| 1. |
- Krebs, C. J., et al.
(author)
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Terrestrial trophic dynamics in the Canadian Arctic
- 2003
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In: Canadian Journal of Zoology-Revue Canadienne De Zoologie. ; 81, s. 827-843
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Journal article (peer-reviewed)abstract
- The Swedish Tundra Northwest Expedition of 1999 visited 17 sites throughout the Canadian Arctic. At 12 sites that were intensively sampled we estimated the standing crop of plants and the densities of herbivores and predators with an array of trapping, visual surveys, and faecal-pellet transects. We developed a trophic-balance model using ECOPATH to integrate these observations and determine the fate of primary and secondary production in these tundra ecosystems, which spanned an 8-fold range of standing crop of plants. We estimated that about 13% of net primary production was consumed by herbivores, while over 70% of small-herbivore production was estimated to flow to predators. Only 9% of large-herbivore production was consumed by predators. Organization of Canadian Arctic ecosystems appears to be more top-down than bottom-up. Net primary production does not seem to be herbivore-limited at any site. This is the first attempt to integrate trophic dynamics over the entire Canadian Arctic.
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| 2. |
- Karlsson, Sofia A., et al.
(author)
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The impact of a changed legislation on reporting of adverse drug reactions in Sweden, with focus on nurses' reporting
- 2015
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In: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 0031-6970 .- 1432-1041. ; 71:5, s. 631-636
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Journal article (peer-reviewed)abstract
- Purpose: In March 2007, a legislative amendment was issued in Sweden compelling nurses to report all suspected adverse drug reactions (ADRs) to the national pharmacovigilance system. The aims of this study were to describe the status of ADR reporting, before and after the implementation of the legislative changes, and to describe the general characteristics of suspected ADRs reported by nurses. Methods: The Swedish pharmacovigilance system during the study period constituted six regional centres responsible for the handling of all spontaneous ADR reports within their region. In this study, we identified all individual ADR reports from 2005 and 2010, analysed in depth the ADR reports from two regional centres and collated information about the reporter and the nature of the reported ADR. Results: From the two regional centres, a total of 898 and 1074 reports were submitted in 2005 and 2010 respectively. Nurses submitted 31% (275 reports) of the reports in 2005 and 24% (260 reports) in 2010. Nurses' reporting of serious ADRs was 3% (seven reports) in 2005 and 7% (17 reports) in 2010 with reporting of unlabelled ADRs at 4% (11 reports) in 2005 and 17% (45 reports) in 2010. Most of the serious and/or unlabelled reactions were related to vaccine administration (14 reports in 2005 and 36 reports in 2010). Conclusions: The overall ADR reporting by nurses did not appear to increase after the change in reporting legislation. The proportion of serious and/or unlabelled ADRs reported by nurses did however appear to increase during the same period. Taken together, our data suggests that further pro-active measures should be considered in order to involve nurses in the reporting of suspected ADRs.
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| 3. |
- Ampomah, Osei Y., et al.
(author)
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Nodulation and ecological significance of indigenous legumes in Scotland and Sweden
- 2012
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In: Symbiosis. - : Springer Nature. - 0334-5114 .- 1878-7665. ; 57:3, s. 133-148
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Journal article (peer-reviewed)abstract
- The ability of wild indigenous legumes to form root nodules capable of biological nitrogen (N 2) fixation has rarely been demonstrated for species in natural ecosystems in large parts of Europe. In order to understand and manage these ecosystems, it is important to demonstrate nodulation across a diverse range of environments, sites and climates. This study surveyed nodulation at a number of sites in Scotland and Sweden. Presence of nodules was noted and nodule structure and indicators of nitrogen fixation capacity were assessed using light and transmission electron microscopy. Soils from several sites were also sampled for carbon and nitrogen analysis. The collections comprised 24 species in Scotland, and 30 taxa in Sweden; 17 of these in common for both countries. Highest species numbers occurred in meadows, farmland margins, hedgerows, roadsides and wasteland. Coastal sites and sites in the mountainous region above the Arctic Circle hosted several rare species. All sampled species had features of N 2-fixing nodules such as pink colour (leghaemoglobin) when dissected and bacteroids. Nodule structure for a number of species is here reported for the first time and presence of the N 2-fixing enzyme nitrogenase is demonstrated in three previously not studied Swedish legume species. North European legumes may make significant contributions to the N-budgets of their ecosystems. Such species (and their symbionts) represent unique germplasm that may be adopted to empower advances in agriculture and conservation aimed at mitigation and adaptation to the effects of climate change.
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| 12. |
- Krebs, C. J., et al.
