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  • 301.
    De La Torre, Amanda
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Vancouver, BC, Canada.
    Ingvarsson, Pär
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Aitken, S. N.
    Vancouver, BC, Canada.
    Genetic architecture and genomic patterns of gene flow between hybridizing species of Picea2015Inngår i: Heredity, ISSN 0018-067X, E-ISSN 1365-2540, Vol. 115, nr 2, s. 153-164Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hybrid zones provide an opportunity to study the effects of selection and gene flow in natural settings. We employed nuclear microsatellites (single sequence repeat (SSR)) and candidate gene single-nucleotide polymorphism markers (SNPs) to characterize the genetic architecture and patterns of interspecific gene flow in the Picea glauca x P. engelmannii hybrid zone across a broad latitudinal (40-60 degrees) and elevational (350-3500 m) range in western North America. Our results revealed a wide and complex hybrid zone with broad ancestry levels and low interspecific heterozygosity, shaped by asymmetric advanced-generation introgression, and low reproductive barriers between parental species. The clinal variation based on geographic variables, lack of concordance in clines among loci and the width of the hybrid zone points towards the maintenance of species integrity through environmental selection. Congruency between geographic and genomic clines suggests that loci with narrow clines are under strong selection, favoring either one parental species (directional selection) or their hybrids (overdominance) as a result of strong associations with climatic variables such as precipitation as snow and mean annual temperature. Cline movement due to past demographic events (evidenced by allelic richness and heterozygosity shifts from the average cline center) may explain the asymmetry in introgression and predominance of P. engelmannii found in this study. These results provide insights into the genetic architecture and fine-scale patterns of admixture, and identify loci that may be involved in reproductive barriers between the species.

  • 302.
    De La Torre, Amanda R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Univ British Columbia, Dept Forest & Conservat Sci, Ctr Forest Conservat Genet, Vancouver, BC V6T 1Z4, Canada.
    Roberts, David R.
    Aitken, Sally N.
    Genome-wide admixture and ecological niche modelling reveal the maintenance of species boundaries despite long history of interspecific gene flow2014Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, nr 8, s. 2046-2059Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The maintenance of species boundaries despite interspecific gene flow has been a continuous source of interest in evolutionary biology. Many hybridizing species have porous genomes with regions impermeable to introgression, conferring reproductive barriers between species. We used ecological niche modelling to study the glacial and postglacial recolonization patterns between the widely hybridizing spruce species Picea glauca and P.engelmannii in western North America. Genome-wide estimates of admixture based on a panel of 311 candidate gene single nucleotide polymorphisms (SNP) from 290 genes were used to assess levels of admixture and introgression and to identify loci putatively involved in adaptive differences or reproductive barriers between species. Our palaeoclimatic modelling suggests that these two closely related species have a long history of hybridization and introgression, dating to at least 21000years ago, yet species integrity is maintained by a combination of strong environmental selection and reduced current interspecific gene flow. Twenty loci showed evidence of divergent selection, including six loci that were both F-st outliers and associated with climatic gradients, and fourteen loci that were either outliers or showed associations with climate. These included genes responsible for carbohydrate metabolism, signal transduction and transcription factors.

  • 303. De Laender, F.
    et al.
    Verschuren, D.
    Bindler, Richard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Thas, O.
    Janssen, C. R.
    Biodiversity of Freshwater Diatom Communities during 1000 Years of Metal Mining, Land Use, and Climate Change in Central Sweden2012Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 16, s. 9097-9105Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We subjected a unique set of high-quality paleoecological data to statistical modeling to examine if the biological richness and evenness of freshwater diatom communities in the Falun area, a historical copper (Cu) mining region in central Sweden, was negatively influenced by 1000 years of metal exposure. Contrary to ecotoxicological predictions, we found no negative relation between biodiversity and the sedimentary concentrations of eight metals. Strikingly, our analysis listed metals (Co, Fe, Cu, Zn, Cd, Pb) or the fractional land cover of cultivated crops, meadow, and herbs indicating land disturbance as potentially promoting biodiversity. However, correlation between metal-and land-cover trends prevented concluding which of these two covariate types positively affected biodiversity. Because historical aqueous metal concentrations-inferred from solid-water partitioning-approached experimental toxicity thresholds for freshwater algae, positive effects of metal mining on biodiversity are unlikely. Instead, the positive relationship between biodiversity and historical land-cover change can be explained by the increasing proportion of opportunistic species when anthropogenic disturbance intensifies. Our analysis illustrates that focusing on the direct toxic effects of metals alone may yield inaccurate environmental assessments on time scales relevant for biodiversity conservation.

  • 304.
    Deininger, Anne
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Anthropogenic activities are increasing inorganic nitrogen (N) loadings to lakes in the northern hemisphere. In many boreal lakes phytoplankton are N limited, wherefore enhanced N input may affect the productivity of pelagic food webs. Simultaneously, global change causes increased inflows of terrestrial dissolved organic carbon (DOC) to boreal lakes. Between clear and humic lakes, whole lake primary and consumer production naturally differs. However, research is inconclusive as to what controls pelagic production in these lakes. Further, it is unclear how DOC affects the response of the pelagic food web to enhanced inorganic N availability. The overarching goal of this thesis was to study the effects of inorganic N and organic C for pelagic food webs in boreal lakes. In the thesis, I first identified the main drivers of pelagic production during summer in eight non-manipulated Swedish boreal lakes with naturally low or high DOC. Then I investigated how increased N availability affects the pelagic food chain, and how the response differs with DOC. Therefore, whole lake inorganic N fertilization experiments were conducted in six Swedish boreal lakes across a DOC gradient (low, medium, high) divided into three lake pairs (control, N enriched) with one reference and two impact years. In each lake, I also investigated the response of zooplankton growth using in situ mesocosm experiments excluding planktivores. I found that humic boreal lakes had lower phytoplankton production and biomass than clear water lakes. Further, phytoplankton community composition and food quality differed with DOC. However, high DOC did not reduce pelagic energy mobilization or zooplankton biomass, but promoted a higher dominance of cladoceran relative to copepod species. N addition clearly enhanced phytoplankton biomass and production in the experimental lakes. However, this stimulating N effect decreased with DOC as caused by light limitation. Further, the newly available phytoplankton energy derived from N addition was not efficiently transferred to zooplankton, which indicates a mismatch between producer energy supply and consumer energy use. Indeed, the mesocosm experiment revealed that decreased food quality of phytoplankton in response to N addition resulted in reduced food web performance, especially in clearer lakes. In humic lakes, zooplankton production and food web efficiency were clearly more resilient to N addition. In summary, my thesis suggests that any change in the landscape that enhances inorganic N availability will especially affect pelagic food webs in clear water lakes. In contrast, brownification will result in more lakes being resilient to eutrophication caused by enhanced N deposition.

  • 305.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Faithfull, Carolyn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nitrogen effects on the pelagic food web are modified by dissolved organic carbon2017Inngår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 184, nr 4, s. 901-916Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Global environmental change has altered the nitrogen (N) cycle and enhanced terrestrial dissolved organic carbon (DOC) loadings to northern boreal lakes. However, it is still unclear how enhanced N availability affects pelagic food web efficiency (FWE) and crustacean zooplankton growth in N limited boreal lakes. Here, we performed in situ mesocosm experiments in six unproductive boreal Swedish lakes, paired across a DOC gradient, with one lake in each pair fertilized with N (2011: reference year; 2012, 2013: impact years). We assessed how zooplankton growth and FWE were affected by changes in pelagic energy mobilization (PEM), food chain length (phytoplankton versus bacterial production based food chain, i.e. PP:BP), and food quality (seston stoichiometry) in response to N fertilization. Although PP, PEM and PP:BP increased in low and medium DOC lakes after N fertilization, consumer growth and FWE were reduced, especially at low DOC-potentially due to reduced phytoplankton food quality [increased C: phosphorus (P); N:P]. At high DOC, N fertilization caused modest increases in PP and PEM, with marginal changes in PP:BP and phytoplankton food quality, which, combined, led to a slight increase in zooplankton growth and FWE. Consequently, at low DOC (<12 mg L-1), increased N availability lowers FWE due to mismatches in food quality demand and supply, whereas at high DOC this mismatch does not occur, and zooplankton production and FWE may increase. We conclude that the lake DOC level is critical for predicting the effects of enhanced inorganic N availability on pelagic productivity in boreal lakes.

