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- Löfgren, Stefan, et al.
(author)
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Impact of whole-tree harvest on soil and stream water acidity in southern Sweden based on HD-MINTEQ simulations and pH-sensitivity
- 2017
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 383, s. 49-60
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Journal article (peer-reviewed)abstract
- The shift in major drivers of acidification from sulfur deposition to biological acidification has put the focus on the impact of biomass harvest for bioenergy on the acid base status of forests soils and surface waters. This paper presents a model-based assessment in which the impact of whole-tree harvest (WTH) is compared with that of no harvest at two different sulfur deposition levels by use of the HD-MINTEQ model. Additionally, the pH-sensitivity of 179 randomly selected boreal headwater streams was assessed. The results indicate that the exchangeable Ca2+ pool in humus and mineral soils (<= B-horizon) is most affected by harvest. Concerning the pH, the WTH impact is restricted to shallow soils and for a much shorter period of time. The impact of WTH on the soil solution was primarily restricted to the recharge area and much less pronounced in the discharge area. Due to high buffering capacity of riparian soils and low pH-sensitivity of many headwater streams, the pH effects of WTH on surface waters will most probably be small, at least over a rotation period of several decades. Over time perspectives of multiple rotations, the pH effects are more uncertain due to a possible slow successive protonation of organic matter in the riparian zone. Another important aspect is the currently restricted availability of mobile anion charge balancing the acidity produced by tree growth. Therefore, the acidity is to a large extent arrested in the soil. At the current low S deposition levels, southwestern Sweden seems to be the least vulnerable region to further acid input due to high buffer capacity at low pH. The streams in central and northern Sweden are much more pH-sensitive, but restricted availability of mobile strong acid anions and large buffer capacity in the soils make them less vulnerable to WTH. The partly diverging results between experimental and model studies indicate that one or more processes (hydrological, chemical or biological) are not fully understood or that available data are lacking for a proper parameterization. Thus, the results from long-term WTH experiments are very important for understanding the processes involved as well as for improving and validating model predictions. We therefore encourage societal support of maintaining monitoring and research coupled to such experiments. For the future and for improving our current understanding of biogeochemical dynamics in forest ecosystems subjected to active forestry as well as for policy and management purposes, a mixture of experiments and models ought to be used. (C) 2016 Elsevier B.V. All rights reserved.
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| 2. |
- Callaghan, Terry, et al.
(author)
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Multi-Decadal Changes in Tundra Environments and Ecosystems : Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)
- 2011
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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:6, s. 705-716
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Journal article (peer-reviewed)abstract
- Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.
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| 3. |
- Olsson, Cecilia, 1963-, et al.
(author)
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Food that makes you different : the stigma experienced by adolescents with celiac disease
- 2009
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In: Qualitative Health Research. - : Sage Publications. - 1049-7323 .- 1552-7557. ; 19:7, s. 976-984
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Journal article (peer-reviewed)abstract
- For adolescents with celiac disease (CD), a gluten-free diet(GFD) is crucial for health, but compliance is problematic andnoncompliance is common even among those aware of the risks.To better understand their lives with the disease, Swedish CDadolescents were invited to take part in focus group discussions.Data were analyzed for recurrent stigma-related themes acrossthe groups. Adolescents described an awareness of being differentfrom others that was produced by meal appearance and the pooravailability of gluten-free food. The GFD often required discussionsand special requests, so eating in public had the effect ofmaking an invisible condition visible, and thereby creatinga context for felt or enacted stigma. Maintaining invisibilityavoided negative consequences of stigma, and other strategieswere used to reduce the costs of visibility. The results ofthe study show that the GFD can produce stigma experiences inadolescence, and that dietary compliance (or lack thereof) canbe understood in terms of dealing with GFD concealment and disclosure.
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| 4. |
- Rydén, Petra, 1972-, et al.
(author)
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What happens with the healthiness of the diet among Swedish adolescent boys and girls when a gluten-free diet is required?
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Other publication (other academic/artistic)abstract
- Objectives To explore how diagnosis of celiac disease (CD) in early adolescence affects overall food intake and healthiness of the diet in comparison with age- and sex matched controls and children with CD diagnosed in early childhood. Methods This is a longitudinal dietary sub-study of a school-based CD-screening of 12-year-olds (ETICS - Exploring the Iceberg of Coeliacs in Sweden), a part of the PreventCD project. The dietary study was conducted in 2005-2008 and included the following groups resulting from the screening: I) screening-detected CD cases (n=80), II) previously diagnosed CD cases (n=28), and III) two samples of age- and sex matched non-CD children (admission, n=619; follow-up, n=447). All CD cases completed two food-frequency-and-amount-questionnaires (FFQ), covering the previous four weeks; one at admission and one at a follow-up 18-24 months later. The screening-detected CD cases completed the first FFQ before a gluten free diet was initiated. The non-CD children consisted of a cross-sectional sample at each time point, and thus only completed one FFQ each (i.e. either at admission or follow-up). The Goldberg cut-off method was used to validate reported energy intake. The food choices at admission and follow-up were compared among the three groups, and the healthiness of the diet evaluated using two Swedish dietary indexes. Results and Conclusion Intakes of most food groups were similar at baseline. The adolescents diagnosed with CD did only minor changes in their overall food choices. Visible changes were reductions within food groups where gluten-free alternatives are not readily available, such as pastries and pizza. In contrast, total intake of bread and pasta did not change. All three groups scored fairly low on the dietary indexes at both time points, and there is an obvious need to improve the healthiness of the adolescent diet, whether CD is present or not.
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