(author)
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Synchrony in lemming and vole populations in the Canadian Arctic
- 2002
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In: Canadian Journal of Zoology-Revue Canadienne De Zoologie. ; 80:8, s. 1323-1333
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Journal article (peer-reviewed)abstract
- Population fluctuations may occur in synchrony among several rodent species at a given site, and they may occur in synchrony over large geographical areas. We summarize information on synchrony in lemmings and voles from the Canadian Arctic for the past 20 years. The most detailed available information is from the central Canadian Arctic, where snap-trap samples have been taken annually at several sites for periods of up to 15 years. Geographical synchrony in the same species among different sites was strong, especially for the central and eastern Canadian Arctic. Synchrony among different species at a given site was also generally high. When one species is at high density, densities of all species at that site tend to be high. These results do not easily fit the mobile-predator hypothesis proposed to explain regional synchrony, and are more consistent with the weather hypothesis, which we suggest both entrains synchrony among sites and enforces synchrony among species within a site. We tentatively support the weather hypothesis for geographical synchrony in lemmings, and recommend the establishment of a circumpolar program to monitor lemming cycles and predator movements that would advance our understanding of these large-scale patterns of cyclic synchrony.
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| 14. |
- Puentes, Adriana, et al.
(author)
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Endophytic fungi in Festuca pratensis grown in Swedish agricultural grasslands with different managements
- 2007
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In: Symbiosis. - 0334-5114 .- 1878-7665. ; 44:1/3, s. 121-126
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Journal article (peer-reviewed)abstract
- Cool-season forage grasses infected with asexual endophytic fungi (Neotyphodium spp.) often have advantages over uninfected grasses, including increased herbivore resistance. Since these fungi reproduce by growing into the developing seeds of the host, hyphal loading (amount of fungal hyphae in the plant) gives important information about the balance between host and endophyte in the symbiosis. This work provides insights into how ecological factors external to the symbiosis may influence the symbiosis. By repeated sampling of the same infected plants, we investigated how hyphal loading changes in Festuca pratensis through the growing season and how it is affected by fertilization and ley age in northern Sweden. Infection frequency in F. pratensis ranged from 25-65%. Hyphal loading, based on standard curves of immunoblot assay imprint intensity versus counts of hyphal density across grass leaf sheaths, increased significantly during the growing season and was correlated with cumulative degree days. There were no clear effects of fertilization treatment or ley age on hyphal loading. The symbiosis deserves furher study with respect to plant physiology, ecology, crop production and forage quality.
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| 15. |
- Skarpe, C., et al.
(author)
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Plant-Herbivore Interactions
- 2014
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In: Elephants and Savanna Woodland Ecosystems. - Chichester, UK : Wiley-Blackwell. - 9781118858615 - 9780470671764 ; , s. 189-206
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Book chapter (peer-reviewed)abstract
- To a casual observer, the importance of large herbivores for ecosystem structure and dynamics can seem more obvious in African savannas than in many other ecosystems because of their high abundance, diversity and species richness of ungulates. African savannas have also had a long uninterrupted history of mammalian herbivory, leading to the evolution of plant traits adapted to herbivory and to reciprocal traits in herbivores. In nutrient-poor savannas such as those on Kalahari sand in the Chobe National Park, Botswana, elephants, Loxodonta africana, are a main agent creating spatial and temporal variation in the vegetation and ecosystems. Within this framework, elephants and smaller herbivores interact with individual plants and plant populations, exploiting and modifying heterogeneity at many scales. Intermittent grazing in systems of migratory or highly mobile herbivores provides food plants with a recovery period, and could be one reason for the 'success' and abundance of many migratory herbivore species.
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| 16. |
- Wallgren, Märtha, et al.
(author)
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Influence of land use on the abundance of wildlife and livestock in the Kalahari, Botswana
- 2009
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In: Journal of Arid Environments. - : Elsevier BV. - 0140-1963 .- 1095-922X. ; 73:3, s. 314-321
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Journal article (peer-reviewed)abstract
- Human land use such as pastoralism may be a key determinant of wildlife populations. We studied the influence of land use on wildlife and livestock in south-western Kalahari, Botswana, during the wet and dry seasons. We included two types of livestock areas and two types of wildlife protection areas. Wild and domestic mammals >0.2 kg were sampled by distance technique. Small mammals <0.2 kg were trapped and a vegetation survey was performed. Livestock and some medium-sized wildlife species were most abundant in livestock areas, while large-sized wildlife species were mainly restricted to wildlife areas. Most red-listed species were confined to the national park. The influence of land use on abundances changed moderately between seasons. However, cattle moved into wildlife areas during the wet season. Differences in species richness and diversity were most pronounced during the dry season. The trapping frequency of small mammals was highest in the national park. Differences in vegetation structure included sparser field layer and higher cover of an invasive shrub in livestock areas. Our study shows the importance of protected areas for many wildlife species in the Kalahari. It also shows the value of a multi-species approach for investigating the effects of land use on wildlife communities.
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