  • 306.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Faithfull, Carolyn L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nitrogen effects on aquatic food web efficiency in the pelagic zone of unproductive lakes along a gradient of dissolved organic carbonManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Atmospheric nitrogen (N) deposition and terrestrial dissolved organic carbon (DOC) loadings are increasing in northern boreal lakes. However, consequences of increased N availability on food web efficiency (FWE) and consumer growth in N limited unproductive boreal lakes are unclear. Here, we performed in situ mesocosm experiments in late summer (2011; 2013) in six unproductive boreal Swedish lakes, paired across a DOC gradient, with one lake in each pair fertilized with N (2011: reference year; 2012, 2013: impact years). We assessed how zooplankton growth and FWE were affected by changes in pelagic energy mobilization (PEM), food chain length (PP:BP, i.e. phytoplankton: bacterial production ratio), and food quality (seston stoichiometry) in response to N fertilization. Although PP, PEM and PP:BP increased in low and medium DOC lakes after N fertilization, consumer growth and FWE in the low DOC lake were reduced, potentially due to a reduction in phytoplankton food quality (increased C:P; N:P). At high DOC, N fertilization caused modest increases in PP and PEM, with marginal changes in PP:BP and phytoplankton food quality, which combined led to a slight increase in zooplankton growth and FWE. We conclude that the background lake DOC level is critical in order to infer effects of enhanced inorganic N availability on pelagic productivity and FWE. In clear lakes increased N deposition will decrease FWE due to mismatches in food quality demand and supply. In humic lakes this mismatch will not occur, wherefore and zooplankton production and FWE will increase slightly following enhanced N deposition.

  • 307.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Faithfull, Carolyn L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Phytoplankton response to whole lake inorganic N fertilization along a gradient in dissolved organic carbon2017Inngår i: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 98, nr 4, s. 982-994Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Global change has increased inorganic nitrogen (N) and dissolved organic carbon (DOC; i.e. ‘browning’) inputs to northern hemisphere boreal lakes. However, we do not know how phytoplankton in nutrient poor lake ecosystems of different DOC concentration respond to increased N availability. Here, we monitored changes in phytoplankton production, biomass and community composition in response to whole lake inorganic N fertilization in six boreal unproductive Swedish lakes divided into three lake pairs (control, N enriched) at three DOC levels (low, medium, high), with one reference year (2011) and two impact years (2012, 2013). We found that phytoplankton biomass and production decreased with DOC concentration before N fertilization. Further, phytoplankton community composition also differed with respect to DOC, with a dominance of non-flagellated autotrophs at low DOC towards an increasing dominance of flagellated autotrophs with increased lake DOC concentration. The N fertilization increased phytoplankton biomass and production in all lakes, but did not affect phytoplankton community composition. However, the net response in biomass and production to N fertilization declined with increasing DOC, implying that the lake DOC concentration is critical in order to infer phytoplankton responses to N fertilization, and that the system switches from being primarily nutrient limited to becoming increasingly light limited with increased DOC concentration. In conclusion, our results show that browning will reduce phytoplankton production and biomass and influence phytoplankton community composition, whereas increased inorganic N loadings from deposition, forestry or other land use will primarily enhance phytoplankton biomass and production. Together, any change in the landscape that enhances inorganic N availability will increase phytoplankton production and biomass, but the positive effects of N will be much weaker or even neutralized in browner lakes as caused by light limitation.

  • 308.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Faithfull, Carolyn L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Oceanography, University of Hawai'i, Honolulu, USA.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaus, Marcus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Pelagic food web response to whole lake N fertilization2017Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 62, nr 4, s. 1498-1511Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anthropogenic activities are increasing inorganic nitrogen (N) loadings to unproductive boreal lakes. In many of these lakes phytoplankton are N limited, consequently N fertilization may affect ecosystem productivity and consumer resource use. Here, we conducted whole lake inorganic N fertilization experiments with six small N limited unproductive boreal lakes (three control and three N enriched) in an area receiving low N deposition with one reference and two impact years. Our aim was to assess the effects of N fertilization on pelagic biomass production and consumer resource use. We found that phytoplankton primary production (PP) and biomass, and the PP: bacterioplankton production ratio increased after fertilization. As expected, the relative contribution of phytoplankton derived resources (autochthony) that supported the crustacean zooplankton community increased. Yet, the response in the consumer community was modest with autochthony only increasing in one of the three major zooplankton groups and with no effect on zooplankton biomass. In conclusion, our findings imply that newly available phytoplankton energy derived from N fertilization was not efficiently transferred up to zooplankton, indicating a mismatch between producer energy supply and consumer energy use with potential accumulation of phytoplankton biomass as the result.

  • 309.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Faithfull, Carolyn L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Lange, K.
    Bayer, T.
    Vidussi, F.
    Liess, Antonia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Simulated terrestrial runoff triggered a phytoplankton succession and changed seston stoichiometry in coastal lagoon mesocosms2016Inngår i: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 119, s. 40-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change scenarios predict intensified terrestrial storm runoff, providing coastal ecosystems with large nutrient pulses and increased turbidity, with unknown consequences for the phytoplankton community. We conducted a 12-day mesocosm experiment in the Mediterranean Thau Lagoon (France), adding soil (simulated runoff) and fish (different food webs) in a 2 x 2 full factorial design and monitored phytoplankton composition, shade adaptation and stoichiometry. Diatoms (Chaetoceros) increased fourfold immediately after soil addition, prymnesiophytes and dinoflagellates peaked after six- and 12 days, respectively. Soil induced no phytoplanlcton shade adaptation. Fish reduced the positive soil effect on dinoflagellates (Scripsiella, Glenodinium), and diatom abundance in general. Phytoplankton community composition drove seston stoichiometry. In conclusion, pulsed terrestrial runoff can cause rapid, low quality (high carbon: nutrient) diatom blooms. However, bloom duration may be short and reduced in magnitude by fish. Thus, climate change may shift shallow coastal ecosystems towards famine or feast dynamics.

  • 310.
    Deininger, Anne
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Norwegian Institute for Water Research (NIVA), Oslo, Norway; Department of Natural Sciences, University of Agder, Kristiansand, Norway.
    Jonsson, A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Karlsson, J.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bergström, A-K.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Pelagic food webs of humic lakes show low short-term response to forest harvesting2019Inngår i: Ecological Applications, ISSN 1051-0761, E-ISSN 1939-5582, Vol. 29, nr 1, artikkel-id UNSP e01813Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Forest harvest in the boreal zone can increase the input of terrestrial materials such as dissolved organic carbon (DOC) and nitrate (NO3-) into nearby aquatic ecosystems, with potential effects on phytoplankton growth through enhanced nutrient (i.e., positive) or reduced light availability (i.e., negative), which may affect ecosystem productivity and consumer resource use. Here, we conducted forest clear-cutting experiments in the catchments of four small, humic, and nitrogen-limited unproductive boreal lakes (two controls and two clear-cut, 18% and 44% of area cut) with one reference and two impact years. Our aim was to assess the effects of forest clear-cutting on pelagic biomass production and consumer resource use. We found that pelagic biomass production did not change after two years of forest clear-cutting: Pelagic primary and bacterial production (PP, BP), PP:BP ratio, chl a, and seston carbon (seston C) were unaffected by clear-cutting; neither did tree harvest affect seston stoichiometry (i.e., N:phosphorus [P], C:P) nor induce changes in zooplankton resource use, biomass, or community composition. In conclusion, our findings suggest that pelagic food webs of humic lakes (DOC > 15 mg/L) might be resilient to a moderate form of forest clear-cutting, at least two years after tree removal, before mechanical site preparation (e.g., mounding, plowing) and when leaving buffer strips along lakes and incoming streams. Thus, pelagic food web responses to forest clear-cutting might not be universal, but could depend on factors such as the time scale, share of catchment logged, and the forest practices involved, including the application of buffer strips and site preparation.

  • 311. Delcloo, Andy
    et al.
    Andersson, Camilla
    Forsberg, Bertil
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Nawrot, Tim
    Valari, Myrto
    ACCEPTED: An Assessment of Changing Conditions, Environmental Policies, Time-Activities, Exposure and Disease2014Inngår i: Air Pollution Modeling and its Application XXIII / [ed] Douw Steyn, Rohit Mathur, SPRINGER-VERLAG BERLIN , 2014, s. 55-59Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Changes in urban design and traffic policy, demography, climate and associated adaptation, mitigation measures and environmental policies are likely to modify both outdoor and indoor air quality and therefore public health. The project aims to improve our understanding of future exposure situations and their impact on health, from an interdisciplinary approach. This will be achieved by using various state-of-the-art atmospheric models, measurements, epidemiological studies and reviews. To assess population full exposure, an integrated view accounting both for indoor and outdoor air pollution as well as for population time activity data will be developed. New dose-response functions will be estimated between health outcome, air pollution and temperature in order to better estimate the effects on the foetus and young children. Ultimately, scenarios of future urban climate and air quality will be simulated, combining future exposure scenarios, population scenarios and exposure-response functions to describe the effects of different trends and relevant policies on relative risk and burden of illness attributed to urban pollutants and their interactions with extreme temperatures. Also the mitigation strategies that can be used to reduce urbanization and climate change effects on the local urban meteorology and air quality will be assessed. With applications in several large European cities, the project will study the impact of several alternative adaptation scenarios on urban air quality and human health to a mid-century horizon (2030-2060) accounting for the effects of a changing urban climate. Scenario-based health impact assessments will combine exposure information from climate models, emission scenarios, policy evaluation studies and concentration calculations with exposure-response functions from epidemiological studies of vulnerable groups within the project and previously published functions for mortality and hospital admissions. The effects of socioeconomic and demographic trends will be discussed, the predicted health impacts and benefits associated with different interventions and policies and other urban changes will be described.

