| 41. |
- Liljefors, Max, et al.
(författare)
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Mapped Bodies : Notes on the Use of Biometrics in Geopolitical Contexts
- 2015
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Ingår i: Socioaesthetics. Ambience – Imaginary. - 1572-459X. - 9789004246270 - 9789004303751 ; 19, s. 53-72
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Bokkapitel (refereegranskat)abstract
- “Mapped Bodies: Notes on the Use of Biometrics in Geopolitical Contexts” examines the role played by automated biometric technologies in migration control and in the so-called war on terror. Biometric methods such as automated fingerprint identification, iris scanning and facial recognition record microscopic bodily characteristics, computes patterns from them, and matches those patterns against already existing records in super-national databases. These technologies, we argue, are a telling example of a recasting of the relations between the body and state power, in which two current trends, the ‘biologization’ of the human being and the focus on security in the so-called war on terror, after 9/11 and subsequent terror attacks, are epitomized and combined. Starting from a visual culture studies perspective, this article discusses the negotiations of visibility and invisibility involved in biometrics, in connection to questions of power, subjectivity and citizenship. We draw on Vilém Flusser’s and Paul Virilio’s respective understanding of visual technologies as being ultimately ”blind”. We also draw on Emmanuel Levinas’ and Giorgio Agamben’s elaborations on the human face as an inherently ethical ”depth dimension” of interpersonal encounters, a depth we find at risk of becoming eclipsed by the biometric flattening of bodily topographies into abstract, encoded patterns. Ultimately, we argue, automated biometrics threatens to dissolve the bond between subjectivity and citizenship.
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| 42. |
- Olsrud, Maria, et al.
(författare)
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Responses of fungal root colonization, plant cover and leaf nutrients to long-term exposure to elevated atmospheric CO2 and warming in a subarctic birch forest understory
- 2010
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 16:6, s. 1820-1829
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Tidskriftsartikel (refereegranskat)abstract
- Responses of the mycorrhizal fungal community in terrestrial ecosystems to global change factors are not well understood. However, virtually all land plants form symbiotic associations with mycorrhizal fungi, with approximately 20% of the plants' net primary production transported down to the fungal symbionts. In this study, we investigated how ericoid mycorrhiza (ErM), fine endophytes (FE) and dark septate endophytes (DSE) in roots responded to elevated atmospheric CO2 concentrations and warming in the dwarf shrub understory of a birch forest in the subarctic region of northern Sweden. To place the belowground results into an ecosystem context we also investigated how plant cover and nutrient concentrations in leaves responded to elevated atmospheric CO2 concentrations and warming. The ErM colonization in ericaceous dwarf shrubs increased under elevated atmospheric CO2 concentrations, but did not respond to warming following 6 years of treatment. This suggests that the higher ErM colonization under elevated CO2 might be due to increased transport of carbon belowground to acquire limiting resources such as N, which was diluted in leaves of ericaceous plants under enhanced CO2. The elevated CO2 did not affect total plant cover but the plant cover was increased under warming, which might be due to increased N availability in soil. FE colonization in grass roots decreased under enhanced CO2 and under warming, which might be due to increased root growth, to which the FE fungi could not keep up, resulting in proportionally lower colonization. However, no responses in aboveground cover of Deschampsia flexuosa were seen. DSE hyphal colonization in grass roots significantly increased under warmer conditions, but did not respond to elevated CO2. This complex set of responses by mycorrhizal and other root-associated fungi to global change factors of all the fungal types studied could have broad implications for plant community structure and biogeochemistry of subarctic ecosystems.
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| 43. |
- Pascual, Didac, et al.
(författare)
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The missing pieces for better future predictions in subarctic ecosystems: A Torneträsk case study
- 2021
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 50:2, s. 375-392
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Forskningsöversikt (refereegranskat)abstract
- Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.
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| 44. |
- Rinnan, Riikka, et al.
