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  • 1. Almeida, Nazare da Silva
    et al.
    Sawakuchi, Henrique Oliveira
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Thematic Studies–Environmental Change, Linköping University, Hus Temahuset, Campus Valla, 581 83 Linköping, Sweden.
    Teixeira, C.A.S.
    Bertassoli Jr., D.J.
    Furukawa, L.Y.
    Pelissari, M.
    Sawakuchi, A.O.
    Incubation experiments to constrain the production of methane and carbon dioxide in organic-rich shales of the Permian Irati Formation, Parana Basin2020Ingår i: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 112, artikel-id 104039Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Permian Irati Formation in Brazil hosts organic-rich shales and heavy hydrocarbons suitable for biogenic production of methane (CH4) and carbon dioxide (CO2). In this study, shale samples from the irati Formation were used in laboratory incubation experiments performed under different temperatures (22 degrees C, 50 degrees C, 70 degrees C and 80 degrees C) to evaluate the generation of CH4 and CO2 under thermal conditions compatible with biodegradation in shallow gas systems (< 80 degrees C). Despite our laboratory experiments do not represent natural subsurface temperature conditions, it is observed that the concentrations of CH4 and CO2 increase when shale samples are incubated under temperature higher than 22 degrees C. Samples incubated at 80 degrees C presented a maximum CH4 yield of 2.45 ml/t.d (milliliter per ton of shale per day) compared to 0,49 ml/t.d at 22 degrees C, 1.75 ml/t.d at 50 degrees C and 2.09 ml/t.d at 70 degrees C. The same trend of increasing production rates with higher temperatures was observed for CO2, with maximum potential production observed under a laboratory temperature of 80 degrees C, reaching 23.47 ml/t.d. Stable carbon isotopes (delta C-13) on CH4 and CO2 suggest a mixture of thermogenic and secondary microbial gas. However, the measured CH4 and CO2 can be generated through methanogenic degradation of heavy hydrocarbons present in the studied shales, difficulting the use of carbon isotope composition to discriminate between biogenic and thermogenic gases. The studied shale samples showed significant differences in CH4 and CO2 production rates, which are possibly related to the major elements composition of the mineral matrix. Higher CH4 and CO2 production rates occurred in samples with higher amount of sulfur. Besides sulfur, we highlight that others soluble elements in the mineral matrix, such as Ca and Mg, can play an important role for the generation of biogenic CH4 and CO2. The present work intends to alert for the importance of thermal conditions as well as the geochemical composition of the mineral matrix to build conceptual models about shallow gas systems, acting on organic-rich shales in sedimentary basins.

  • 2.
    Backman, Fredrick
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier.
    Från föhn till feu!: Esrange och den norrländska rymdverksamhetens tillkomsthistoria från sekelskiftet 1900 till 19662010Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This essay is about the origin, planning and establishment of the European Space Research Organisation's (ESRO) sounding rocket base Esrange outside Kiruna in Northern Sweden. Three main questions are examined. First I show there were not just scientific and technical but also political, economical as well as military reasons to build a European rocket base. Second, I scrutinize the reasons to choose Northern Sweden as the location for the rocket base. As it turns out, the main reasons were the favourable location of Northern Sweden within the aurora oval zone, the proximity of the Kiruna Geophysical Observatory, and the possibility to use a large, although not quite uninhabited, area where the launched rockets could crash. Finally, I examine the difficulty of talking about boundaries of various kinds, such as temporal, spatial and functional. The essay also provides a discussion on possible ways to continue research on this topic.

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  • 3.
    Becher, Marina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Cryogenic soil processes in a changing climate2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    A considerable part of the global pool of terrestrial carbon is stored in high latitude soils. In these soils, repeated cycles of freezing and thawing creates soil motion (cryoturbation) that in combination with other cryogenic disturbance processes may play a profound role in controlling the carbon balance of the arctic soil. Conditions for cryogenic soil processes are predicted to dramatically change in response to the ongoing climate warming, but little is known how these changes may affect the ability of arctic soils to accumulate carbon. In this thesis, I utilize a patterned ground system, referred to as non-sorted circles, as experimental units and quantify how cryogenic soil processes affect plant communities and carbon fluxes in arctic soils. I show that the cryoturbation has been an important mechanism for transporting carbon downwards in the studied soil over the last millennia. Interestingly, burial of organic material by cryoturbation appears to have mainly occurred during bioclimatic events occurring around A.D. 900-1250 and A.D. 1650-1950 as indicated by inferred 14C ages. Using a novel photogrammetric approach, I estimate that about 0.2-0.8 % of the carbon pool is annually subjected to a net downward transport induced by the physical motion of soil. Even though this flux seems small, it suggests that cryoturbation is an important transporter of carbon over centennial and millennial timescales and contributes to translocate organic matter to deeper soil layers where respiration proceeds at slow rates. Cryogenic processes not only affect the trajectories of the soil carbon, but also generate plant community changes in both species composition and abundance, as indicated by a conducted plant survey on non-sorted circles subjected to variable differential frost heave during the winter. Here, disturbance-tolerant plant species, such as Carex capillaris and Tofieldia pusilla, seem to be favoured by disturbance generated by the differential heave. Comparison with findings from a previous plant survey on the site conducted in the 1980s suggest that the warmer temperatures during the last decades have resulted in decreased differential heave in the studied non-sorted circles. I argue that this change in cryogenic activity has increased abundance of plants present in the 1980s. The fact that the activity and function of the non-sorted circles in Abisko are undergoing changes is further supported by their contemporary carbon dioxide (CO2) fluxes. Here, my measurements of CO2 fluxes suggest that all studied non-sorted circles act as net CO2 sources and thus that the carbon balance of the soils are in a transition state. My results highlight the complex but important relationship between cryogenic soil processes and the carbon balance of arctic soils.

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  • 4.
    Becher, Marina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Börlin, Niclas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Measuring soil motion with terrestrial close range photogrammetry in periglacial environments2014Ingår i: EUCOP 4: Book of Abstracts / [ed] Gonçalo Vieira, Pedro Pina, Carla Mora and António Correia, University of Lisbon and the University of Évora , 2014, s. 351-351Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Cryoturbation plays an important role in the carbon cycle as it redistributes carbon deeper down in the soil where the cold temperature prevents microbial decomposition. This contribution is also included in recent models describing the long-term build up of carbon stocks in artic soils. Soil motion rate in cryoturbated soils is sparsely studied. This is because the internal factors maintaining cryoturbation will be affected by any excavation, making it impossible to remove soil samples or install pegs without changing the structure of the soil. So far, mainly the motion of soil surface markers on patterned ground has been used to infer lateral soil motion rates. However, such methods constrain the investigated area to a predetermined distribution of surface markers that may result in a loss of information regarding soil motion in other parts of the patterned ground surface.

    We present a novel method based on terrestrial close range (<5m) photogrammetry to calculate lateral and vertical soil motion across entire small-scale periglacial features, such as non-sorted circles (frost boils). Images were acquired by a 5-camera calibrated rig from at least 8 directions around a non-sorted circle. During acquisition, the rig was carried by one person in a backpack-like portable camera support system. Natural feature points were detected by SIFT and matched between images using the known epipolar geometry of the calibrated rig. The 3D coordinates of points matched between at least 3 images were calculated to create a point cloud of the surface of interest. The procedure was repeated during two consecutive years to be able to measure any net displacement of soil and calculate rates of soil motion. The technique was also applied to a peat palsa where multiple exposures where acquired of selected areas.

    The method has the potential to quantify areas of disturbance and estimate lateral and vertical soil motion in non-sorted circles. Furthermore, it should be possible to quantify peat erosion and rates of desiccation crack formations in peat palsas. This tool could provide new information about cryoturbation rates that could improve existing soil carbon models and increase our understanding about how soil carbon stocks will respond to climate change.

  • 5.
    Becher, Marina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Olofsson, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Berglund, Louise
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Decreased cryogenic disturbance: one of the potential mechanisms behind the vegetation change in the Arctic2018Ingår i: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 41, nr 1, s. 101-110Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    During the last few decades, the Arctic has experienced large-scale vegetation changes. Understanding the mechanisms behind this vegetation change is crucial for our ability to predict future changes. This study tested the hypothesis that decreased cryogenic disturbances cause vegetation change in patterned ground study fields (non-sorted circles) in Abisko, Sweden during the last few decades. The hypothesis was tested by surveying the composition of plant communities across a gradient in cryogenic disturbance and by reinvestigating plant communities previously surveyed in the 1980s to scrutinise how these communities changed in response to reduced cryogenic disturbance. Whereas the historical changes in species occurrence associated with decreased cryogenic disturbances were relatively consistent with the changes along the contemporary gradient of cryogenic disturbances, the species abundance revealed important transient changes highly dependent on the initial plant community composition. Our results suggest that altered cryogenic disturbances cause temporal changes in vegetation dynamics, but the net effects on vegetation communities depend on the composition of initial plant species.