  • 312.
    Demiroglu, Osman Cenk
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för geografi och ekonomisk historia, Kulturgeografi.
    Akbas, Abdullah
    Turp, M. Tufan
    Ozturk, Tugba
    An, Nazan
    Kurnaz, Mehmet Levent
    Case study Turkey: climate change and coastal tourism: impacts of climate change on the Turquoise coast2017Inngår i: Global climate change and coastal tourism: recognizing problems, managing solutions and future expectations / [ed] Andrew Jones and Michael Phillips, CABI Publishing, 2017, s. 247-262Kapittel i bok, del av antologi (Fagfellevurdert)
  • 313.
    Demiroglu, Osman Cenk
    et al.
    Department of Tourism and Hotel Management, Istanbul Bilgi University, Istanbul 34060, Turkey; Department of Tourism Administration, Bogazici University, Istanbul 34342, Turkey; Center for Climate Change and Policy Studies, Bogazici University, Istanbul 34342, Turkey.
    Turp, M. Tufan
    Ozturk, Tugba
    Kurnaz, M. Levent
    Impact of climate change on natural snow reliability, snowmaking capacities, and wind conditions of ski resorts in northeast Turkey: a dynamical downscaling approach2016Inngår i: Atmosphere, ISSN 2073-4433, E-ISSN 2073-4433, Vol. 7, nr 4, artikkel-id 52Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many ski resorts worldwide are going through deteriorating snow cover conditions due to anthropogenic warming trends. As the natural and the artificially supported, i.e., technical, snow reliability of ski resorts diminish, the industry approaches a deadlock. For this reason, impact assessment studies have become vital for understanding vulnerability of ski tourism. This study considers three resorts at one of the rapidly emerging ski destinations, Northeast Turkey, for snow reliability analyses. Initially one global circulation model is dynamically downscaled by using the regional climate model RegCM4.4 for 1971-2000 and 2021-2050 periods along the RCP4.5 greenhouse gas concentration pathway. Next, the projected climate outputs are converted into indicators of natural snow reliability, snowmaking capacity, and wind conditions. The results show an overall decline in the frequencies of naturally snow reliable days and snowmaking capacities between the two periods. Despite the decrease, only the lower altitudes of one ski resort would face the risk of losing natural snow reliability and snowmaking could still compensate for forming the base layer before the critical New Year's week. On the other hand, adverse high wind conditions improve as to reduce the number of lift closure days at all resorts. Overall, this particular region seems to be relatively resilient against climate change.

  • 314. Demuzere, M
    et al.
    Orru, K
    Heidrich, O
    Olazabal, E
    Geneletti, D
    Orru, Hans
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin. University of Tartu, Department of Public Health, Tartu, Estonia.
    Bhave, AG
    Mittal, N
    Feliu, E
    Faehnle, M
    Mitigating and adapting to climate change: multi-functional and multi-scale assessment of green urban infrastructure2014Inngår i: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 146, s. 107-115Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to develop climate resilient urban areas and reduce emissions, several opportunities exist starting from conscious planning and design of green (and blue) spaces in these landscapes. Green urban infrastructure has been regarded as beneficial, e.g. by balancing water flows, providing thermal comfort. This article explores the existing evidence on the contribution of green spaces to climate change mitigation and adaptation services. We suggest a framework of ecosystem services for systematizing the evidence on the provision of bio-physical benefits (e.g. CO2 sequestration) as well as social and psychological benefits (e.g. improved health) that enable coping with (adaptation) or reducing the adverse effects (mitigation) of climate change. The multi-functional and multi-scale nature of green urban infrastructure complicates the categorization of services and benefits, since in reality the interactions between various benefits are manifold and appear on different scales. We will show the relevance of the benefits from green urban infrastructures on three spatial scales (i.e. city, neighborhood and site specific scales). We will further report on co-benefits and trade-offs between the various services indicating that a benefit could in turn be detrimental in relation to other functions. The manuscript identifies avenues for further research on the role of green urban infrastructure, in different types of cities, climates and social contexts. Our systematic understanding of the bio-physical and social processes defining various services allows targeting stressors that may hamper the provision of green urban infrastructure services in individual behavior as well as in wider planning and environmental management in urban areas.

  • 315.
    Denfeld, Blaize A.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Baulch, Helen M.
    del Giorgio, Paul A.
    Hampton, Stephanie E.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Climate Impacts Research Centre, Umeå University, Umeå, Sweden.
    A synthesis of carbon dioxide and methane dynamics during the ice-covered period of northern lakes2018Inngår i: Limnology and Oceanography Letters, ISSN 2378-2242, Vol. 3, nr 3, s. 117-131Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ice‐covered period on lakes in the northern hemisphere has often been neglected or assumed to have less importance relative to the open water season. However, recent studies challenge this convention, suggesting that the winter period is more dynamic than previously thought. In this review, we synthesize the current understanding of under‐ice carbon dioxide (CO2) and methane (CH4) dynamics, highlighting the annual importance of CO2 and CH4 emissions from lakes at ice‐melt. We compiled data from 25 studies that showed that the ice‐melt period represents 17% and 27% of the annual CO2 and CH4 emissions, respectively. We also found evidence that the magnitude and type of emission (i.e., CO2 and CH4) varies with characteristics of lakes including geographic location, lake morphometry, and physicochemical conditions. The scarcity of winter and spring carbon data from northern lakes represents a major gap in our understanding of annual budgets in these lakes and calls for future research during this key period.

  • 316.
    Denfeld, Blaize A.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaus, Marcus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Laudon, Hjalmar
    Swedish University of Agricultural Sciences.
    Sponseller, Ryan A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Carbon Dioxide and Methane Dynamics in a Small Boreal Lake During Winter and Spring Melt Events2018Inngår i: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, E-ISSN 2169-8961, Vol. 123, nr 8, s. 2527-2540Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In seasonally ice‐covered lakes, carbon dioxide (CO2) and methane (CH4) emission at ice‐off can account for a significant fraction of the annual budget. Yet knowledge of the mechanisms controlling below lake‐ice carbon (C) dynamics and subsequent CO2 and CH4 emissions at ice‐off is limited. To understand the control of below ice C dynamics, and C emissions in spring, we measured spatial variation in CO2, CH4, and dissolved inorganic and organic carbon from ice‐on to ice‐off, in a small boreal lake during a winter with sporadic melting events. Winter melt events were associated with decreased surface water DOC in the forest‐dominated basin and increased surface water CH4 in the mire‐dominated basin. At the whole‐lake scale, CH4 accumulated below ice throughout the winter, whereas CO2 accumulation was greatest in early winter. Mass‐balance estimates suggest that, in addition to the CO2 and CH4 accumulated during winter, external inputs of CO2 and CH4 and internal processing during ice‐melt could represent significant sources of C gas emissions during ice‐off. Moreover, internal processing of CO2 and CH4 worked in opposition, with production of CO2 and oxidation of CH4 dominating at ice‐off. These findings have important implications for how small boreal lakes will respond to warmer winters in the future; increased winter melt events will likely increase external inputs below ice and thus alter the extent and timing of CO2 and CH4 emissions to the atmosphere at ice‐off.

  • 317.
    Diehl, Sebastian
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Biology II, Ludwig-Maximilians-University, Germany.
    Berger, Stella A.
    Soissons, Quentin
    Giling, Darren P.
    Stibor, Herwig
    An experimental demonstration of the critical depth principle2015Inngår i: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 72, nr 6, s. 2051-2060Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sverdrup's critical depth hypothesis, which has had an almost canonical status in biological oceanography, has recently been challenged as a universal explanation for the formation of oceanic spring blooms, and several alternative hypotheses have been proposed. Arguments pro and contra alternative explanations have so far relied on theoretical considerations and purely observational data. In this paper, we propose that mesocosm experiments with natural plankton communities could make important contributions to the resolution of the issue. We first briefly review the foundations of the critical depth concept and derive an approximate relationship that relates optically scaled critical depth (="critical optical depth", i.e. the product of the light attenuation coefficient and the critical depth) to light-dependent phytoplankton production in the mixed surface layer. We describe how this relationship can be used to scale experimental mesocosms such that they reproduce ambient light conditions of natural water columns from the surface down to the critical depth and beyond. We illustrate the power of the approach with a mesocosm study in which we experimentally controlled the onset of the spring bloom of a lake plankton community through the manipulation of optically scaled mixed-layer depth. This experiment may be the first experimental demonstration of the critical depth principle acting on a natural plankton community. Compensation light intensity (=minimum average mixed-layer light intensity required to trigger a bloom of the ambient plankton community) could be constrained to be somewhat above 3.2 moles PAR m(-2) d(-1), corresponding to a critical optical depth of 10.5. We compare these numbers to estimates from marine systems and end with a discussion of how experiments could be designed to (i) more accurately determine the critical depth in a given system and (ii) resolve among competing hypotheses for vernal bloom onset.