(författare)
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Effects of litter addition and warming on soil carbon, nutrient pools and microbial communities in a subarctic heath ecosystem
- 2008
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393. ; 39:3, s. 271-281
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Tidskriftsartikel (refereegranskat)abstract
- Climatic warming leads to the expansion of deciduous shrubs and trees in the Arctic. This leads to higher leaf litter inputs, which together with warming may alter the rate of carbon and nutrient cycling in the arctic ecosystems. We assessed effects of factorial warming and additional litter on the soil ecosystem of a subarctic heath in a 7-year-long field experiment. Fine root biomass, dissolved organic carbon (DOC) and total C concentration increased in response to warming, which probably was a result of the increased vegetation cover. Litter addition increased the concentration of inorganic P in the uppermost 5 cm soil, while decreasing the pool of total P per unit area of the organic profile and having no significant effects on N concentrations or pools. Microbial biomass C and N were unaffected by the treatments, while the microbial biomass P increased significantly with litter addition. Soil ergosterol concentration was also slightly increased by the added litter in the uppermost soil, although not statistically significantly. According to a principal component analysis of the phospholipid fatty acid profiles, litter addition differed from the other treatments by increasing the relative proportion of biomarkers for Gram-positive bacteria. The combined warming plus litter addition treatment decreased the soil water content in the uppermost 5 cm soil, which was a likely reason for many interactions between the effects of warming and litter addition. The soil organic matter quality of the combined treatment was also clearly different from the control based on a near-infrared reflectance (NIR) spectroscopic analysis, implying that the treatment altered the composition of soil organic matter. However, it appears that the biological processes and the microbial community composition responded more to the soil and litter moisture conditions than to the change in the quality of the organic matter.
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| 45. |
- Rinnan, Riikka, et al.
(författare)
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Fungi benefit from two decades of increased nutrient availability in tundra heath soil.
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- If microbial degradation of carbon substrates in arctic soil is stimulated by climatic warming, this would be a significant positive feedback on global change. With data from a climate change experiment in Northern Sweden we show that warming and enhanced soil nutrient availability, which is a predicted long-term consequence of climatic warming and mimicked by fertilization, both increase soil microbial biomass. However, while fertilization increased the relative abundance of fungi, warming caused only a minimal shift in the microbial community composition based on the phospholipid fatty acid (PLFA) and neutral lipid fatty acid (NLFA) profiles. The function of the microbial community was also differently affected, as indicated by stable isotope probing of PLFA and NLFA. We demonstrate that two decades of fertilization have favored fungi relative to bacteria, and increased the turnover of complex organic compounds such as vanillin, while warming has had no such effects. Furthermore, the NLFA-to-PLFA ratio for (13)C-incorporation from acetate increased in warmed plots but not in fertilized ones. Thus, fertilization cannot be used as a proxy for effects on warming in arctic tundra soils. Furthermore, the different functional responses suggest that the biomass increase found in both fertilized and warmed plots was mediated via different mechanisms.
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| 46. |
- Rinnan, Riikka, et al.
(författare)
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Long-term warming of a subarctic heath decreases soil bacterial community growth but has no effects on its temperature adaptation
- 2011
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393. ; 47:3, s. 217-220
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Tidskriftsartikel (refereegranskat)abstract
- We tested whether bacterial communities of subarctic heath soil are adapted to elevated temperature after experimental warming by open-top greenhouses for 7 or 17 years. The long-term warming by 1-2 degrees C significantly decreased bacterial community growth, by 28% and 73% after 7 and 17 years, respectively. The decrease was most likely due to decreased availability of labile substrate under warming. However, we found no evidence for temperature adaptation of soil bacterial communities. The optimum temperature for bacterial growth was on average 25 C, and the apparent minimum temperature for growth between -7.3 and -6.1 degrees C. and both were unaffected by warming. (C) 2011 Elsevier B.V. All rights reserved.
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| 47. |
- Rinnan, Riikka, et al.
(författare)
-
Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter
- 2007
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Ingår i: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 39:12, s. 3014-3023
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Tidskriftsartikel (refereegranskat)abstract
- Arctic soil carbon (C) stocks are threatened by the rapidly advancing global warming. In addition to temperature, increasing amounts of leaf litter fall following from the expansion of deciduous shrubs and trees in northern ecosystems may alter biogeochemical cycling of C and nutrients. Our aim was to assess how factorial warming and litter addition in a long-term field experiment on a subarctic heath affect resource limitation of soil microbial communities (measured by thymidine and leucine incorporation techniques), net growing-season mineralization of nitrogen (N) and phosphorus (P), and carbon turnover (measured as changes in the pools during a growing-season-long field incubation of soil cores in situ). The mainly N limited bacterial communities had shifted slightly towards limitation by C and P in response to seven growing seasons of warming. This and the significantly increased bacterial growth rate under warming may partly explain the observed higher C loss from the warmed soil. This is furthermore consistent with the less dramatic increase in the contents of dissolved organic carbon (DOC) and dissolved organic N (DON) in the warmed soil than in the soil from ambient temperature during the field incubation. The added litter did not affect the carbon content, but it was a source of nutrients to the soil, and it also tended to increase bacterial growth rate and net mineralization of P. The inorganic N pool decreased during the field incubation of soil cores, especially in the separate warming and litter addition treatments, while gross mineralized N was immobilized in the biomass of microbes and plants transplanted into the incubates soil cores, but without any significant effect of the treatments. The effects of warming plus litter addition on bacterial growth rates and of warming on C and N transformations during field incubation suggest that microbial activity is an important control on the carbon balance of arctic soils under climate change.