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  • 6.
    Bigler, Christian
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Gälman, Veronika
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Renberg, Ingemar
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Numerical simulations suggest that counting sums and taxonomic resolution of diatom analyses to determine IPS pollution and ACID acidity indices can be reduced2010Ingår i: Journal of Applied Phycology, ISSN 0921-8971, E-ISSN 1573-5176, Vol. 22, nr 5, s. 541-548Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Implementation of the European Union Water Framework Directive and associated national guidelines has emphasized the value of using biota, such as epilithic diatoms in streams, as indicators of water quality. However, guidelines for evaluating diatom samples have been established without explicitly evaluating their statistical robustness. We used epilithic diatom samples from 73 streams in northern Sweden and simulated the effects of variations in the counting sum size and taxonomic resolution of classifications for two indices indicating pollution (Indice de Polluo-sensibilité Spécifique, IPS) and acidity (acidity index for diatoms, ACID). Instead of the stipulated 400, we found that a count sum of 40 diatom valves for 50 streams, and 80 valves for 60 streams, would have been sufficient to obtain the same IPS index classification. The ACID index is more sensitive to count sum reductions, since the same classification would only have been obtained for 12 streams with 40 counted diatom valves or 24 streams with a count of 80 valves. Excluding rare taxa had negligible effects on the IPS and ACID indices. Excluding taxa occurring with less than 1.0% frequency affected the IPS classification of only one stream, and excluding taxa with less than 2.5% and 5.0% frequencies affected those of just one and no streams, respectively. The ACID index was affected for none, five, and 12 streams, respectively. At least in relatively unpolluted regions such as northern Sweden, our simulations suggest that a simplified methodological approach with site-specific counting sum sizes and reduced taxonomical resolution could be adopted, taking into account the way sites are classified in relation to established class boundaries. The simplified method is a step forward in improving the cost efficiency for stream monitoring, as costs of diatom analysis to obtain identical IPS and ACID classifications of our streams could be reduced considerably. Before the simplified method can be widely adopted, further simulations including regions with a higher proportion of polluted streams are required.

  • 7.
    Bindler, Richard
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Yu, Ruilian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. College of Chemical Engineering, Huaqiao University, Xiamen, Fujian 361021, P.R. China.
    Hansson, Sophia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Classen, Neele
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Karlsson, Jon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Mining, Metallurgy and the Historical Origin of Mercury Pollution in Lakes and Watercourses in Central Sweden2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 15, s. 7984-7991Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In Central Sweden an estimated 80% of the lakes contain fish exceeding health guidelines for mercury. This area overlaps extensively with the Bergslagen ore region, where intensive mining of iron ores and massive sulfide ores occurred over the past millennium. Although only a few mines still operate today, thousands of mineral occurrences and mining sites are documented in the region. Here, we present data on long-term mercury pollution in 16 sediment records from 15 lakes, which indicate that direct release of mercury to lakes and watercourses was already significant prior to industrialization (<AD 1800). Thirteen of our lakes show increases in mercury from 3-fold-equivalent to the enrichment factor in many remote lakes today-to as much as 60-fold already during the period AD 1500-1800, with the highest values in the three lakes most closely connected to major mines. Although the timing and magnitude of the historical increases in mercury are heterogeneous among lakes, the data provide unambiguous evidence for an incidental release of mercury along with other mining metals to lakes and watercourses, which suggests that the present-day problem of elevated mercury concentrations in the Bergslagen region can trace its roots back to historical mining.

  • 8.
    Buckland, Paul C.
    et al.
    University of Sheffield, UK.
    Panagiotakopulu, Eva
    Edinburgh University, Scotland.
    Buckland, Philip I.
    Umeå universitet, Humanistiska fakulteten, Arkeologi och samiska studier, Miljöarkeologiska laboratoriet.
    Perdikaris, Sophia
    Skidmore, Peter
    Insect faunas from Medieval Langenes in Arctic Norway2006Ingår i: Proceedings from the VIII Nordic Conference on the Application of Scientific Methods In Archaeology, Umeå, Sweden, 2001 / [ed] Engelmark, Roger; Linderholm, Johan, Umeå University , 2006, s. 17-32Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cultural sediments containing significant amounts of fish bone at Langenesværet, Vesterålen, Northern Norway provide an opportunity to characterise activity during and prior to the establishment of a late medieval commercial fishing station (fiskevaer). Radiometric and AMS dating techniques are used to establish a chronology for the deposits, while activities associated with the sediments are characterised fossil insect faunas. The results highlight a series of problems with the dating of the heavily disturbed organic deposits of many archaeological sites, and the need for greater care in sample selection and interpretation.

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  • 9.
    Buckland, Philip I.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet. Umeå universitet, Humanistiska fakulteten, Humlab.
    The Bugs Coleopteran Ecology Package (BugsCEP) database: 1000 sites and half a million fossils later2014Ingår i: Quaternary International, ISSN 1040-6182, E-ISSN 1873-4553, Vol. 341, s. 272-282Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Bugs database project started in the late 1980s as what would now be considered a relatively simple system, albeit advanced for its time, linking fossil beetle species lists to modern habitat and distribution information. Since then, Bugs has grown into a complex database of fossils records, habitat and distribution data, dating and climate reference data wrapped into an advanced software analysis package. At the time of writing, the database contains raw data and metadata for 1124 sites, and Russell Coope directly contributed to the analysis of over 154 (14%) of them, some 98790 identifications published in 231 publications. Such quantifications are infeasible without databases, and the analytical power of combining a database of modern and fossil insects with analysis tools is potentially immense for numerous areas of science ranging from conservation to Quaternary geology.

    BugsCEP, The Bugs Coleopteran Ecology Package, is the latest incarnation of the Bugs database project. Released in 2007, the database is continually added too and is available for free download from http://www.bugscep.com. The software tools include quantitative habitat reconstruction and visualisation, correlation matrices, MCR climate reconstruction, searching by habitat and retrieving, among other things, a list of taxa known from the selected habitat types. It also provides a system for entering, storing and managing palaeoentomological data as well as a number of expert system like reporting facilities.

    Work is underway to create an online version of BugsCEP, implemented through the Strategic Environmental Archaeology Database (SEAD) project (http://www.sead.se). The aim is to provide more direct access to the latest data, a community orientated updating system, and integration with other proxy data. Eventually, the tools available in the offline BugsCEP will be duplicated and Bugs will be entirely in the web.

    This paper summarises aspects of the current scope, capabilities and applications of the BugsCEP database and software, with special reference to and quantifications of the contributions of Russell Coope to the field of palaeoentomology as represented in the database. The paper also serves to illustrate the potential for the use of BugsCEP in biographical studies, and discusses some of the issues relating to the use of large scale sources of quantitative data.

    All datasets used in this article are available through the current version of BugsCEP available at http://www.bugscep.com.

  • 10.
    Buckland, Philip I.
    et al.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Buckland, Paul C.
    Den Bank Close, Sheffield, United Kingdom.
    Pitfall trapping at Gården Under Sandet (GUS) 1995, Western Greenland2023Ingår i: Norwegian Journal of Entomology, ISSN 1501-8415, E-ISSN 1894-0692, Vol. 70, nr 2, s. 158-169Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During archaeological excavations on the site of the Norse farm at Gården under Sandet (GUS), in Ameralik Fjord, south-west Greenland, the opportunity was taken to sample the modern ground-living insect fauna by pitfall trapping from a range of natural habitats for comparison with fossil assemblages from the medieval farm and its midden. Two species, the predatory bug Nabis flavomarginatus Scholtz, 1847 and small ladybird Nephus redtenbacheri Mulsant, 1846 are recorded for the first time in this part of Greenland, although there are earlier records from the sediments associated with medieval farms in the region and both have been regarded as Norse introductions. The minute staphylinid Mycetoporus nigrans Mäklin, 1853, added to the Greenland list from this material by Peter Hammond (in Buckland et al. 1998), was found to be common in most natural habitats around GUS. Grids of eight traps, four at ground level and four on posts, were set out in six localities defined by their vegetational characteristics and emptied three times over the month-long sampling period. The cicadellid Psammotettix lividellus (Zetterstedt, 1840) appeared in all ground traps being particularly abundant on the dwarf birch and sedge dominated floodplain, to which the polyphagous mirid bug Chlamydatus pullus (Reuter, 1870) appears confined.

  • 11.
    Buckland, Philip I.
    et al.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier.
    Dell'Unto, Nicolo
    Lund University.
    Pálsson, Gísli
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier.
    To tree, or not to tree? On the Empirical Basis for Having Past Landscapes to Experience2018Ingår i: Digital Humanities Quarterly, E-ISSN 1938-4122, Vol. 12, nr 3Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    This article provides an overview of some of the complex issues involved in reconstructing and visualizing past landscapes. It discusses the importance of empirical data and introduces some of the terminology necessary for understanding methods which are often considered more in the domain of the natural sciences than humanities. Current methods and practices are put in the context of environmental archaeology, archaeological theory and heritage management as well as related, briefly, to the broader context of archaeological theory, practice and research data infrastructure. Finally, some examples and pointers for the future are given in the hope that the article may provide a point of reference for those looking to gain an entry point into the study of past landscapes, and understand their relevance in archaeological visualisation.

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  • 12.
    Buckland, Philip I.
    et al.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Eriksson, Erik J.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Palm, Fredrik
    Umeå universitet, Humanistiska fakulteten, Humlab.
    SEAD - The Strategic Environmental Archaeology Database: Progress Report Spring 20142014Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report provides an overview of the progress and results of the VR:KFI infrastructure projects 2007-7494 and (825-)2010-5976. It should be considered as a status report in an on-going long-term research infrastructure development project.

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    SEAD - Progress Report Spring 2014
  • 13.
    Buckland, Philip I.
    et al.
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Sjölander, Mattias
    Umeå universitet, Humanistiska fakulteten, Institutionen för idé- och samhällsstudier, Miljöarkeologiska laboratoriet.
    Eriksson, Erik J.
    ICT Services and System Development (ITS), Umeå University, Umeå, Sweden.
    Strategic Environmental Archaeology Database (SEAD)2018Ingår i: Encyclopedia of global archaeology / [ed] Smith, C., Cham: Springer, 2018, 2Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Environmental archaeology encompasses a wide range of scientific methods for analyzing the results of past human activities, environments, climates, and perhaps, most importantly, the relationships between these. Many of these methods are referred to as proxy analyses, denoting the illumination of the past as interpreted indirectly through the evidence of fossil organisms or properties. These lines of evidence, or proxy data sources, are assumed to reflect past conditions by way of their dependence on them. For example, a species of beetle may only survive within a specific climate range, and thus its presence in samples indicates this climate at the time of deposition; organic waste deposited around a farmstead will raise soil phosphate levels above those of the surrounding land; and the presence of cereal grains in postholes suggests their local cultivation or import, usage, or storage.