  • 318. Dixon, P. Grady
    et al.
    Allen, Michael
    Gosling, Simon N.
    Hondula, David M.
    Ingole, Vijendra
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Epidemiologi och global hälsa. Vadu Rural Health Program, KEM Hospital Research Centre.
    Lucas, Rebekah
    Vanos, Jennifer
    Perspectives on the Synoptic Climate Classification and its Role in Interdisciplinary Research2016Inngår i: Geography Compass, ISSN 1749-8198, E-ISSN 1749-8198, Vol. 10, nr 4, s. 147-164Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Synoptic climatology has a long history of research where weather data are aggregated and composited to gain a better understanding of atmospheric effects on non-atmospheric variables. This has resulted in an applied scientific discipline that yields methods and tools designed for applications across disciplinary boundaries. The spatial synoptic classification (SSC) is an example of such a tool that helps researchers bridge methodological gaps between disciplines, especially those studying weather effects on human health. The SSC has been applied in several multi-discipline projects, and it appears that there is ample opportunity for growth into new topical areas. Likewise, there is opportunity for the SSC network to be expanded across the globe, especially into mid-latitude locations in the Southern Hemisphere. There is some question of the utility of the SSC in tropical locations, but such decisions must be based on the actual weather data from individual locations. Despite all of the strengths and potential uses of the SSC, there are some research problems, some locations, and some datasets for which it is not suitable. Nevertheless, the success of the SSC as a cross-disciplinary method is noteworthy because it has become a catalyst for collaboration.

  • 319.
    Do, Lan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    New tools for sample preparation and instrumental analysis of dioxins in environmental samples2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of structurally related chlorinated aromatic hydrocarbons, are of high concern due to their global distribution and extreme toxicity. Since they occur at very low levels, their analysis is complex, challenging and hence there is a need for efficient, reliable and rapid alternative analytical methods. Developing such methods was the aim of the project this thesis is based upon.

    During the first years of the project the focus was on the first parts of the analytical chain (extraction and clean-up). A selective pressurized liquid extraction (SPLE) procedure was developed, involving in-cell clean-up to remove bulk co-extracted matrix components from sample extracts. It was further streamlined by employing a modular pressurized liquid extraction (M-PLE) system, which simultaneously extracts, cleans up and isolates planar PCDD/Fs in a single step. Both methods were validated using a wide range of soil, sediment and sludge reference materials. Using dichloromethane/n-heptane (DCM/Hp; 1/1, v/v) as a solvent, results statistically equivalent to or higher than the reference values were obtained, while an alternative, less harmful non-chlorinated solvent mixture - diethyl ether/n-heptane (DEE/Hp; 1/2, v/v) – yielded data equivalent to those values.

    Later, the focus of the work shifted to the final instrumental analysis. Six gas chromatography (GC) phases were evaluated with respect to their chromatographic separation of not just the 17 most toxic congeners (2,3,7,8-substituted PCDD/Fs), but all 136 tetra- to octaCDD/Fs. Three novel ionic liquid columns performed much better than previously tested commercially available columns. Supelco SLB-IL61 offered the best overall performance, successfully resolving 106 out of the 136 compounds, and 16 out of the 17 2,3,7,8-substituted PCDD/Fs. Another ionic liquid (SLB-IL111) column provided complementary separation. Together, the two columns separated 128 congeners. The work also included characterization of 22 GC columns’ selectivity and solute-stationary phase interactions. The selectivities were mapped using Principal Component Analysis (PCA) of all 136 PCDD/F’s retention times on the columns, while the interactions were probed by analyzing both the retention times and the substances’ physicochemical properties.

  • 320.
    Do, Thanh Lan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Lundstedt, Staffan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Haglund, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Selective pressurized liquid extraction of PCDD/Fs in soil: Optimization using experimental design2010Konferansepaper (Fagfellevurdert)
  • 321. D'Odorico, Paolo
    et al.
    Davis, Kyle Frankel
    Rosa, Lorenzo
    Carr, Joel A.
    Chiarelli, Davide
    Dell'Angelo, Jampel
    Gephart, Jessica
    MacDonald, Graham K.
    Seekell, David A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Suweis, Samir
    Rulli, Maria Cristina
    The global Food-Energy-Water Nexus2018Inngår i: Reviews of geophysics, ISSN 8755-1209, E-ISSN 1944-9208, Vol. 56, nr 3, s. 456-531Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Water availability is a major factor constraining humanity's ability to meet the future food and energy needs of a growing and increasingly affluent human population. Water plays an important role in the production of energy, including renewable energy sources and the extraction of unconventional fossil fuels that are expected to become important players in future energy security. The emergent competition for water between the food and energy systems is increasingly recognized in the concept of the "food-energy-water nexus." The nexus between food and water is made even more complex by the globalization of agriculture and rapid growth in food trade, which results in a massive virtual transfer of water among regions and plays an important role in the food and water security of some regions. This review explores multiple components of the food-energy-water nexus and highlights possible approaches that could be used to meet food and energy security with the limited renewable water resources of the planet. Despite clear tensions inherent in meeting the growing and changing demand for food and energy in the 21st century, the inherent linkages among food, water, and energy systems can offer an opportunity for synergistic strategies aimed at resilient food, water, and energy security, such as the circular economy.

  • 322.
    Drotz, Marcus K.
    et al.
    Lake Vänern Museum Nat & Cultural Hist, S-53154 Lidköping Vid Vänern, Sweden.
    Brodin, Tomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Berggren, Matz
    University of Gothenburg, Inst Marine Ecology Kristineberg, SE-45034 Fiskebackskil, Sweden.
    Distribution patterns of the Chinese mitten crab (Eriocheir sinensis H. Milne Edwards, 1853) in Lake Vanern, Sweden2012Inngår i: AQUAT INVASIONS, ISSN 1798-6540, Vol. 7, nr 2, s. 243-249Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The catadromous Chinese mitten crab (CMC), Eriocheir sinensis is well known for its extensive invasion routes across the world. However, little is known about both adult and juvenile behaviour after they arrive to a new region. Particularly if the CMC has utilised freight ship ballast tanks as its invasion vector to new freshwater areas like coastal connected larger lakes. The Swedish Lake Vanern, Europe's third largest freshwater lake, offers a suitable study area since only a handful of CMC had been reported between its first record in 1954 and 2004. Hence, the increased catch of of CMC in the mid 2000s was unexpected and provided a rare opportunity to study the initial phase of a biological invasion. Fortunately local fishermen have traditionally, since the mid 1970s, utilised large stationary fish trap nets, evenly distributed from the inlet to the harbour of Lidkoping outward into the main part of the lake. During the peak occurrence in 2005 the traps captured CMC frequently for 90 days starting on August 10. Daily catch increased from September 19th to October 17th. Thereafter the number decreased until November 7th when the last crab was captured. Only one crab out of the 21 caught in the two traps furthest away from the harbour inlet was caught before September 19th. The number of caught CMC differed significantly between the trap nets. Almost half (48.4 %) of all CMC were caught in the two traps closest to the harbour inlet and 41.9% in the second trap-line, consisting of two traps 6 km from the harbour inlet. The remaining crabs were caught in the traps furthest away. Catch pattern from this unique invasion event is discussed in relation to CMC dispersal/migration, invading sample size, behavioural traits and catch efficiency of traps.

  • 323. Du, Xinyu
    et al.
    Yuan, Bo
    Zhou, Yihui
    Zheng, Ziye
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Wu, Yan
    Qiu, Yanling
    Zhao, Jianfu
    Yin, Ge
    Tissue-Specific Accumulation, Sexual Difference, and Maternal Transfer of Chlorinated Paraffins in Black-Spotted Frogs2019Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, nr 9, s. 4739-4746Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The restriction on usage of short-chain chlorinated paraffins (SCCPs) under Stockholm Convention may promote the production and application of medium chain chlorinated paraffins (MCCPs) and long chain chlorinated paraffins (LCCPs) as substitutes. This study focused on the tissue-specific exposure to SCCPs, MCCPs, and LCCPs in black-spotted frog, a prevalent amphibian species in the Yangtze River Delta, China. The total CP concentrations in frog liver, muscle, and egg samples ranged of 35-1200, 6.3-97, and 6.8-300 ng/g wet weight (ww), respectively. Livers and eggs contained primary SCCPs (on average 78%) while MCCPs (43%) together with SCCPs (41%) were dominant in muscles. A significantly negative correlation was observed between hepatosomatic index and CPs concentration in liver (p < 0.01), indicating that CP exposure may lower survival rates of frogs by suppressing the energy storage in liver. Additionally, maternal transfer, an important uptake pathway for CPs, was evaluated for the first time by calculating the ratios of CP levels in eggs to those in their paired liver tissues. The ratio of egg to liver for CP congener groups raised with the increasing of log K-ow values, indicating mother to egg transport of CPs was related to the lipophilicity of the chemicals.