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| 48. |
- Rousk, Kathrin, et al.
(författare)
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Across-Habitat Comparison of Diazotroph Activity in the Subarctic
- 2015
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Ingår i: Microbial Ecology. - : Springer Science and Business Media LLC. - 0095-3628 .- 1432-184X. ; 69:4, s. 778-787
-
Tidskriftsartikel (refereegranskat)abstract
- Nitrogen (N) fixation by N-2-fixing bacteria (diazotrophs) is the primary N input to pristine ecosystems like boreal forests and subarctic and arctic tundra. However, the contribution by the various diazotrophs to habitat N-2 fixation remains unclear. We present results from in situ assessments of N-2 fixation of five diazotroph associations (with a legume, lichen, feather moss, Sphagnum moss and free-living) incorporating the ground cover of the associations in five typical habitats in the subarctic (wet and dry heath, polygon-heath, birch forest, mire). Further, we assessed the importance of soil and air temperature, as well as moisture conditions for N-2 fixation. Across the growing season, the legume had the highest total as well as the highest fraction of N-2 fixation rates at habitat level in the heaths (> 85 % of habitat N-2 fixation), whereas the free-living diazotrophs had the highest N-2 fixation rates in the polygon heath (56 %), the lichen in the birch forest (87 %) and Sphagnum in the mire (100 %). The feather moss did not contribute more than 15 % to habitat N-2 fixation in any of the habitats despite its high ground cover. Moisture content seemed to be a major driver of N-2 fixation in the lichen, feather moss and free-living diazotrophs. Our results show that the range of N-2 fixers found in pristine habitats contribute differently to habitat N-2 fixation and that ground cover of the associates does not necessarily mirror contribution.
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| 49. |
- Rousk, Kathrin, et al.
(författare)
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Microbial control of soil organic matter mineralization responses to labile carbon in subarctic climate change treatments
- 2016
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 22:12, s. 4150-4161
-
Tidskriftsartikel (refereegranskat)abstract
- Half the global soil carbon (C) is held in high-latitude systems. Climate change will expose these to warming and a shift towards plant communities with more labile C input. Labile C can also increase the rate of loss of native soil organic matter (SOM); a phenomenon termed ‘priming’. We investigated how warming (+1.1 °C over ambient using open top chambers) and litter addition (90 g m−2 yr−1) treatments in the subarctic influenced the susceptibility of SOM mineralization to priming, and its microbial underpinnings. Labile C appeared to inhibit the mineralization of C from SOM by up to 60% within hours. In contrast, the mineralization of N from SOM was stimulated by up to 300%. These responses occurred rapidly and were unrelated to microbial successional dynamics, suggesting catabolic responses. Considered separately, the labile C inhibited C mineralization is compatible with previously reported findings termed ‘preferential substrate utilization’ or ‘negative apparent priming’, while the stimulated N mineralization responses echo recent reports of ‘real priming’ of SOM mineralization. However, C and N mineralization responses derived from the same SOM source must be interpreted together: This suggested that the microbial SOM-use decreased in magnitude and shifted to components richer in N. This finding highlights that only considering SOM in terms of C may be simplistic, and will not capture all changes in SOM decomposition. The selective mining for N increased in climate change treatments with higher fungal dominance. In conclusion, labile C appeared to trigger catabolic responses of the resident microbial community that shifted the SOM mining to N-rich components; an effect that increased with higher fungal dominance. Extrapolating from these findings, the predicted shrub expansion in the subarctic could result in an altered microbial use of SOM, selectively mining it for N-rich components, and leading to a reduced total SOM-use.
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| 50. |
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