  • 14.
    Classen, Neele
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    1000 years of environmental changes in Falun, Sweden: Lake Sediment as source material2012Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this study was to get a better knowledge of the metal pollution and the mining

    history of the Falun area. It adds new information on the geochemistry of the lakes and the

    beginning of mining in the Falun region, together with the influence of early land use. The

    main focus is on three lakes Hagtjärnen, Stugutjärnen and Nästjärnen, which were previously

    dated and analyzed regarding acidification by Anna Ek. Additional supporting information is

    provided from records from 10 other lakes, which are located at distances between 0-27 km

    from the Falun Copper mine. Another specific focus is on the lake Tisken, which has been

    assumed over the past 50 years to represent faithful historical record of mining in the Falun

    area. In this study this lake record was dated and analyzed, too. The analyses of all the lakes

    included resulted in four significant phases of environmental change, indicating the start of

    agriculture and mining, the development of each sector, as well as the sharp increase in

    pollution in the modern time period. Phase I covers the time period A.D. 700-1000 and

    represents the time of the early beginning of land use and small scale mining activities. Phase

    II represents the time between A.D. 1200 to 1450, which is dominated by an ongoing

    development of mining and a sharp increase in metal concentrations and occurrence of

    cultivated plants and plants favored by disturbance from A.D. 1450 onwards. The third phase,

    representing the year A.D. 1540, clearly displays another period of sharp increases among the

    metal concentrations, which coincides with a peak in Cu production volumes. Phase IV

    covers the time period A.D. 1750-1900, referred to as Modern time, and features a clear

    increase in Pb pollution, which is linked to the introduction of tetra ethyl Pb in the 1970s.

    Other metals increase also, together with cultivated plants like cereals, indicating an ongoing

    expansion of mining and agriculture. The results also indicate that Cu was not emitted as far

    as other elements, like for example Pb, which led to great pollution only in the lakes close to

    the Falun mine.

    Another important finding is that the lake Tisken does not represent a continual historical

    record, because the sediment is not a chronological sequence and instead likely represents

    mostly a catastrophic input of debris of mixed age. The C-14 dating shows, that the sediment

    is mixed and disturbed in Tisken. As a consequence, the long-standing interpretation of

    Tisken’s sediment record as an archive for the historical start and late development of mining

    at the Falun copper mine is incorrect

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  • 15. Cormier, Marc-André
    et al.
    Werner, Roland A.
    Sauer, Peter E.
    Gröcke, Darren R.
    Leuenberger, Markus C.
    Wieloch, Thomas
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Schleucher, Jürgen
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Kahmen, Ansgar
    2H-fractionations during the biosynthesis of carbohydrates and lipids imprint a metabolic signal on the δ2H values of plant organic compounds2018Ingår i: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 218, nr 2, s. 479-491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hydrogen (H) isotope ratio (δ2H) analyses of plant organic compounds have been applied to assess ecohydrological processes in the environment despite a large part of the δ2H variability observed in plant compounds not being fully elucidated.

    We present a conceptual biochemical model based on empirical H isotope data that we generated in two complementary experiments that clarifies a large part of the unexplained variability in the δ2H values of plant organic compounds.

    The experiments demonstrate that information recorded in the δ2H values of plant organic compounds goes beyond hydrological signals and can also contain important information on the carbon and energy metabolism of plants. Our model explains where 2H‐fractionations occur in the biosynthesis of plant organic compounds and how these 2H‐fractionations are tightly coupled to a plant's carbon and energy metabolism. Our model also provides a mechanistic basis to introduce H isotopes in plant organic compounds as a new metabolic proxy for the carbon and energy metabolism of plants and ecosystems.

    Such a new metabolic proxy has the potential to be applied in a broad range of disciplines, including plant and ecosystem physiology, biogeochemistry and palaeoecology.

  • 16.
    Dahlqvist, Erica
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Undersökning av parametrar som kan öka mobiliteten av arsenik i grundvatten efter jordtvätt i Gudarp.2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    After soil washing in the former wood preservation industry, the concentration of As (arsenic) have increased in the groundwater. The purpose of this study was to investigate different parameters that could increase the mobility of As in the groundwater. The impact the soil wash has on the soil and it is effect on mobility will also be consider. This study will also show how As, Cu and Cr changes over time, however, the focus will be on As when the soil washing have been controlled by the As concentration. Soil and groundwater samples have been collected. Through filtration Fe (iron), Al (aluminium) and TOC (Total organic carbon) together with As have been analysed to determine a possible relation. Redox potential and As specification have also been analysed. As occur probably dissolved in the groundwater or together with DOC (Dissolved organic carbon). No link between colloids and complexes with Fe and Al together with As was found through filtration. Redox potential has no impact since the water was well oxygenated and As occurred as As(V). As and Cu follow the same time trend, while different for Cr. It is clear that the concentration of As increased in the groundwater after soil washing and that soil excavating have not the same problem with increased levels. The ground structure is changed and the clay mineral with adsorption surface is removed with soil washing. This could explain the increase of As in the groundwater. 

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    Dahlqvist examensarbete
  • 17.
    Davies, Neil S.
    et al.
    Department of Earth Sciences, University of Cambridge, Cambridge, UK.
    Gosse, John C.
    Department of Earth and Environmental Sciences, Dalhousie University, Halifax, Canada.
    Rouillard, Alexandra
    Lundbeck Foundation GeoGenetics Centre, GLOBE Institute, University of Copenhagen, Copenhagen, Denmark; Department of Geosciences, UiT—The Arctic University of Norway, Tromsø, Norway.
    Rybczynski, Natalia
    Department of Palaeobiology, Canadian Museum of Nature, Ottawa, Ontario K1P 6P4, Canada;6 Department of Biology and Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada.
    Meng, Jin
    Division of Paleontology, American Museum of Natural History, New York, New York, USA.
    REYES, ALBERTO V.
    Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada.
    Kiguktak, Jarloo
    Grise Fiord, Nunavut, Canada.
    Wood jams or beaver dams?: pliocene life, sediment and landscape interactions in the Canadian High Arctic2022Ingår i: Palaios, ISSN 0883-1351, E-ISSN 1938-5323, Vol. 37, nr 6, s. 330-347Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the mid-Pliocene (Zanclean, ca. ∼ 3.9 Ma), parts of the Canadian High Arctic experienced mean annual temperatures that were 14–22°C warmer than today and supported diverse boreal-type forests. The landscapes of this vegetated polar region left behind a fragmented sedimentary record that crops out across several islands in the Canadian Arctic Archipelago as the Beaufort Formation and correlative strata. Paleoecological information from these strata provides a high-fidelity window onto Pliocene environments, and prominent fossil sites yield unparalleled insights into Cenozoic mammal evolution. Significantly, many of the strata reveal evidence for life-sediment interactions in a warm-climate Arctic, most notably in the form of extensive woody debris and phytoclast deposits. This paper presents original field data that refines the sedimentological context of plant debris accumulations from the anactualistic High Arctic forests, most notably at the ‘Fyles Leaf Beds' and ‘Beaver Pond' fossil-bearing sites in the ‘high terrace deposits' of central Ellesmere Island. The former is a remarkably well-preserved, leaf-rich deposit that is part of a complex of facies associations representing lacustrine, fluvio-deltaic and mire deposition above a paleotopographic unconformity. The latter yields tooth-marked woody debris within a peat layer that also contains a rich assemblage of vertebrate and plant fossils including abundant remains from the extinct beaver-group Dipoides. Here we present sedimentological data that provide circumstantial evidence that the woody debris deposit at Beaver Pond could record dam-building in the genus, by comparing the facies motif with new data from known Holocene beaver dam facies in England. Across the Pliocene of the High Arctic region, woody debris accumulations are shown to represent an array of biosedimentary deposits and landforms including mires, driftcretions, woody bedforms, and possible beaver dams, which help to contextualize mammal fossil sites, provide facies models for high-latitude forests, and reveal interactions between life and sedimentation in a vanished world that may be an analogue to that of the near-future.

  • 18.
    Eckerberg, Katarina
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Nilsson, Måns
    Stockholm Environment Institute (SEI), Sweden; SEI's Policy and Institutions Programme, Sweden.
    Gerger-Swartling, Åsa
    Stockholm Environment Institute (SEI), Sweden.
    Söderberg, Charlotta
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Institutional analysis of energy and agriculture2007Ingår i: Environmental policy integration in practice: shaping institutions for learning / [ed] Måns Nilsson; Katarina Eckerberg, London: Earthscan Publications Ltd., 2007, 1, s. 111-136Kapitel i bok, del av antologi (Refereegranskat)
  • 19.
    Eckerlid, Sara
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Can understanding of catchment hydromorphology improve the success of Salmonidae spawning gravelrestoration?2024Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The long history of moderating watercourses to accommodate timber floating in northern Sweden lay the ground for river restorations. One restoration method is supplementing spawning gravel for Salmonidae to lay their eggs in. The success of Salmonidae reproduction is essential for the ecology in streams as well as for the economy and culture of Sweden. However, finding appropriate locations for the gravel beds, benefiting their longevity have been difficult. The aim of this study was to investigate if hydraulic and geomorphic characteristics influence mobility of 64 restored spawning beds in 11 streams in the Vindel River catchment, Sweden. Field measurements of the spawning beds condition were taken as percentage remaining and function. Metrics of fluvial power were calculated by geospatial analysis and compared to each other by a correlation model. A linear mixed effects model was made with belonging likelihood test comparing slope, drainage area, stream power proxy, distance to lake upstream, water depth over riverbed, channel width, restoration type and all variables together to the percentage remaining. The result showed that 84% of the spawning beds had moved while 71% of the beds were recorded as functioning. No significant correlation was found between any of the investigated variables by themselves or together and percentage remaining, suggesting other variables influenced mobility of the spawning gravel. Such as variations on a local-scale and variables connected to the northern hemisphere region. The lack of adequate data, subjectivity in the condition measurements and the proxy used for stream power also influenced the result.