  • 324.
    Dupuis, Johann
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för geografi och ekonomisk historia. IDHEAP, Swiss Graduate School of Public Administration, Université de Lausanne, Switzerland.
    Biesbroek, Robbert
    Comparing apples and oranges: The dependent variable problem in comparing and evaluating climate change adaptation policies2013Inngår i: Global Environmental Change, ISSN 0959-3780, E-ISSN 1872-9495, Vol. 23, nr 6, s. 1476-1487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An increasing number of studies have compared climate change adaptation policies within and between different countries. In this paper we show that these comparative studies suffer from what is known as the "dependent variable problem' - the indistinctness of the phenomenon that is being measured, and disagreement on its scope and boundaries. This problem has been signaled in other scientific fields where it proved to hamper meaningful comparisons and policy evaluations, transnational learning, and policy transfer. This paper aims to raise consciousness of the dependent variable problem in comparative studies on climate change adaptation policy by exploring its origins and proposes ways to deal with it. Three main sources of the problem are discussed: (1) conceptual indistinctness of adaptation policy and the heterogeneity and lack of consistency of what is being compared between cases. (2) Inadequate research designs to compare cases. (3) Unclear indicators and explanatory variables to compare across cases. We propose a way to operationalize the concept of adaptation policy, provide a narrower description of the research designs for policy change or outcomes analysis, and finally discuss possible measurements concepts.

  • 325. Durig, Wiebke
    et al.
    Tröger, Rikard
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Rybacka, Aleksandra
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Fischer, Stellan
    Wiberg, Karin
    Ahrens, Lutz
    Development of a suspect screening prioritization tool for organic compounds in water and biota2019Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 222, s. 904-912Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A customizable in silico tool (SusTool) for generating high resolution mass spectrometry (HRMS) suspect screening lists, specifically designed for the detection of hazardous organic compounds in various environmental compartments, was created. A database consisting of similar to 32 000 environmentally relevant organic compounds was constructed, including data on their physicochemical properties, environmental fate characteristics, and endocrine disruption potential, along with emissions and quantity indices. Welldefined customized suspect lists were generated by systematic ranking using a scoring and weighting procedure. For demonstration purposes, three suspect screening lists were created, one for water (SLWater) and two for biota covering less (SLBiota Kow<5 ) or more hydrophobic chemicals (SLBiota Kow>3). Scrutiny of overlaps between compounds within these lists and the SusDat database (20 suspect lists comprising similar to 58 000 compounds compiled by the Norman network) showed that approximately half of the compounds in the three suspect lists were also listed in one of the SusDat database lists. This indicates that SusTool is able to include highly relevant emerging pollutants, but also captures other compounds of potential concern that have been less well studied or not yet investigated. Overall, our in silico prioritization approach enables systematic creation of suspect screening lists and provides new opportunities for suspect screening for environmentally relevant compounds. 

  • 326.
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Responses of bryophytes to wood-ash recycling are related to their phylogeny and pH ecology2012Inngår i: Perspectives in plant ecology, evolution and systematics, ISSN 1433-8319, E-ISSN 1618-0437, Vol. 14, nr 1, s. 21-31Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ash generated by the combustion of solid biofuels is increasingly being returned to the fuel’s place of origin (mostly forests). In this way, nutrient depletion and acidification caused by biofuel harvest is counteracted and a waste problem is solved. Concerns about the potential negative effects of ash spreading on forest biodiversity (in particular mosses) have been raised, but little is known. I studied the effects of the application of two types of ash (the most used self-hardened crushed ash including fine particles and a less reactive type, pellets without fine particles) on 28 moss species and 17 liverwort species. In two field experiments, one on transplants of ground-living species and one on wood-inhabiting species in situ, I measured the response during the first two months after ash application. Visible damage (discoloration from green to brown) was assessed for all species and the growth response was measured for 24 ground-living species. The responses to crushed ash were clearly related to the species’ pH ecology and phylogenetic position. The growth of bryophytes associated with acidic conditions (pooled data from 10 species) or considered as being indifferent to pH (4 species) was negatively affected, whereas there was no effect on the growth of bryophytes of non-acidic habitats (10 species). The connection to phylogeny was even clearer. Most taxa responded negatively, but transplants from the moss order Bryales (4 species) and the family Brachytheciaceae (2 species; order Hypnales) grew better when treated with ash. The genera with the clearest negative responses were Sphagnum mosses (5 species), Tetraphis mosses (1 species), Dicranum mosses (6 species), and Barbilophozia liverworts (2 species). The four red-listed wood-inhabiting liverworts studied were not significantly damaged. Concerning ash type, pellets caused smaller effects than crushed ash, both on the positive and negative side. The results show that responses to ash recycling of the bryophyte species included in this study are predictable from their phylogenetic position and/or pH ecology. Further studies are needed to determine the generality of these results and to sort out if phylogeny or current relationship to pH is the primary determinant of the response.

  • 327.
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Slow recovery of bryophyte assemblages in middle-aged boreal forests regrown after clear-cutting2015Inngår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 191, s. 101-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Clear-cutting followed by even-aged forestry is transforming forests around the globe. There is growing concern that considerable parts of the native forest biodiversity will not be able to re-colonize these new stands before the next clear-cutting. The development of species assemblages during the full forestry rotation period must be understood in order to assess the need for management adaptations and to get a basis for their design. Knowledge is accumulating from studies of permanent plots before and shortly after clear-cutting, but for later stages only comparative studies have been published (space-for-time substitutions). In this study, I combined this comparative approach with direct monitoring of the pace of assemblage recovery in boreal stands regrown after clear-cutting half a century ago (treatment stands). I found little re-colonization in assemblages of mosses and liverworts between an initial survey to a resurvey 15 years later in 0.1-ha permanent plots of upland and stream-side forest. The assemblages of the treatment stands were still significantly different from those in matched old control forests that had never been clear-cut. The treatment stands had significantly fewer species of liverworts and of the substrate-based species subgroup "wood or bark", and the six most negatively affected species were liverworts more or less specialized to this substrate. The only significant recovery recorded over the 15 years was for the "rocks or boulders" subgroup in upland stands, probably related to a shadier and moister climate resulting from canopy development. During the inter-survey period, some of the upland treatment stands were thinned. All disfavored subgroups recovered less in thinned than in not thinned upland stands, most likely as a result of a return to lighter and drier microclimates and direct mechanical disturbance. The incomplete and slow recovery halfway into the forestry rotation period calls for action. Adaptation of thinning for conservation has rarely been implemented in boreal forest management, but has a large potential. To facilitate re-colonization by disfavored liverworts and mosses growing on wood or bark and/or under shaded and moist conditions, I suggest retention of unlogged patches during thinning and addition of coarse deadwood on the ground in these patches. Such measures would also favor re-colonization of other late-successional species.

  • 328.
    Dynesius, Mats
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Stockholms universitet, Botaniska institutionen.
    Hylander, Kristoffer
    Stockholms universitet, Botaniska institutionen.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    High resilience of bryophyte assemblages in streamside compared to upland forests2009Inngår i: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 90, nr 4, s. 1042-1054Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Landscape heterogeneity causes spatial variation in disturbance regimes and resilience. We asked whether the resilience of bryophyte (liverwort and moss) assemblages to clear-cutting differs between streamside and upland boreal forests in northern Sweden. We hypothesized that bryophyte survival and recolonization rates are higher in streamside areas, thus raising resilience. Conversely, disturbance-intolerant but also invading species should be more frequent here, potentially reducing resilience. In each of 18 sites, we compared two 0.1-ha plots (one streamside and one upland) located in old forest that had never been clear-cut with two matching plots in young stands established after clear-cutting of old forests 30-50 years earlier. We used the magnitude of the difference in assemblages between old and young stands as a measure of change and, therefore, resilience (large difference implying low resilience). Species assemblages were more resilient in streamside than in upland forests. Species composition changed significantly in upland but not in streamside forests. Reductions in species richness were more pronounced in upland forests for total richness and for eight subgroups of species. Two results indicated lower survival/recolonization in upland forests: (1) species had a stronger association with old stands in upland areas, and (2) among species present in both the old streamside and old upland plot in a site, fewer appeared in the young upland than in the corresponding streamside plot. Simultaneously, a higher proportion of species invaded streamside areas; 40 of the 262 species encountered in streamside forests increased their occupancy by two or more sites compared to only two of 134 species in uplands. We suggest that in boreal forests spatial variation in resilience of assemblages of forest organisms intolerant of canopy removal is related to factors governed mainly by topography. More generally, we argue that landscape-scale variation in resilience of assemblages is influenced by spatial variation in (1) stress and resource availability, (2) number of  disturbance intolerant species, and (3) magnitude of environmental changes brought about by a disturbance with a specific intensity. We also suggest that rapid recovery in the short term does not necessarily imply higher long-term ability to return to the pre-disturbance state.

