The hapR2 has evolved under strong natural selection, implying that its fixation was influenced by conditions that led to cholera pandemics.

  • 1295. Tang, Jing
    et al.
    Yurova, Alla Y.
    Schurgers, Guy
    Miller, Paul A.
    Olin, Stefan
    Smith, Benjamin
    Siewert, Matthias B.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Physical Geography, Stockholm University, Sweden.
    Olefeldt, David
    Pilesjö, Petter
    Poska, Anneli
    Drivers of dissolved organic carbon export in a subarctic catchment: Importance of microbial decomposition, sorption-desorption, peatland and lateral flow2018Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 622, s. 260-274Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tundra soils account for 50% of global stocks of soil organic carbon (SOC), and it is expected that the amplified climate warming in high latitude could cause loss of this SOC through decomposition. Decomposed SOC could become hydrologically accessible, which increase downstream dissolved organic carbon (DOC) export and subsequent carbon release to the atmosphere, constituting a positive feedback to climate warming. However, DOC export is often neglected in ecosystem models. In this paper, we incorporate processes related to DOC production, mineralization, diffusion, sorption-desorption, and leaching into a customized arctic version of the dynamic ecosystem model LPJ-GUESS in order to mechanistically model catchment DOC export, and to link this flux to other ecosystem processes. The extended LPJ-GUESS is compared to observed DOC export at Stordalen catchment in northern Sweden. Vegetation communities include flood-tolerant graminoids (Eriophorum) and Sphagnum moss, birch forest and dwarf shrub communities. The processes, sorption-desorption and microbial decomposition (DOC production and mineralization) are found to contribute most to the variance in DOC export based on a detailed variance-based Sobol sensitivity analysis (SA) at grid cell-level. Catchment-level SA shows that the highest mean DOC exports come from the Eriophorum peatland (fen). A comparison with observations shows that the model captures the seasonality of DOC fluxes. Two catchment simulations, one without water lateral routing and one without peatland processes, were compared with the catchment simulations with all processes. The comparison showed that the current implementation of catchment lateral flow and peatland processes in LPJ-GUESS are essential to capture catchment-level DOC dynamics and indicate the model is at an appropriate level of complexity to represent the main mechanism of DOC dynamics in soils. The extended model provides a new tool to investigate potential interactions among climate change, vegetation dynamics, soil hydrology and DOC dynamics at both stand-alone to catchment scales. 

  • 1296.
    Tarberg, Martin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Utsläpp av växthusgaser under islossning i små boreala sjöar2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Freshwater ecosystems have long been neglected as an important part of the global carbon cycle. However, research shows that most of the world’s lakes are net-heterotrophic and consequently emitters of greenhouse gases to the atmosphere. In many boreal and north-temperate lakes, most of the yearly emissions usually occur in spring, shortly after ice-thaw. The aim of this study was to quantify the flux of carbon dioxide (CO2) and methane (CH4) in three boreal lakes, during this annual event. In order to do this, water samples were collected before and after ice-thaw, and the flux was estimated as the difference in mass of carbon between the two sampling occasions. The results showed that the lakes had accumulated high amounts of carbon over the winter, with higher concentrations generally at higher depths. The fluxes during ice-thaw ranged from 234–380 (mean: 302) and -1.15–15.12 (mean: 8.64) mmol m-2 y-1 for CO2 and CH4, respectively. Given their small sizes, the lakes emitted less carbon, per unit area, than expected. This was assumed to be due to the lakes’ rather isolated locations and since the heating of the water rapidly caused them to become highly stratified, thus preventing the wind from releasing deeper stored carbon. Presumably, this holds true for other similar boreal lakes as well, which suggests that attention – in such ecosystems – also needs to be brought to other mixing periods.

  • 1297. Tawatsupa, Benjawan
    et al.
    Dear, Keith
    Kjellström, Tord
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Epidemiologi och global hälsa.
    Sleigh, Adrian
    The association between temperature and mortality in tropical middle income Thailand from 1999 to 20082014Inngår i: International journal of biometeorology, ISSN 0020-7128, E-ISSN 1432-1254, Vol. 58, nr 2, s. 203-215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have investigated the association between tropical weather condition and age-sex adjusted death rates (ADR) in Thailand over a 10-year period from 1999 to 2008. Population, mortality, weather and air pollution data were obtained from four national databases. Alternating multivariable fractional polynomial (MFP) regression and stepwise multivariable linear regression analysis were used to sequentially build models of the associations between temperature variable and deaths, adjusted for the effects and interactions of age, sex, weather (6 variables), and air pollution (10 variables). The associations are explored and compared among three seasons (cold, hot and wet months) and four weather zones of Thailand (the North, Northeast, Central, and South regions). We found statistically significant associations between temperature and mortality in Thailand. The maximum temperature is the most important variable in predicting mortality. Overall, the association is nonlinear U-shape and 31 A degrees C is the minimum-mortality temperature in Thailand. The death rates increase when maximum temperature increase with the highest rates in the North and Central during hot months. The final equation used in this study allowed estimation of the impact of a 4 A degrees C increase in temperature as projected for Thailand by 2100; this analysis revealed that the heat-related deaths will increase more than the cold-related deaths avoided in the hot and wet months, and overall the net increase in expected mortality by region ranges from 5 to 13 % unless preventive measures were adopted. Overall, these results are useful for health impact assessment for the present situation and future public health implication of global climate change for tropical Thailand.