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  • 20.
    Edin, Malin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Miljöpåverkan av äggproduktion: En jämförelse mellan Lilluns ägg och andra svenska äggproducenter2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The purpose of this report was to compare Lilluns egg production with other Swedish egg producers based on the flow of nutrients (nitrogen, phosphorus and potassium) in the egg production systems. The main focus in the report was the utilization rate of the forage and the excess of nutrients per kg egg. Additionally, the purpose was to identify the environmental impact from Lilluns egg production and compare the results with other egg producers. The inflow of nutrients associated with forage and poultry was compared with the nutrients that were exported from the production. All of the egg producers in this study had an excess of nutrients. The utilization rate of the forage for Lilluns egg was 47 %, the other egg producers in this study had an utilization rate between 45-50 %. The results showed that Lilluns egg had an excess of nitrogen of 0,04 kg/kg eggs. Lilluns egg also had an excess of phosphorus and potassium. The excess of phosphorus was 0,01 kg/kg eggs and 0,013 kg/kg eggs for potassium. The results showed that all the egg producers in this study had an excess of all the nutrients. The conclusion is that the egg production systems in this study have a similar utilization rate and the excess of nutrients per kg egg was also similar for all the egg producers.

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    fulltext
  • 21.
    Ehnvall, Betty
    et al.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, Umeå, Sweden.
    Ratcliffe, Joshua L.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, Umeå, Sweden.
    Bohlin, Elisabet
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, Umeå, Sweden.
    Nilsson, Mats B.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, Umeå, Sweden.
    Öquist, Mats G.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, Umeå, Sweden.
    Sponseller, Ryan A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Grabs, Thomas
    Department of Earth Sciences, Geocentrum, Uppsala University, Villavägen 16, Uppsala, Sweden.
    Landscape constraints on mire lateral expansion2023Ingår i: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 302, artikel-id 107961Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Little is known about the long-term expansion of mire ecosystems, despite their importance in the global carbon and hydrogeochemical cycles. It has been firmly established that mires do not expand linearly over time. Despite this, mires are often assumed to have expanded at a constant rate after initiation simply for lack of a better understanding. There has not yet been a serious attempt to determine the rate and drivers of mire expansion at the regional, or larger spatial scales. Here we make use of a natural chronosequence, spanning the Holocene, which is provided by the retreating coastline of Northern Sweden. By studying an isostatic rebound area we can infer mire expansion dynamics by looking at the portion of the landscape where mires become progressively scarce as the land becomes younger. Our results confirms that mires expanded non-linearly across the landscape and that their expansion is related to the availability of suitably wet areas, which, in our case, depends primarily on the hydro-edaphic properties of the landscape. Importantly, we found that mires occupied the wettest locations in the landscape within only one to two thousand years, while it took mires three to four thousand years to expand into slightly drier areas. Our results imply that the lateral expansion of mires, and thus peat accumulation is a non-linear process, occurring at different rates depending, above all else, on the wetness of the landscape.

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  • 22.
    Eklund, John
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Anläggning och Restaurering av fågelvåtmarker: Lokalisering av våtmarksobjekt i odlingslandskap som är lämpliga för restaurering och anläggning2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    There is a shortage of wetlands in the farming landscape and as a direct consequence farmland birds are decreasing in number. The need of restoring and constructing wetlands is therefore great. The purpose of this study was to locate potential objects in the farming landscape that is suitable for creating and restore wetland bird habitats within Västernorrland and Västerbotten County. A method was developed that stepwise pinpoint potential object in the agricultural landscape where seven selection parameters that define a suitable objects criterion where used. To evaluate the located objects a small number was observed in the field and furthermore a simulation of surface water was conducted to evaluate the landscape criteria’s and to calculate the land use. 98 objects were located, 59 restoration and 39 construction objects. The water surface simulation was conducted on four objects where one of the objects did not show favorable condition, this expresses the importance testing the objects early on. A large number of objects was located but the study indicates that there is possibly far more that object that wasn’t located that has good potential. The method has potential to develop higher accuracy and a ranking system. For the future this study suggests a 6 step work process to fully execute a wetland project, where this method constitutes the first step. 

  • 23.
    Ershammar, Ellen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Siporex inverkan på mobiliteten av arsenik och bly i fyllnadsmassor på Näsudden, Skelleftehamn.2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The expansion of an industrial area in Näsudden, Skelleftehamn, will require extensive groundwork. An old landfill in the area, partly consisting of autoclaved aerated concrete (siporex), is intended to be used for constructing the new industrial site. The conditions for how the material can be used is, however, controlled by a variety of parameters. This is a part study of the evaluation of how the masses should be treated. The purpose of this study is to evaluate how the presence of siporex affects the mobility of arsenic and lead in the landfill area. Soil and groundwater samples from 10 sample points from the landfill area were collected and analyzed for its metal content. The results were used for calculating the solid/liquid partition coefficient (Kd) for the desorption of samples with or without siporex. Results indicate that the mobility of arsenic is higher in the samples with siporex due to the higher pH in the leachate. No correlation could be found between the influence of siporex and mobility of lead in this study. Further studies are needed in a controlled environment to assess how siporex affects the mobility of arsenic and lead.

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  • 24.
    Fjällberg, Martina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Characteristics of instream wood following alluvial river restoration: Using Uncrewed Aerial Vehicles2023Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    River restoration is something that is often used to help restore watercourses that were historically used for timber floating. In these restorations, instream wood (IW) plays a big role in increasing biodiversity and habitat heterogeneity in watercourses. Uncrewed Aerial Vehicles (UAVs) have proven to be useful when monitoring changes following river restoration but there is a need for less time-consuming methods to detect IW. This study’s objective was to investigate IW following a river restoration in an alluvial reach in Vargån, Northern Sweden and how well UAVs can be used to do this. Manual digitizing of IW was done in GIS from orthomosaics of three different flight occasions: pre-restoration, directly after and one year after restoration. An object- and color-based automated image thresholding was done to investigate if it could be used to automatically detect IW. The results showed that there were differences in number of IW, volume, width, and length between the different flight occasions. There was also indication that there had been movement of IW as well as changes in cluster composition, with more clusters with a higher number of wood pieces in the latest flight occasion. The automated image thresholding was able to accurately detect IW with an accuracy of 47,4 %, but it had limitations due to natural conditions. However, it showed the possibility of using automated methods to detect IW and with improvements it could become a faster and more accessible way of detecting IW in river monitoring. 

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  • 25. Gilichinsky, Michael
    et al.
    Sandström, Per
    Reese, Heather
    Kivinen, Sonja
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Moen, Jon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Mats
    Mapping ground lichens using forest inventory and optical satellite data2011Ingår i: International Journal of Remote Sensing, ISSN 0143-1161, E-ISSN 1366-5901, Vol. 32, nr 2, s. 455-472Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lichen is a major forage resource for reindeer and may constitute up to 80% of areindeer’s winter diet. The reindeer grazing area in Sweden covers almost half of thecountry, with reindeer using mountainous areas in the summer and forested areas inthe winter. Knowledge about the spatial distribution of ground lichens is importantfor both practical and decision-making purposes. Since the early 1980s, remotesensing research of lichen cover in northern environments has focused on reindeergrazing issues. The objective of this study was to use lichen information collected inthe Swedish National Forest Inventory (NFI) as training data to classify opticalsatellite images into ground lichen cover classes. The study site was located within thereindeer husbandry area in northern Sweden and consisted of the common areabetween two contiguous Satellite Pour l’Observation de la Terre (SPOT)-5 scenesand one Landsat-7 Enhanced Thematic Mapper Plus (ETMþ) scene. Three classificationmethods were tested: Mahalanobis distance, maximum likelihood andspectral mixture analysis. Post-classification calibration was applied using a membershipprobability threshold in order to match the NFI-measured proportions oflichen coverage classes. The classification results were assessed using an independentlycollected field dataset (229 validation areas). The results demonstrated highclassification accuracy of SPOT imagery for the classification of lichen-abundantand lichen-poor areas when using theMahalanobis distance classifier (overall accuracy84.3%, kappa ¼ 0.68). The highest classification accuracy for Landsat wasachieved using a maximum likelihood classification (overall accuracy 76.8%, kappa¼ 0.53). These results provided an initial indication of the utility of NFI data astraining data in the process of mapping lichen classes over large areas.

  • 26.
    Gustavsson, Leif
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Mahapatra, Krushna
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Nair, Gireesh
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Implementering av energieffektiviseringsåtgärder i befintlig bebyggelse: Report prepared for the Swedish Energy Agency2010Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    There is great potential to improve energy efficiency in existing Swedish residential buildings. However, the successful implementation of efficiency measures depends on economical and technical factors, as well as on the attitudes and perceptions of the relevant actors. A better understanding of their attitudes and perceptions may influence the design of suitable policy measures that increase the adoption of energy efficiency measures. In this context, we conducted mail-in surveys completed by owners of detached houses, chairmen of co-operative housing associations (bostadsrättsförening) and municipality energy advisers in Sweden. We also interviewed window sellers/installers in Jämtland.