  • 329.
    Dynesius, Mats
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Åström, Marcus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Microclimatic buffering by logging residues and forest edges reduces clear-cutting impacts on forest bryophytes2008Inngår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 11, nr 3, s. 345-354Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Question: The practice of extracting logging residues after clear-cutting for bioenergy purposes is spreading. Logging residues constitute a shelter in clear-cut areas and therefore concerns have been expressed that their removal could make the ground and its vegetation more exposed to extreme micro¬climatic conditions. We asked whether logging residues and forest edges can protect ground-dwelling forest bryophytes from fatal microclimate events following clear-cutting.

    Location: Boreal forests of central Sweden.

    Methods: Using transplants of eight forest floor bryophyte species we experimentally analysed the sheltering effect (less solar radiation and less wind) of logging residues and forest edges in seven clear-cut areas. Transplants were placed in two contrasting positions in each area; near a north-facing forest edge and in the centre of the clear-cut area. In each position, half of the transplants were covered by a layer of spruce branches and the other half was left uncovered. We estimated proportion of apparently living shoots (apparent vitality) and measured radial growth of transplants during one growing season.

    Results: Position in the clear-cut area, but not cover of spruce branches, clearly influenced radial growth. Vitality scores were higher among transplants covered with branches and the lowest apparent vitality was observed in uncovered transplants in the middle of clear-cut areas. The change in area of apparently liv¬ing shoots during the course of the experiment (growth minus mortality) was unaffected by branch cover close to the edge but positively affected in the centre of the clear-cut area. In general, the effect of branch cover on bryophytes was higher in the centre of clear-cut areas. Here, climatic measurements showed that branch cover buffers during periods of extreme microclimates.

    Conclusions: Extraction of logging residues after clear-felling may reduce the survival of some ground-dwelling forest organisms. The additional sheltering provided by branches was unimportant close to forest edges. We suggest smaller clear-cut areas, green-tree retention and other ways to make logged areas shadier and less windy to mitigate the reduced shelter caused by harvest of logging residues.

  • 330. Ecke, Frauke
    et al.
    Christensen, Pernilla
    Rentz, Ralf
    Nilsson, Mats
    Sandström, Per
    Hörnfeldt, Birger
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Vindelfjällens forskningsstation, Ammarnäs, Sweden; Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden .
    Landscape structure and the long-term decline of cyclic grey-sided voles in Fennoscandia2010Inngår i: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 25, nr 4, s. 551-560Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Changes in forest landscape structure have been suggested as a likely contributing factor behind the long-term decline in the numbers of cyclic grey-sided voles (Clethrionomys rufocanus) in northern Fennoscandian lowland regions in contrast to mountain regions due to the absence of forest management in the mountains. This study, for the first time, formally explored landscape structure in 29 lowland (LF) and 14 mountain forest (MF) landscapes (each 2.5 x 2.5 km) in northern Sweden, and related the results to the cumulated spring trapping index of the grey-sided vole in 2002-2006. The grey-sided vole showed striking contrasts in dynamics close in space and time. The MF landscapes were characterized by larger patches and less fragmentation of preferred forest types. The grey-sided vole was trapped in all of 14 analyzed MF landscapes but only in three out of 29 of the LF landscapes. MF and LF landscapes with grey-sided vole occurrence were characterized by similar focal forest patch size (mean 357 ha, minimum 82 ha and mean 360 ha, minimum 79 ha, respectively). In contrast, these MF compared to the LF landscapes were characterized by larger patches of preferred forest types and less fragmented preferred forest types and by a lower proportion of clear-cut areas. The present results suggest that landscape structure is important for the abundance of grey-sided voles in both regions. However, in the mountains the change from more or less seasonal dynamics to high-amplitude cycles between the mid 1990s and 2000s cannot be explained by changes in landscape structure.

  • 331. Ecke, Frauke
    et al.
    Singh, Navinder J.
    Arnemo, Jon M.
    Bignert, Anders
    Helander, Björn
    Berglund, Åsa M. M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Borg, Hans
    Bröjer, Caroline
    Holm, Karin
    Lanzone, Michael
    Miller, Tricia
    Nordström, Åke
    Räikkönen, Jannikke
    Rodushkin, Ilia
    Ågren, Erik
    Hörnfeldt, Birger
    Sublethal Lead Exposure Alters Movement Behavior in Free-Ranging Golden Eagles2017Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, nr 10, s. 5729-5736Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lead poisoning of animals due to ingestion of fragments from lead-based ammunition in carcasses and offal of shot wildlife is acknowledged globally and raises great concerns about potential behavioral effects leading to increased mortality risks. Lead levels in blood were correlated with progress of the moose hunting season. Based on analyses of tracking data, we found that even sublethal lead concentrations in blood (25 ppb, wet weight), can likely negatively affect movement behavior (flight height and movement rate) of free ranging scavenging Golden Eagles (Aquila chrysaetos). Lead levels in liver of recovered post-mortem analyzed eagles suggested that sublethal exposure increases the risk of mortality in eagles. Such adverse effects on animals are probably common worldwide and across species, where game hunting with lead-based ammunition is widespread. Our study highlights lead exposure as a considerably more serious threat to wildlife conservation than previously realized and suggests implementation of bans of lead ammunition for hunting.

  • 332.
    Eckerberg, Katarina
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Bjärstig, Therese
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Zachrisson, Anna
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Incentives for collaborative governance: top-down and bottom-up initiatives in the Swedish mountain region2015Inngår i: Mountain Research and Development Journal, ISSN 0276-4741, E-ISSN 1994-7151, Vol. 35, nr 3, s. 289-298Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Governance collaborations between public and private partners are increasingly used to promote sustainable mountain development, yet information is limited on their nature and precise extent. This article analyzes collaboration on environment and natural resource management in Swedish mountain communities to critically assess the kinds of issues these efforts address, how they evolve, who leads them, and what functional patterns they exhibit based on Margerum's (2008) typology of action, organizational, and policy collaboration. Based on official documents, interviews, and the records of 245 collaborative projects, we explore the role of the state, how perceptions of policy failure may inspire collaboration, and the opportunities that European Union funds have created. Bottom-up collaborations, most of which are relatively recent, usually have an action and sometimes an organizational function. Top-down collaborations, however, are usually organizational or policy oriented. Our findings suggest that top-down and bottom-up collaborations are complementary in situations with considerable conflict over time and where public policies have partly failed, such as for nature protection and reindeer grazing. In less contested areas, such as rural development, improving tracks and access, recreation, and fishing, there is more bottom-up, action-oriented collaboration. State support, especially in the form of funding, is central to explaining the emergence of bottom-up action collaboration. Our findings show that the state both initiates and coordinates policy networks and retains a great deal of power over the nature and functioning of collaborative governance. A practical consequence is that there is great overlap—aggravated by sectorized approaches—that creates a heavy workload for some regional partners.

  • 333.
    Eckerberg, Katarina
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Larsson, Magnus
    Umeå universitet, Samhällsvetenskapliga fakulteten, Sociologiska institutionen.
    Miljand, Matilda
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Knowledge, policy, and expertise: the UK Royal Commission on Environmental Pollution 1970-2011, by Susan Owens, Oxford, Oxford University Press, 20152016Inngår i: Environmental Politics, ISSN 0964-4016, E-ISSN 1743-8934, Vol. 25, nr 4, s. 761-763Artikkel, omtale (Fagfellevurdert)
  • 334.
    Eckerberg, Katarina
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Nilsson, Måns
    Gerger-Swartling, Åsa
    Söderberg, Charlotta
    Umeå universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen.
    Institutional analysis of energy and agriculture2007Inngår i: Environmental policy integration in practice: shaping institutions for learning / [ed] Måns Nilsson och Katarina Eckerberg, London: Earthscan , 2007, s. 111-136Kapittel i bok, del av antologi (Fagfellevurdert)
  • 335.
    Edin, Malin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Miljöpåverkan av äggproduktion: En jämförelse mellan Lilluns ägg och andra svenska äggproducenter2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    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.

  • 336.
    Edo Gimenez, Mar
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Skoglund, Nils
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik. Energy Engineering, Department of Engineering Sciences & Mathematics, Luleå University of Technology, Luleå, Sweden.
    Gao, Qiuju
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per-Erik
    Jansson, Stina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Fate of metals and emissions of organic pollutants from torrefaction of waste wood, MSW, and RDF2017Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 68, s. 646-652Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Torrefaction of municipal solid waste (MSW), refuse-derived fuel (RDF), and demolition and construction wood (DC) was performed at 220°C and a residence time of 90 min in a bench-scale reactor. The levels of toxic polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) contained in emission from the torrefaction process were evaluated. In addition, main ash-forming elements and trace metals in the raw feedstock and char were determined. The use of MSW in fuel blends with DC resulted in lower PCDD and PCDF emissions after torrefaction, compared with the RDF blends. The migration of chlorine from the feedstock to the gas phase reduces the chlorine content of the char which may reduce the risk of alkali chloride-corrosion in char combustion. However, trace metals catalytically active in the formation of PCDD and PCDF remain in the char, thereby may promote PCDD and PCDF formation during subsequent char combustion for energy recovery; this formation is less extensive than when the feedstock is used.