  • 1298.
    te Beest, Mariska
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Community and Conservation Ecology Group, University of Groningen, Groningen, The Netherlands.
    Elschot, Kelly
    Olff, Han
    Etienne, Rampal S.
    Invasion success in a marginal habitat: an experimental test of competitive ability and drought tolerance in Chromolaena odorata2013Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 8, artikkel-id e68274Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climatic niche models based on native-range climatic data accurately predict invasive-range distributions in the majority of species. However, these models often do not account for ecological and evolutionary processes, which limit the ability to predict future range expansion. This might be particularly problematic in the case of invaders that occupy environments that would be considered marginal relative to the climatic niche in the native range of the species. Here, we assess the potential for future range expansion in the shrub Chromolaena odorata that is currently invading mesic savannas (>650 mm MAP) in South Africa that are colder and drier than most habitats in its native range. In a greenhouse experiment we tested whether its current distribution in South Africa can be explained by increased competitive ability and/or differentiation in drought tolerance relative to the native population. We compared aboveground biomass, biomass allocation, water use efficiency and relative yields of native and invasive C. odorata and the resident grass Panicum maximum in wet and dry conditions. Surprisingly, we found little differentiation between ranges. Invasive C. odorata showed no increased competitive ability or superior drought tolerance compared to native C. odorata. Moreover we found that P. maximum was a better competitor than either native or invasive C. odorata. These results imply that C. odorata is unlikely to expand its future range towards more extreme, drier, habitats beyond the limits of its current climatic niche and that the species' invasiveness most likely depends on superior light interception when temporarily released from competition by disturbance. Our study highlights the fact that species can successfully invade habitats that are at the extreme end of their ranges and thereby contributes towards a better understanding of range expansion during species invasions.

  • 1299. Tennberg, Monica
    et al.
    Dale, Brigt
    Klyuchnikova, Elena
    Löf, Annette
    Umeå universitet, Humanistiska fakulteten, Centrum för samisk forskning (CeSam).
    Masloboev, Vladimir
    Scheepstra, Annette
    Kietaevaeinen, Asta
    Naskali, Päivi
    Rautio, Arja
    Local and regional perspectives on adaptation2017Inngår i: Adaptation actions for a changing Arctic: perspectives from the Barents area / [ed] Carolyn Symon, Oslo: Arctic Monitoring and Assessment Programme (AMAP) , 2017, s. 47-58Kapittel i bok, del av antologi (Fagfellevurdert)
  • 1300.
    Tesfalidet, Solomon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Screening of organotin compounds in the Swedish environment: SNV contract: 219 0102 : March 20042004Rapport (Annet vitenskapelig)
    Abstract [en]

    The ecotoxicological effects of organotin compounds (OTC), mainly tributyltin (TBT) and triphe-nyltin (TPhT) but also their di- and monosubstituted degradation products are well documented. Nowadays, the release of TBT from antifouling paints is recognized worldwide as being one of the main contamination problems for the marine environment, and the use of TBT-based antifouling paints is almost everywhere restricted by law. In order to evaluate the environmental distribution and fate of these compounds, and to control the effectiveness of these legal provisions, many analy-tical methods have been developed among which gas chromatography coupled to inductively coup-led plasma mass spectrometry (GC-ICP-MS) is the most powerful. Previous studies in the Swedishenvironment have shown the presence of considerable amounts of butyltins in mussel and sedimentsamples. In the present study, screening of both butyltins and phenyltins in the Swedish environment is per-formed using GC-ICP-MS. A method for species specific isotope dilution, (SSID-GC-ICP-MS) wasdeveloped using isotopicaly labelled butyl- and phenyltins, synthesized in our laboratory from iso-topically enriched metallic 116Sn and 124Sn respectively. Biological samples (clupea harengus, mytilus edulis, salmo salmar, and nassarius reticulatus), sediments, sewage sludge, water samplesfrom purification plants, and harbours were collected from different parts of Sweden and analysed. Generally, the concentrations of OTCs for most samples were found to be lower compared to theamounts reported in 1987. The concentration of TBT, for example, is now 0.1-0.6 ng Sn/L compared to the 260-410 ng Sn/L reported in 1987 for the water samples from Fiskebäckskilsvik. The decrease in OTC concentration was also noticeable for the mussel (mytilus edulis) samples taken from the same area. The concentration of TBT in the mussel samples was found to bebetween 17-364 ng Sn/g compared to the concentrations 1000-18000 ng Sn/g reported in 1987. Considerable amounts of OTCs were found in the monthly sludge from the water purification plant in Loudden (Stockholm) where monobutyltin (MBT), dibutyltin (DBT), and TBT concentrations were found to be 39, 692, and 32 ng/g respectively. The results from the determination of OTCs in the sediment samples from Gålö, Karlsudd revealed that the sediment layers between 1-3 cm and 39-50 cm had the highest concentrations. A literature study over relevant topics concerning OTC was performed. More than 140 references organized by the filing programme (Idealist) are presented in a separate file.

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