    Results show that it was important for the majority of homeowners to reduce their household energy use, with most undertaking no-cost measures (e.g., switching off lights). However, 70–90% of the responding homeowners had no intention of adopting building envelope measures over the next 10 years. The main reason for non-adoption was that homeowners were satisfied with the physical condition and thermal performance of their existing building envelope components. Homeowners who thought their energy cost was high were more likely to adopt an investment measure compared to those who thought their energy cost was low. Investment costs and annual energy cost savings were the most important factors in adoption of energy efficient building envelope measures. Therefore, economic incentives may induce homeowners to adopt energy efficiency investment measures. However, a large percentage (64%) of homeowners was unaware of the existence of government support for reducing household energy use. Information campaigns announcing the availability of economic incentives and the cost advantages of energy efficiency measures may be helpful in the adoption decision.

    Homeowners‘ considered interpersonal sources, builders, installers and energy advisers as important sources of information for their adoption of energy efficiency measures. Though a large percentage of respondents considered energy advisers as an important source of information, only 14% of homeowners had contacted an energy adviser in the past. Our findings suggest that the energy advice service is important for homeowners, but more efforts are needed to increase homeowners‘ awareness of and satisfaction with such services. The majority of municipal energy advisers were of the opinion that more training in technical aspects of energy issues and increased financial support could improve their performance.

    Installers and material suppliers are important actors in homeowners‘ adoption of energy efficiency measures. For example, approximately 53% of responding homeowners to a survey in Jämtland/Västernorrland stated that the window seller/installer from whom they had bought windows had recommended a particular type of window, and 97% had installed the windows that were recommended. The window sellers/installers in Jämtland prefer a window that is ―reasonably‖ energy efficient. They believe that windows with a U-value of 1.2 W/m2K are good and there is no reason to further improve the energy efficiency. The majority did not recommend windows with U-value <1.2 W/m2K. They were concerned about the condensation issues and high prices of such windows. This may influence the diffusion of very energy efficient windows in Swedish detached houses.

    About 80-95% of chairmen in co-operative housing associations who responded to our survey had no intention of adopting building envelope measures over the next 10 years. They were satisfied with the existing building envelope components, which may be one of the reasons for this lack of intention. As in the case of owners of detached houses, economic factors, like annual energy cost savings and investment costs, guide the implementation of energy efficiency investment measures in co-operative housing associations. However, about 66% of the responding chairmen did not consider financial constraint as a barrier to implementing investment intensive energy efficiency measures. For 54% of the respondents limited in-house competency to evaluate the benefits of energy efficiency measures was the main barrier.

    The majority of owners of detached houses (80%) and chairmen of co-operative housing associations (70%) perceived that economic policy instruments, such as investment subsidies and tax deductions, would encourage them to implement energy efficiency measures. Other policy instruments, especially information instruments, were perceived as less effective. Among various information policies, increasing the frequency of meter reading received the highest approval with 38% of homeowners, whereas approximately 41% of housing association chairmen thought that individual metering of heating and hot water use could be effective. Approximately 30% of homeowners and housing association chairmen thought that energy declaration was effective.

  • 27.
    Gydemo Östbom, Viktor
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Sedimentation in a small lake, more complex than previously assumed.: Bathymetrical and geochemical sediment analyses in Kassjön (63°55´ N, 20°01´ E).2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    For studies using lake sediments as a medium, understanding factors governing sediment distribution and properties is crucial for making accurate interpretations and conclusions. General lake sedimentation theory is however mainly based on larger lakes and systems, potentially leading to biased sampling and data interpretation when applied on a smaller system. In a paper published in 2008, Rippey et al. evaluated the fit of some general sedimentation theories on element distribution in the sediments of Kassjön (63°55´ N, 20°01´ E), northern Sweden. This small boreal lake reoccurs in the scientific literature, largely from paleolimnological studies on varved sediments in the lake, making the understanding of its sediment properties highly relevant. As part of a wider geochemical study on the lake, this paper scrutinizes the findings of Rippey et al. (2008) by using updated bathymetry and geochemical analyses, to provide further insight on sedimentation in Kassjön. Element composition, analysed with X-ray fluorescence spectrometry, and dry weight was obtained from sediment samples at 40 sites. Depth at sampling sites, together with catchment morphometry and previous bathymetry, was used to improve the bathymetric understanding. Kassjön was found to have a less steep bathymetry than previously assumed, with distribution of sediment geochemistry and dry weight showing heterogeneity differing from that expected of general sedimentation theories only. These results indicate that previous findings on sedimentation in Kassjön might be too simplistic, and that small-lake sedimentation is influenced by factors not included in general sedimentation models. Caution is therefore advised when e.g. interpreting the environmental record in lake sediments.

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    Sedimentation in a small lake, more complex than previously assumed
  • 28.
    Haverland, Freja
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Winter wheat exudates: Improving wheats resilience to drought2024Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Wheat (Triticum aestivum) is a crop that dominates the diets of about 35% of the world's human population. But wheat yields can be severely affected by drought. Therefore, in this experiment, root exudation of winter wheat was compared to find out how exudation changes during drought stress. This was done by using control plants that were compared to plants that experienced 8 days of drought and subsequently, 3 days of rewetting. Moreover, it was explored which one of two wheat genotypes, Capo or Aristaro, is better adapted to drought by measuring plant physiology and if beneficial rhizosphere microorganisms could help alleviate drought in wheat. Exudations were analysed using a photometer. It was found that drought and rewetting treatment influenced shoot dry weight, shoot water content, relative chlorophyll, as well as exuded phenols, sugars and amino acids. Aristaro was found to be more drought tolerant, because Aristaro plants had higher and more stable shoot water content, lower non-photochemical quenching (NPQ(T)), and exuded more phenols and amino acids, which could help recruit plant-growth promoting rhizobacteria. However, Capo might be able to avoid drought through early maturity and can therefore be used in regions where drought occurs later in the year. The implications of this experiment are therefore useful for improving wheats resilience to drought and food security with use of microorganisms.

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    Winter wheat exudates
  • 29.
    Helmersson, Alexandra
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Vattenskydd och krisberedskap hos allmän dricksvattenproduktion: Skydd av täkter, tillgång till reservvattentäkter och andra nödvattenlösningar hos svenska vattenproducenter2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The objective of this report was to analyse and compare vulnerability and preparation in Swedish municipal drinking water production, in case the commonly used water sources were inoperative. Methods used were a questionnaire and a less extensive study of regulations for water protection areas. The questionnaire was answered by 41 Swedish municipalities. A handful of them were companies co-owned by a few municipalities. Only one out of four municipalities had source protection areas to all their water sources and for many sources the protection was not satisfactory. Two municipalities in the study had no water sources of their own. Instead they bought all their drinking water from a company. This was considered an element of risk. It was also considered risky to have only a few water sources of the same type (groundwater or surface water). In this case it is extra important that there are other ways to prepare and deliver water. Half of the municipalities in the study had a substitute water source but an evaluation found half of these water sources deficient in at least one perspective. There were mainly three reasons why some municipalities did not have a water source substitute. These reasons were financial limitations, difficulties finding a water source with enough capacity and that the preparation had been found adequate without a water source substitute. The last argument was the most common and has occasionally been found accurate. One third of all the municipalities were still inadequately prepared for possible emergencies affecting water production.

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    fulltext
  • 30. Hilding-Rydevik, Tuija
    et al.
    Moen, Jon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Green, Carina
    Baselines and the shifting baseline syndrome: exploring frames of reference in nature conservation2018Ingår i: Issues and concepts in historical ecology: the past and future of landscapes and regions / [ed] Carole L. Crumley, Tommy Lennartsson, Anna Westin, Cambridge University Press, 2018, s. 112-141Kapitel i bok, del av antologi (Refereegranskat)
  • 31.
    Horstkotte, Tim
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Moen, Jon
    Lämås, Tomas
    Helle, Timo
    The legacy of logging-estimating arboreal lichen occurrence in a boreal multiple-use landscape on a two century scale2011Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 6, nr 12, s. e28779-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In northern Sweden, the availability of arboreal lichens (Bryoria fuscescens, Alectoria sarmentosa) as winter grazing resources is an important element in reindeer husbandry. With the industrialization of forestry, forests rich in arboreal lichens have diminished considerably. Here, we analyze how forestry has impacted lichen availability from the 1920's to the present day and model its future development assuming different forest management scenarios. We recorded the current occurrence of B. fuscescens in 144 sampling plots, stratified by forest age class and dominant tree species in a 26,600 ha boreal forest landscape that is used for both reindeer herding and forestry. Lichen abundance was visually estimated in four classes: none, sparse, moderate and abundant. A binary logistic model using forest age as the independent variable was developed to predict the probability of lichens being present. Using this model, we found that lichens were present in stands that are at least 63 years old. Because of the relative paucity of stands rich in arboreal lichens, it was not possible to reliably determine how age affects the variation in abundance of older forest stands. The historical development of forests where arboreal lichens could potentially occur was studied using historic forestry records dating back 80 years. Between 1926 and the present day, forestry has reduced the cover of forests older than 60 years from 84% to 34%. The likely future spatial coverage of these stands over the next 120 years was estimated for two different management scenarios and an unmanaged reference scenario, using the Heureka strategic planning program. Under both the "business as usual'' scenario and that involving more intensive forestry, continued decreases in lichen availability are projected. Our results emphasize the importance of alternative forestry practices, such as prolonged rotation periods, to increase the availability of arboreal lichens as a grazing resource for reindeer.