  • 337.
    Edo, Mar
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Björn, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Persson, Per-Erik
    Jansson, Stina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Assessment of chemical and material contamination in waste wood fuels: a case study ranging over nine years2016Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 49, s. 311-319Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels.

  • 338.
    Edo, Mar
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Ortuño, Núria
    Persson, Per-Erik
    Conesa, Juan A.
    Jansson, Stina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Emissions of toxic pollutants from co-combustion of demolition and construction wood and household waste fuel blends2018Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 203, s. 506-513Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four different types of fuel blends containing demolition and construction wood and household waste were combusted in a small-scale experimental set-up to study the effect of fuel composition on the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), chlorobenzenes (PCBzs), chlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Two woody materials, commercial stemwood (ST) and demolition and construction wood (DC) were selected because of the differences in their persistent organic pollutants (POPs), ash and metals content. For household waste, we used a municipal solid waste (MSW) and a refuse-derived fuel (RDF) from MSW with 5-20 wt% and up to 5 wt% food waste content respectively. No clear effect on the formation of pollutants was observed with different food waste content in the fuel blends tested. Combustion of ST-based fuels was very inefficient which led to high PAH emissions (32 +/- 3.8 mg/kg(fuel)). The use of DC clearly increased the total PCDD and PCDF emissions (71 +/- 26 mu g/kg(fuel)) and had a clear effect on the formation of toxic congeners (210 +/- 87 ng WHO2005-TEQ/kg(fuel)). The high PCDD and PCDF emissions from DC-based fuels can be attributed to the presence of material contaminants such as small pieces of metals or plastics as well as timber treated with chromated copper arsenate preservatives and pentachlorophenol in the DC source. 

  • 339. Eeva, Tapio
    et al.
    Rainio, Miia
    Berglund, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Kanerva, Mirella
    Stauffer, Janina
    Stoewe, Mareike
    Ruuskanen, Suvi
    Experimental manipulation of dietary lead levels in great tit nestlings: limited effects on growth, physiology and survival2014Inngår i: Ecotoxicology, ISSN 0963-9292, E-ISSN 1573-3017, Vol. 23, nr 5, s. 914-928Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We manipulated dietary lead (Pb) levels of nestlings in wild populations of the great tit (Parus major L) to find out if environmentally relevant Pb levels would affect some physiological biomarkers (haematocrit [HT], fecal corticosterone metabolites [CORT], heat shock proteins [HSPs], erythrocyte delta-aminolevulinic acid dehydratase activity [ALAd]), growth (body mass, wing length), phenotype (plumage coloration) or survival of nestlings. The responses to three experimental manipulation (control, low and high: 0, 1 and 4 mu g/g body mass/day) are compared with those in a P. major population breeding in the vicinity of a heavy metal source, a copper smelter. Our Pb supplementation was successful in raising the fecal concentrations to the levels found in polluted environments (high: 8.0 mu g/g d.w.). Despite relatively high range of exposure levels we found only few effects on growth rates or physiology. The lack of blood ALAd inhibition suggests that the circulating Pb levels were generally below the toxic level despite that marked accumulation of Pb in femur (high: 27.8 mu g/g d.w.) was observed. Instead, birds in the metal polluted environment around the smelter showed decreased growth rates, lower HT, higher CORT, less colorful plumage and lower survival probabilities than any of the Pb treated groups. These effects are likely related to decreased food quality/quantity for these insectivorous birds at the smelter site. In general, the responses of nestlings to metal exposure and/or associated resource limitation were not gender specific. One of the stress proteins (HSP60), however, was more strongly induced in Pb exposed males and further studies are needed to explore if this was due to higher accumulation of Pb or higher sensitivity of males. In all, our results emphasize the importance of secondary pollution effects (e.g. via food chain disruption) on reproductive output of birds.

  • 340.
    Ehlers, Ina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Köhler, Iris
    Wieloch, Thomas
    Vlam, Mart
    van der Sleen, Peter
    Groenendijk, Peter
    Grabner, Michael
    Seim, Andrea
    Allen, Kathryn
    Wei, Liang
    Robertson, Iain
    Marshall, John
    Zuidema, Pieter A.
    Schleucher, Jürgen
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Limited suppression of photorespiration by 20th century atmospheric CO2 increase in trees worldwideManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Forests are a key component of the global carbon and hydrological cycle and forest responses to  environmental  drivers  create  important  feedbacks  to  these  cycles.  Photosynthetic efficiency of most forest tree species is strongly limited by photorespiration, a side reaction using O2 instead of CO2 as substrate, leading to a carbon loss for the plant. Photorespiration occurs in all trees and is reduced under elevated CO2 concentrations and increased under elevated temperature. Because the CO2 concentration of the atmosphere has increased in past decades, long-lived trees may have benefited from reduced photorespiration, but the temperature increase would have been a compensating detriment; but direct quantification of long-term changes in metabolic fluxes is lacking. Realistic forecasting of responses of trees and forests to future CO2 and temperature demands quantifying the reduction of photorespiration.  In  twelve  tree  species  from  five  continents,  we  observe  that photorespiration has been reduced by the CO2 increase during the past century, but for most the reduction is smaller than predicted from plant responses in CO2 alone. Comparison with data from a combined CO2 and temperature manipulation experiment shows that the reduced response can be explained by increases in leaf temperatures, which might result directly from increased  air  temperatures  or  indirectly  from  reduced  transpirative  cooling.  These  data suggest that global warming has already inhibited plant fertilization by increasing CO2, and that biomass increases may have been smaller than deduced from measurements of the heavy carbon isotope 13C. Observation of this centennial metabolic shift in tree physiology worldwide provides new insights into forest-climate feedbacks and can be used to improve coupled climate-vegetation models.

  • 341. Ehmke, Mariah D
    et al.
    Shogren, Jason F
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för nationalekonomi. Stroock Professor, Department of Economics and Finance, University of Wyoming, 1000 University Ave, Dept 3985, Laramie, WY 82071, USA.
    Experimental methods for environment and development economics2009Inngår i: Environment and Development Economics, ISSN 1355-770X, E-ISSN 1469-4395, Vol. 14, nr 4, s. 419-456Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Many poor countries remain trapped in a cycle of poverty and environmental degradation. Understanding how people react to existing and proposed solutions most likely can be improved using the methods of experimental economics. Experiments provide researchers a method to test theory, look for patterns of behavior, testbed economic institutions and incentives, and to educate people. Herein we explore how experimental economics has been used and could be used to help guide decision making to increase prosperity without overexploiting the resource base and environmental assets needed for basic survival.

  • 342.
    Ek, A S
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Korsman, T
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    A paleolimnological assessment of the effects of post-1970 reductions of sulfur deposition in Sweden2001Inngår i: Canadian Journal of Fisheries and Aquatic Sciences, ISSN 0706-652X, E-ISSN 1205-7533, Vol. 58, nr 8, s. 1692-1700Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Analysis of diatoms in sediment cores from 10 acidic (pH < 6) lakes in southern Sweden shows that eight of the lakes have acidified after 1950, while two lakes have not significantly acidified. However, since the 1970s, sulfur deposition has decreased by 50%, and lake water chemistry monitored since 1983 shows an initial reversal of acidification. However, the diatom data do not indicate that a general recovery in pH has occurred yet. The diatoms show that a small recovery has occurred in only one lake (pH increase from 4.7 to 4.9). The 10 lakes vary in total organic carbon content from 2 to 17 mg.L-1. According to the diatoms, the lakes with high total organic carbon (>9 mg.L-1) have not acidified as much as the lakes with lower total organic carbon (<7 mg.L-1). We ascribe this difference in response to acid deposition to the buffering capacity of organic acids. Knowledge of the role of organic acids when combined with anthropogenic acid deposition is important in predicting responses to decreasing acid deposition and the time scales required for recovery. Paleolimnological methods are shown here to provide valuable information for these purposes as well as to provide a long-term perspective on lake acidity changes needed for the evaluation of recovery.