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  • 32. Jiang, Tao
    et al.
    Skyllberg, Ulf
    Björn, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Green, Nelson W.
    Tang, Jianhui
    Wang, Dingyong
    Gao, Jie
    Li, Chuxian
    Characteristics of dissolved organic matter (DOM) and relationship with dissolved mercury in Xiaoqing River-Laizhou Bay estuary, Bohai Sea, China2017Ingår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 223, s. 19-30Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract Because of heterogeneous properties, dissolved organic matter (DOM) is known to control the environmental fate of a variety of organic pollutants and trace metals in aquatic systems. Here we report absorptive and fluorescence properties of DOM, in concurrence with concentrations of dissolved mercury (Hg), along the Xiaoqing River-Laizhou Bay estuary system located in the Bohai Sea of China. A mixing model consisting of the two end-members terrestrial and aquatic DOM demonstrated that terrestrial signatures decreased significantly from the river into the estuary. Quasi-conservative mixing behavior of DOM sources suggests that the variations in the average DOM composition were governed by physical processes (e.g., dilution) rather than by new production and/or degradation processes. In contrast to some previous studies of river-estuary systems, the Xiaoqing River-Laizhou Bay estuary system displayed a non-significant correlation between DOM and Hg quantities. Based on this and the variation of Hg concentration along the salinity gradient, we concluded that Hg showed a non-conservative mixing behavior of suggested end-member sources. Thus, rather than mixing, Hg concentration variations seemed to be controlled by biogeochemical processes.

  • 33.
    Johansson, Eva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Samband mellan vulkanutbrott och klimatförändringar: Analys och värdering av teorier om vulkanisk aska och gasers påverkan på det globala klimatet2015Självständigt arbete på avancerad nivå (masterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This literature review analyses and discusses different theories and results regarding impact of volcanic eruptions on climate change in Earth's history. Present global warming has been attributed to anthropogenic emissions of greenhouse gases, mainly carbon dioxide, however changes in global temperatures have occurred before the onset of anthropogenic emissions. Certain prehistoric climate changes are thought to be caused by emissions of volcanic gases to the atmosphere. Many studies have investigated the connection between volcanic events and subsequent changes in global temperatures. A majority have concluded that volcanic sulfur dioxide is the main direct and indirect climate forcing gas influencing temperatures over time. Increased volcanic activity over the last 15 years is thought to be an inhibiting factor on present global warming. This is supported by evidence of past volcanic events preceding global cooling and warming periods during Holocene and prehistoric times. Further, there are indications that factors such as geographical position, season, gas composition, magnitude and duration of an eruption influences the extent of the climate forcing.Records of climate such as ice cores and tree growth rings and isotopic characterization have made it possible to identify volcano eruptions over time and determine the identity of the erupting volcano. Past and present data from these can be used to gain a better understanding of past climate changes as well as making predictions about future changes as a result volcanic eruptions. However, accuracy regarding temporal and spatial resolution of these records is of great importance for the validity of the results.

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  • 34.
    Johansson, June
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Sediment chemistry and the potential toxicity to benthic invertebrates in sediments affected by acid sulfate soils: A study on freshwater and marine sediments in Västerbotten, Sweden2020Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The leakages of metals from acid sulfate soils and their potential toxicity to benthic invertebrates were studied in the sediment profiles of Lillkvasjön and Lövselefjärden - a lake and an estuary known to be affected by acid sulfate soils - in Västerbotten, northern Sweden. The concentrations of 25 different elements were analyzed throughout both sediment profiles through X-Ray Fluorescence (XRF) Spectrometer analysis. Organic matter was measured through loss-on-ignition (LOI). By performing correlation analysis and normalizations to LOI on all sediment variables, Cu, Fe, Ni, Pb, S and Zn were found to be leached from acid sulfate soils to both sites, while Mg and Mn were related to leakages from acid sulfate soils in Lövselefjärden. The concentrations of Cu (195 mg kg-1), Ni (55 mg kg-1), Pb (90 mg kg-1) and Zn (398 mg kg-1) in the surface sediment of Lövselefjärden were classified as potentially toxic to benthic invertebrates. In Lillkvasjön, Cu (210 mg kg-1) and Ni (87 mg kg-1) were classified to have an increased risk of negative impacts on benthic invertebrates, while the concentrations of Pb (121 mg kg-1) and Zn (329 mg kg-1) were likely to low to have any negative effects. These results strengthen previous finds of impacts from acid sulfate soils in the two catchment areas and elucidate the importance of further studies on the impact of acid sulfate soils on benthic invertebrates.

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  • 35. Johansson, Therese
    et al.
    Andersson, Jon
    Hjältén, Joakim
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ecke, Frauke
    Short-term responses of beetle assemblages to wildfire in a region with more than 100 years of fire suppression2011Ingår i: Insect Conservation and Diversity, ISSN 1752-458X, Vol. 4, nr 2, s. 142-151Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Suppression of wildfires in boreal landscapes has become widespread and has seriously affected many fire favoured species. However, little is known about the response of organism assemblages to large wildfires in regions with a long history of effective fire suppression, such as Scandinavia.

    2. We studied the short-term effects of a >1600 ha wildfire on beetle assemblages in northern Sweden. The first summer after fire, beetles were sampled in 12 sites using 36 large window traps, half in old pine forest stands in the burned area and half in similar, but unburned control stands. The entire beetle assemblage and eight subgroups were analysed: saproxylics, non-saproxylics, moderately fire favoured, strongly fire favoured, fungivores, predators, cambium consumers and red-listed species.

    3. Species composition differed markedly between burned and unburned forests in all nine groups. Furthermore, beetle abundance was higher in the burned area for the entire assemblage and for saproxylics, both groups of fire favoured species, predators and cambium consumers. Species number was higher only for non-saproxylics, strongly fire favoured species and cambium consumers.

    4. Our results show that wildfire has rapid and strong effects on a wide range of beetles. However, we only trapped two individuals of fire-dependent beetles, which may suggest a lack of such species in the region, possibly due to >100 years of fire suppression. At the regional scale, the studied wildfire may potentially increase the abundance of these beetles after a longer period of reproduction in the burned area.

  • 36. Jones, Elizabeth A.
    et al.
    Westin, Anna
    Madry, Scott
    Murray, Seth
    Moen, Jon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Tickner, Amanda
    How to operationalise collaborative research2018Ingår i: Issues and concepts in historical ecology: the past and future of landscapes and regions / [ed] Carole L. Crumley, Tommy Lennartsson, Anna Westin, Cambridge University Press, 2018, s. 240-271Kapitel i bok, del av antologi (Refereegranskat)
  • 37.
    Jonsson, Sofia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Tracing late Holocene changes in lake-water total organic carbon: A multi-proxy approach based on sediment bio-geochemistry and a faecal biomarker2015Självständigt arbete på avancerad nivå (masterexamen), 40 poäng / 60 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Long-term dynamics of lake-water total organic carbon (LW-TOC) concentrations in freshwater lakes provide an important perspective on the recent increases in LW-TOC observed in many of these systems and may assist with the identification of natural and anthropogenic drivers of change. This study examines how LW-TOC in Dragsjön, a lake situated in an area with a long history of anthropogenic land use, has changed in response to natural and anthropogenic perturbations throughout the Holocene. To provide a better understanding of the processes involved, a multi-proxy study was conducted and included multi-element geochemistry (17 major and trace elements), biogenic silica, organic matter (OM) content and composition, and the faecal biomarker “coprostanol”. The direct biomarker for anthropogenic presence, “coprostanol”, and a detailed characterisation of OM composition are for the first time applied for tracing changes in LW-TOC. Natural processes contributed to stable LW-TOC concentrations in Dragsjön for most part of the Holocene. Humans were present in the catchment from AD 100 as indicated by coprostanol, but did not begin to affect LW-TOC until c. AD 1500. In the last 500 years LW-TOC steadily declined from 17 to 10 mg L-1 in response to anthropogenic alterations to the terrestrial biomass balance. The increase in LW-TOC during the last 70 years likely represents a recovery from anthropogenic disturbance rather than a baseline shift in response to any of the number of proposed recent stressors. The faecal biomarker coprostanol and OM composition provided information essential for identifying and characterising the effects of anthropogenic disturbance.

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  • 38. Joshi, Jaideep
    et al.
    Brännström, Åke
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för matematik och matematisk statistik. Evolution and Ecology Program, International Institute for Applied Systems Analysis, Laxenburg, Austria.
    Dieckmann, Ulf
    Emergence of social inequality in the spatial harvesting of renewable public goods2020Ingår i: PloS Computational Biology, ISSN 1553-734X, E-ISSN 1553-7358, Vol. 16, nr 1, artikel-id e1007483Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Spatially extended ecological public goods, such as forests, grasslands, and fish stocks, are at risk of being overexploited by selfish consumers-a phenomenon widely recognized as the 'tragedy of the commons.' The interplay of spatial and ecological dimensions introduces new features absent in non-spatial ecological contexts, such as consumer mobility, local information availability, and strategy evolution through social learning in neighborhoods. It is unclear how these features interact to influence the harvesting and dispersal strategies of consumers. To answer these questions, we develop and analyze an individual-based, spatially structured, eco-evolutionary model with explicit resource dynamics. We report the following findings. (1) When harvesting efficiency is low, consumers evolve a sedentary consumption strategy, through which the resource is harvested sustainably, but with harvesting rates far below their maximum sustainable value. (2) As harvesting efficiency increases, consumers adopt a mobile 'consume-and-disperse' strategy, which is sustainable, equitable, and gives maximum sustainable yield. (3) A further increase in harvesting efficiency leads to large-scale overexploitation. (4) If costs of dispersal are significant, increased harvesting efficiency also leads to social inequality between frugal sedentary consumers and overexploitative mobile consumers. Whereas overexploitation can occur without social inequality, social inequality always leads to overexploitation. Thus, we identify four conditions that-while being characteristic of technological progress in modern societies-risk social inequality and overexploitation: high harvesting efficiency, moderately low costs of dispersal, high consumer density, and the tendency of consumers to adopt new strategies rapidly. We also show how access to global information-another feature widespread in modern societies-helps mitigate these risks.

    Author summary: Throughout history, humans have shaped ecological landscapes, which in turn have influenced human behavior. This mutual dependence is epitomized when human consumers harvest a spatially extended renewable resource. Simple models predict that, when multiple consumers harvest a shared resource, each is tempted to harvest faster than his/her peers, putting the resource at risk of overexploitation. It is unclear, however, how the interplay among resource productivity, consumer mobility, and social learning in spatial ecological public goods games influences evolved consumer behavior. Here, using an individual-based, spatially structured, eco-evolutionary model of consumers and a resource, we find that increasing resource productivity initially promotes efficient resource use by enabling mobile consumption strategies, but eventually leads to inequality and overexploitation, as overexploitative mobile consumers coexist with frugal sedentary consumers. When consumers are impatient (i.e., eager to imitate successful strategies) or myopic (i.e., unaware of conditions outside of their neighborhoods), inequality and overexploitation tend to aggravate.

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  • 39.
    Kampezidou, Dimitra
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Spatial distribution of heavy metals in surface marine sediments in the Mediterranean region2015Självständigt arbete på avancerad nivå (masterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Several scientific articles were mainly reviewed from Umeå’ s university database in order to determine the distribution, degree of contamination, and the sources of 7 selected heavy metals (Cr, Pb, Cu, Zn, Cd, Hg, Ni) in surface sediments along the coasts of the Mediterranean Sea. The Enrichment factor (EF) was used as pollution indicator to evaluate the extent of metal contamination in all the investigated areas. According to Abrahim and Parker (2008) the EF is defined as the ratio of the determined metal to Al (or Fe) in the sample divided by the ratio of background metal to background Al (or Fe) ratio. According to the results of this study, EF values for Cr, Pb, Cu, Cd and Ni presented an upward trend along the west to east shoreline of the Mediterranean sea, whereas Zn and Hg EF values showed a downward trend along this region. Cr generally exhibited no enrichment in places to the west (EF<1.5) whereas in the eastern side displayed moderate enrichment (EF=1.95). Pb EF values showed moderate enrichment (EF=5) along the western section of the sea, whilst in the eastern part revealed significant enrichment (5.45). Zn pollution levels were minimal (EF=1.6) in places to the west and moderate (EF=2.2) to the east. The enrichment for Cd was considered moderate in the western part of the basin and significant in the eastern section. These heavy metals distribution can be explained by the fact that different inputs (mainly due to anthropogenic activities) from the inshore environment may take place in each area of the sea. However, Cu and Ni presented the same degree of pollution (moderate) in the whole sea, presumably indicating similar Cu and Ni inputs from the terrestrial environment. However, conclusions for Hg were not possible to be drawn as the collected data were not sufficient. 

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  • 40.
    Keskitalo, E Carina H
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för geografi och ekonomisk historia.
    Pettersson, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för geografi och ekonomisk historia.
    Can adaptation to climate change at all be mainstreamed in complex multi-level governance systems?: A case study of forest-relevant policies at the EU and Swedish levels2016Ingår i: Implementing climate change adaptation in cities and communities: integrating strategies and educational approaches / [ed] Walter Leal Filho, Kathryn Adamson, Rachel M. Dunk, Ulisses M. Azeiteiro, Sam Illingworth, Fátima Alves, Basel: Springer, 2016, s. 53-74Konferensbidrag (Refereegranskat)
    Abstract [en]

    Mainstreaming adaptation to climate change in forest-relevant policy can be as a "most difficult" case, relevant for asking the question to extent to which adaptation can at all be mainstreamed in complex multi-level governance systems. This study examines the case of to what extent EU and national (exemplified by Swedish) legal and policy frameworks are able to integrate with each other in ways that may support climate change adaptation in forests. To move as close to the real life situation of mainstreaming challenges as possible, the study focuses on not only one area of mainstreaming or integration, but on the three broad policy areas: (a) adaptation per se; (b) forest biodiversity and habitat protection with respect to invasive species; and (c) water protection in relation to forest use. The study concludes that conflicts between international legal principles such as precaution and free trade, as well as distribution of competences at EU and national level, results in a great discrepancy in terms of opportunities for a nation to effectively act independently as well as for effectively integrating adaptation aims in the connected EU-national systems.

  • 41.
    Kilpatrick, Douglas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    The effects of population growth on Ecosystem services in lake Ekoln: A multi-proxy data analysis of a lake core and historical records.2016Självständigt arbete på avancerad nivå (masterexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Throughout human history man has utilized the environment to varying degrees, depending on technology and population. These ¨ecosystem services¨ have suffered sustained degradation over the centuries, resulting in large investments having to be made to prevent and reverse further changes to the environment. Few studies have attempted to quantitatively compare how these changes, occurring long before modern environmental monitoring programs started, affected important ecosystem services such as species diversity, water quality, carbon burial and soil stability. The aims of this study were to i) assess whether human impact on ecosystem services have varied over time in perspective of relative change, and ii) to assess the individual (per capita) contributions. I used multiple sediment proxies from a 6 m C¹⁴-dated core collected from lake Ekoln, South-Central Sweden, to reconstruct environmental changes while tracking the population growth in the city of Uppsala during the last ten centuries. Through the use of pollen and diatom assemblages I reconstructed the changing terrestrial and aquatic diversities over time, while sediment accumulation rates and the X-ray fluorescence spectroscopy of the sediment was used to reconstruct soil stability, carbon burial and water quality, respectively. In the latter case, sediment phosphorus concentrations were used as a proxy for freshwater eutrophication while metals (mercury and lead) were used to infer inputs of toxic pollutants. Finally, I normalized (z) all data to create meta-data. The z-values and reconstructed population for Uppsala made it possible to differentiate 5 unique time periods based on anthropogenic induced change, which were not previously visible in the data, and all of which have been linked to the most likely historical causes, including the Black Death. The results show that the most significant anthropogenic impacts in terms of pollution volume occurred in the 1960s, while the period from 1200-1500 AD saw the most significant environmental change in terms per head of capita, most likely caused by the shift from woodland to open landscape through twiddening, a process of burning forest to create agricultural land, prior to 1500 AD. Moreover, rapid recovery is visible after the implementation of environmental policies from the 1970s onwards.

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  • 42. Kuba, Matthias
    et al.
    He, Hanbing
    Kirnbauer, Friedrich
    Boström, Dan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Ohman, Marcus
    Hofbauer, Hermann
    Deposit build-up and ash behavior in dual fluid bed steam gasification of logging residues in an industrial power plant2015Ingår i: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 139, s. 33-41Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A promising way to substitute fossil fuels for production of electricity, heat, fuels for transportation and synthetic chemicals is biomass steam gasification in a dual fluidized bed (DFB). Using lower-cost feedstock, such as logging residues, instead of stemwood, improves the economic operation. In Senden, near Ulm in Germany, the first plant using logging residues is successfully operated by Stadtwerke Ulm. The major difficulties are slagging and deposit build-up. This paper characterizes inorganic components of ash forming matter and draws conclusions regarding mechanisms of deposit build-up. Olivine is used as bed material. Impurities, e.g., quartz, brought into the fluidized bed with the feedstock play a critical role. Interaction with biomass ash leads to formation of potassium silicates, decreasing the melting temperature. Recirculation of coarse ash back into combustion leads to enrichment of critical fragments. Improving the management of inorganic streams and controlling temperature levels is essential for operation with logging residues. (C) 2015 Elsevier B.V. All rights reserved.

  • 43.
    Kullman, Leif
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Treeline (Pinus sylvestris) landscape evolution in the Swedish Scandes - a 40-year demographic effort viewed in a broader temporal context2014Ingår i: Norsk Geografisk Tidsskrift, ISSN 0029-1951, E-ISSN 1502-5292, Vol. 68, nr 3, s. 155-167Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The article reports the outcome of long-term demographic monitoring of elevational treeline ecotonal stands of Scots pine (Pinus sylvestris L.) in the southern Swedish Scandes. Annual censuses were undertaken of recruitment, mortality, growth, seed viability, and causes of mortality during the period 1973-2012 in a set of 18 permanent plots. A net gain in total population size occurred over the study period as the result of periodic fluctuations in recruitment and mortality, broadly congruent with annual variations in summer and winter temperatures. Summer temperatures affected seed viability, establishment, and height growth. Winter temperatures exerted an impact foremost by changing the incidence of winter desiccation injury. As a result of infilling, pine has become a more prominent and vital component of the landscape around the forest limit, which has advanced insignificantly into the bordering mountain birch forest. The results highlight a rigid climate-forest disequilibrium and falsify models suggesting extensive and swift expansion of the treeline ecotone and closed forest at the expense of alpine tundra in response to anticipated future warming during the present century. The balance of evidence suggests that patchy forest expansion is likely to occur at a very slow (plurisecular) pace, given that climate warming prevails.