  • 343.
    Ek, Kristina
    et al.
    Luleå University of Technology, Economics Unit, Luleå, Sweden.
    Persson, Lars
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Nationalekonomi. Umeå universitet, Samhällsvetenskapliga fakulteten, Centrum för miljö- och naturresursekonomi (CERE).
    Wind farms - where and how to place them?: A choice experiment approach to measure consumer preferences for characteristics of wind farm establishments in Sweden2014Inngår i: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 105, s. 193-203Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper explores preferences among the general public in Sweden for attributes related to the establishment of wind power farms. The method applied is a choice experiment where people are asked to choose between two hypothetical wind farms characterized by different attributes. Five attributes are included in the experiment: (i) type of landscape, (ii) type of ownership, (iii) the degree of local participation in the planning process, (iv) the choice to transfer revenue to the society in a pre-specified way, and (v) a monetary cost in terms of an additional electricity certificate fee. The data are analyzed with multinomial logit, random parameter logit, and latent class models. The results indicate that consumers in Sweden are more likely to accept the higher renewable electricity certificate fee if: (a) wind power farms in areas used for recreational purposes are substantially avoided, (b) the establishment is anchored by whole or partial ownership in the local community and, (c) the locals are involved in the planning and implementation process. Our policy simulation exercise shows that respondents are willing to pay a higher electricity fee corresponding to about 0.6 Euro cents per kWh to avoid wind farms located in the mountainous area and private ownership.

  • 344.
    Ekeberg, Jonas
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. ABB Schweiz AG, Corporate Research, CH-5405 Baden-Dättwil, Switzerland.
    Stasiewicz, Kristof
    Swedish Institute of Space Physics, P.O. Box 537, SE-751 21 Uppsala, Sweden.
    Wannberg, Gudmund
    Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Sergienko, Tima
    Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Eliasson, Lars
    Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Incoherent scatter ion line enhancements and auroral arc-induced Kelvin-Helmholtz turbulence2015Inngår i: Journal of Atmospheric and Solar-Terrestrial Physics, ISSN 1364-6826, E-ISSN 1879-1824, Vol. 122, s. 119-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present two cases of incoherent-scatter ion line enhancements in conjunction with auroral arcs drifting through the radar beam. The up- and downshifted ion line shoulders as well as the spectral region between them are enhanced equally and simultaneously. The power enhancements are one order of magnitude above the thermal level and are concentrated in less than 15 km wide altitude ranges at the ionospheric F region peak. The auroral arc passages are preceded by significantly enhanced ion temperatures in the E region, which are shown to generate high velocity shears. We use a Hall MHD model of velocity shears perpendicular to the geomagnetic field and show that a Kelvin-Helmholtz instability will grow for the two presented cases. We assess the possibility that the subsequently generated low frequency turbulence can explain the observed spectrally uniform ion line power enhancements.

  • 345.
    Ekeberg, Jonas
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Wannberg, Gudmund
    Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Eliasson, Lars
    Swedish Institute of Space Physics, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Häggström, Ingemar
    EISCAT Scientific Association, P.O. Box 812, SE-981 28 Kiruna, Sweden.
    Soliton-induced spectrally uniform ion line power enhancements at the ionospheric F region peak2012Inngår i: Earth Planets and Space, ISSN 1343-8832, E-ISSN 1880-5981, Vol. 64, nr 7, s. 605-611Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present European incoherent scatter (EISCAT) observations of spectrally uniform ion line power enhancements (SUIPE), where the up- and downshifted shoulder and the spectral valley between them are enhanced simultaneously and equally. We have identified 48 cases of this type of ion line enhancements in data from the EISCAT Svalbard radar taken during the International Polar Year (extending from March 2007 to the end of February 2008). The SUIPEs are observed at altitudes between 210 km and 280 km with a standard deviation of 9% of the average occurrence height 230 km. The power enhancements are one order of magnitude above the thermal level. The SUIPEs occur at the ionospheric F region peak with 85% of the cases located within 10 km of the peak. The occurrence shows a clear preference for magnetically disturbed conditions, with the likelihood of occurrence increasing with increasing K index. A majority of the events occur in the magnetic evening to pre-midnight sector.

  • 346.
    Ekelund Nord, Niklas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Fate of four pharmaceuticals in aquatic ecosystems: Investigating the role of UV- light and animal assimilation as dissipation factors2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Pharmaceuticals in the aquatic environment are of concern due to its possible negative consequences for non-target species. Pharmaceuticals can be found in many parts of the environment and especially in the effluent from sewage treatment plants where pharmaceuticals can be found in significant quantities. Therefore it is important to acquire knowledge of the fate of these pharmaceuticals in the aquatic environment. In this study two experimental ponds, one was covered by a tarp to avoid degradation by UV-light, were spiked with ~400 ng/l of diclofenac, diphenhydramine, hydroxyzine and trimethoprim. Water samples were taken regularly during 224 days. Animals from the uncovered pond was sampled weekly for the first 66 days. The aim was to investigate the degradation rate, the importance of UV-light for degradation and the uptake of pharmaceuticals by animals. The results showed that diclofenac and hydroxyzine had the fastest degradation rate and degraded to under 10 ng/l within 14 days and had the shortest calculated half-life of ~5 and ~10 days, respectively. Trimethoprim and diphenhydramine were more recalcitrant towards degradation and still had concentrations at 18 ng/l and ~8 ng/l respectively after 128 days and had half-life of ~23 and 24~days respectively. There were no significant difference between degradation rate between the pond covered with a tarp and the one which received UV-light. Only diphenhydramine and hydroxyzine were assimilated into the sampled animals. This study shows the different behavior of pharmaceuticals concerning their degradation rate and their ability to accumulate into animals. 

  • 347.
    Ekelund Nord, Niklas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Metodundersökning av tre metoder för kvävemätning i en arktisk äng: Jämförelse mellan mätmetoderna extraktion, inkubation och jonbytesmembran (PRS-sond)2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The purpose with this report was to compare three commonly occurring methods for measuring plant available nitrogen in soils. The methods extraction, incubation and Plant root simulator (PRS) probe - an ion exchange membrane (Western Ag Innovations, Inc., Saskatoon, Canada) method were used and comparison between these methods were conducted. A full factorial experiment were set up in northern Finland with the treatments excluding herbivores, warming and fertilization to see how the inorganic nitrogen content in the soil was effected by the treatments. Soil cores were taken and from them a subsample was incubated for 18 days and thereafter analyzed for inorganic N in laboratory. PRS- probes were in the ground for 1 month. It was a strong positive correlation between extracted and incubated samples but no correlation between the PRS- probes and extraction or incubation samples. The PRS- probes showed several significant changes in inorganic N content after the treatments where fertilization increased the tot-N and NO3 levels and warming reduced the inorganic tot-N, NH4 and NO3. These findings were not confirmed by the results of the extraction. The incubation showed negative net mineralization rates for tot- N and NH4. PRS- probes showed a slightly dominance of NO3 over NH4 while extraction showed a many times higher amount of NH4 compared to NO3. Extraction shows a strong correlation with incubation even though extraction measure an instantaneous value and incubation measure the production of inorganic nitrogen over time.

  • 348.
    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 anläggning2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    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. 

  • 349. Eklöv, Peter
    et al.
    Svanbäck, Richard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Predation favors adaptive morphological variation in perch populationsManuskript (Annet vitenskapelig)
  • 350.
    Ekström, Magnus
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik.
    Esseen, Per-Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Westerlund, B.
    Grafström, A.
    Jonsson, B. G.
    Ståhl, G.
    Logistic regression for clustered data from environmental monitoring programs2018Inngår i: Ecological Informatics, ISSN 1574-9541, E-ISSN 1878-0512, Vol. 43, s. 165-173Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Large-scale surveys, such as national forest inventories and vegetation monitoring programs, usually have complex sampling designs that include geographical stratification and units organized in clusters. When models are developed using data from such programs, a key question is whether or not to utilize design information when analyzing the relationship between a response variable and a set of covariates. Standard statistical regression methods often fail to account for complex sampling designs, which may lead to severely biased estimators of model coefficients. Furthermore, ignoring that data are spatially correlated within clusters may underestimate the standard errors of regression coefficient estimates, with a risk for drawing wrong conclusions. We first review general approaches that account for complex sampling designs, e.g. methods using probability weighting, and stress the need to explore the effects of the sampling design when applying logistic regression models. We then use Monte Carlo simulation to compare the performance of the standard logistic regression model with two approaches to model correlated binary responses, i.e. cluster-specific and population-averaged logistic regression models. As an example, we analyze the occurrence of epiphytic hair lichens in the genus Bryoria; an indicator of forest ecosystem integrity. Based on data from the National Forest Inventory (NFI) for the period 1993-2014 we generated a data set on hair lichen occurrence on > 100,000 Picea abies trees distributed throughout Sweden. The NFI data included ten covariates representing forest structure and climate variables potentially affecting lichen occurrence. Our analyses show the importance of taking complex sampling designs and correlated binary responses into account in logistic regression modeling to avoid the risk of obtaining notably biased parameter estimators and standard errors, and erroneous interpretations about factors affecting e.g. hair lichen occurrence. We recommend comparisons of unweighted and weighted logistic regression analyses as an essential step in development of models based on data from large-scale surveys.

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