  • 44.
    Kumpula, Kimmo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ancient DNA in paleosols, SW Greenland: A tool for retrospective paleoenvironmental studies?2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Ancient DNA (aDNA) is a useful tool for retrospective paleoenvironmental studies. Paleosols formed in Arctic environments constitute a potential archive of aDNA from terrestrial organisms living in past environments, given that the cold and dry climate prevailing at high latitudes favors DNA preservation and hamper post-depositional mobility of deposited fragments. However, to what extent aDNA is preserved in old buried soil layers (paleosol layers) are not well known. This study asses to what extent DNA older than 100 years is present in a paleosol profile from southwest Greenland. My main hypothesis was that aDNA from both plants and animals could be extracted from old buried soil layers. I found that oldest studied soil layers were more than 800 B.P. yr old. These old layers contained DNA from both plants and animals. The clean sampling protocol used showed no signs of contamination, suggesting that the DNA was from soil layers and not from modern contaminants. I conclude that my hypothesis seems valid and that a majority of the analyzed plant and animal DNA is ancient. Indeed, aDNA could be used to infer species presence in past paleoenvironments and widen our knowledge regarding how Arctic organism coped with climatic perturbations and thus, improve our understanding how they will respond to future climatic change.

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  • 45.
    Larsson, Cecilia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    The importance of winter for carbon emissions from boreal lakes2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this study was to investigate the importance of winter season for the production of carbon dioxide (CO2) and methane (CH4) in humic and clear-water boreal aquatic systems. The study was conducted in 16 experimental ponds in northern Sweden during the winter of 2013. Half of the ponds had a higher concentration of dissolved organic carbon (DOC). CO2, CH4, DOC and dissolved inorganic carbon (DIC) were measured repeatedly under the ice from January to April. The results show that CO2 was accumulated continually during winter. No difference in winter accumulation were found between humic and clear ponds. CH4 was rarely accumulated in neither humic nor clear ponds, and was not an important part of the gas flux at spring ice melt. At ice melt, the flux from humic ponds accounted for 1.6 g C m-2 and 1.7 g C m-2 from clear ponds, which was equivalent for 15.6% respective 100% of the annual gas emissions. On a whole-year basis humic ponds acted as a source of 10.3 g C m-2, while clear ponds acted as a sink of 14.7 g C m-2. 76 mg m-2 d-1 DOC was consumed in humic and 59 mg m-2 d-1 DOC in clear ponds while the DIC accumulation was 125 mg m-2 d-1 in humic and 118 mg m-2 d-1 in clear ponds. This study stresses the importance of ice-covered boreal aquatic systems as a significant parts of the global carbon cycling.

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    Larsson 2013 master thesis
  • 46.
    Lehman, Hanna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Assuandammens påverkan på Nilen, Egypten2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Regulation of rivers by dams and reservoirs is a good example where anthropogenic impact could be considerable both in the local environment, but also has major implications upstream and downstream. This study was accomplished as a literature study of the river Nile, which is extremely important for water supply. The purpose of this study was to investigate the consequences of the construction of the Aswan High Dam, to obtain a consistent flow for water supply, irrigation and power generation in Egypt. Since Egypt has a very hot and dry climate large amounts of water in reservoir is lost to the Nubian aquifer system and by evaporation. The consequences from constructing the dam are considerable. It has led to the preventing of the annual flooding and a significant reduction in sediment load reaching the outer delta, which has led to an erosion of the delta front. The incoming waves create a current, mainly towards the east, carrying away the eroded material. In order to protect the delta front seawalls and breakwaters has been built. They have stopped the erosion of the areas behind them, but it has also led to the erosion of other areas.

    The issues in Egypt reflect the global crisis, mainly in delta areas, which prevail in regulated rivers. The biggest issue globally is the reduced sediment transport to the coast that causes land loss. 

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    Assuandammens påverkan på Nilen, Egypten
  • 47. Lennartsson, Tommy
    et al.
    Eriksson, Ove
    Iuga, Anamaria
    Larsson, Jesper
    Moen, Jon
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Scholl, Michael D.
    Westin, Anna
    Crumley, Carole L.
    Diversity in ecological and social contexts2018Ingår i: Issues and concepts in historical ecology: the past and future of landscapes and regions / [ed] Carole L. Crumley, Tommy Lennartsson, Anna Westin, Cambridge University Press, 2018, s. 182-239Kapitel i bok, del av antologi (Refereegranskat)
  • 48. Lenoir, Jonathan
    et al.
    Graae, Bente Jessen
    Aarrestad, Per Arild
    Alsos, Inger Greve
    Armbruster, W. Scott
    Austrheim, Gunnar
    Bergendorff, Claes
    Birks, H. John B.
    Brathen, Kari Anne
    Brunet, Jorg
    Bruun, Hans Henrik
    Dahlberg, Carl Johan
    Decocq, Guillaume
    Diekmann, Martin
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ejrnaes, Rasmus
    Grytnes, John-Arvid
    Hylander, Kristoffer
    Klanderud, Kari
    Luoto, Miska
    Milbau, Ann
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Moora, Mari
    Nygaard, Bettina
    Odland, Arvid
    Ravolainen, Virve Tuulia
    Reinhardt, Stefanie
    Sandvik, Sylvi Marlen
    Schei, Fride Hoistad
    Speed, James David Mervyn
    Tveraabak, Liv Unn
    Vandvik, Vigdis
    Velle, Liv Guri
    Virtanen, Risto
    Zobel, Martin
    Svenning, Jens-Christian
    Local temperatures inferred from plant communities suggest strong spatial buffering of climate warming across Northern Europe2013Ingår i: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 19, nr 5, s. 1470-1481Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies from mountainous areas of small spatial extent (<2500km2) suggest that fine-grained thermal variability over tens or hundreds of metres exceeds much of the climate warming expected for the coming decades. Such variability in temperature provides buffering to mitigate climate-change impacts. Is this local spatial buffering restricted to topographically complex terrains? To answer this, we here study fine-grained thermal variability across a 2500-km wide latitudinal gradient in Northern Europe encompassing a large array of topographic complexities. We first combined plant community data, Ellenberg temperature indicator values, locally measured temperatures (LmT) and globally interpolated temperatures (GiT) in a modelling framework to infer biologically relevant temperature conditions from plant assemblages within <1000-m2 units (community-inferred temperatures: CiT). We then assessed: (1) CiT range (thermal variability) within 1-km2 units; (2) the relationship between CiT range and topographically and geographically derived predictors at 1-km resolution; and (3) whether spatial turnover in CiT is greater than spatial turnover in GiT within 100-km2 units. Ellenberg temperature indicator values in combination with plant assemblages explained 4672% of variation in LmT and 9296% of variation in GiT during the growing season (June, July, August). Growing-season CiT range within 1-km2 units peaked at 6065 degrees N and increased with terrain roughness, averaging 1.97 degrees C (SD=0.84 degrees C) and 2.68 degrees C (SD=1.26 degrees C) within the flattest and roughest units respectively. Complex interactions between topography-related variables and latitude explained 35% of variation in growing-season CiT range when accounting for sampling effort and residual spatial autocorrelation. Spatial turnover in growing-season CiT within 100-km2 units was, on average, 1.8 times greater (0.32 degrees Ckm1) than spatial turnover in growing-season GiT (0.18 degrees Ckm1). We conclude that thermal variability within 1-km2 units strongly increases local spatial buffering of future climate warming across Northern Europe, even in the flattest terrains.

  • 49.
    Lidberg, William
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Deglaciationen av ett område på västra Grönland: Deglaciationen av ett område på västra Grönland2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this report is to describe the deglaciation in an area on west Greenland in the vicinity of Kangerlussuaq. To do this, the geomorphological landforms were mapped by studying areal photographs and by a two week field study where key areas were examiend. The landforms were transferred to a map using ArcGis and each key area were interpreted.The majority of the geomorphological formations were formed during the last deglaciation and consists of morain ridges, kettle topography in both till and glacifluvium, glacifluvial deltas, two fossil sandurs, and lateral terraces. Based on key areas and an inversion model a geomorphological map was created to illustrate the deglaciation, using the least complex explanation of the genesis of the landforms. The results show that the ice played a major role by damming lakes which enabled formation of many meltwater chanels and delta formations on higher elevations. The morain ridges and lateral terraces showed the extent of the ice margin during the halts in the ice retreat. The deglaciation was dated with help from earlier studies and the conclusion was that the deglaciation started between 7900 and 6700 yr BP. And the area was free from ice 7100-6500 yrs BP.

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    William Lidberg Examensarbete
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  • 50.
    Linda, Engström
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Effects of forestry on stream water chemistry during autumn: A before and after comparison between a reference and two streams with clear-cut watershed areas2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Forestry is a large-scale business in many countries, and in northern Sweden a large portion of the Boreal forests is cut. Yet very few studies have investigated the impacts of forestry on the vast number of receiving stream waters. This study has therefore investigated the impacts of forestry, through clear-cutting, on stream water chemistry during autumn conditions in northern Sweden. The study compares the parameters water height, absorbance, dissolved organic carbon, total dissolved nitrogen and total phosphorus in two inlet streams in recently deforested sites, <1 year ago, and an undisturbed reference inlet stream. The disturbed inlet streams are compared to the reference inlet stream the year before and after clear-cutting. This study shows that during a 15- day period from late August to the beginning of September, water height was increased in both disturbed inlet streams, indicative of a higher run-off post-harvest. Absorbance showed a large decrease post-harvest in the disturbed inlet streams. Total dissolved nitrogen and total phosphorus concentrations decreased slightly after clear-cut in both disturbed inlet streams. The effect was probably larger for phosphorus, since the seasonal variation in the reference was larger in 2013. DOC concentrations increased slightly in one of the disturbed inlet streams in 2013, but decreased slightly in the other disturbed inlet stream. The increased run-off was therefore not followed by a higher DOC and nutrient leakage. Results suggest that during a short period in the autumn, harvest does not seem to lead to increased DOC and nutrient losses to receiving stream waters.

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