| 21. |
- Eriksson, Sofia, et al.
(författare)
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Interactions between historical forest composition and ownership affect present composition of older forest in boreal Sweden
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study we reconstruct forest composition during the 1860s for a 71000 ha area in southern boreal Sweden. The aim is to show how historical ownership and associated anthropogenic disturbances act as a source of heterogeneity in the present-day distribution and composition of coniferous and deciduous forest within the commercial production forest. We use older (>110 years) and mature (70-110 years) forest as response variables in generalized linear models with a binominal error distribution. The explanatory variables include size of zone, historical type of ownership zone (village, company, and farm), amount of forest, and forest type. We focus in particular on investigating effects from interacting explanatory variables. The significant statistical associations in the study indicate that patterns of deciduous and coniferous older patches differ, and that deciduous patches differ in relation to age interval. The oldest deciduous patches, for example, are today more likely on areas that had deciduous cover also in the past and stood on forestland managed by farmers, but less likely on the same habitat managed by companies. We show that there are strong effects on present forest composition from historical ownership and forest composition. We argue that by including local data on past ownership combined with knowledge on use patterns management could be better adapted to local landscape dynamics compared to the application of overly generalized patterns or models of boreal dynamics that excludes interactions with management.
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| 22. |
- Eriksson, Sofia, et al.
(författare)
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Interactions between historical forest composition and ownership affect present composition of older forest in boreal Sweden
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study we reconstruct forest composition during the 1860s for a 71000 ha area in southern boreal Sweden. The aim is to show how historical ownership and associated anthropogenic disturbances act as a source of heterogeneity in the present-day distribution and composition of coniferous and deciduous forest within the commercial production forest. We use older (>110 years) and mature (70-110 years) forest as response variables in generalized linear models with a binominal error distribution. The explanatory variables include size of zone, historical type of ownership zone (village, company, and farm), amount of forest, and forest type. We focus in particular on investigating effects from interacting explanatory variables. The significant statistical associations in the study indicate that patterns of deciduous and coniferous older patches differ, and that deciduous patches differ in relation to age interval. The oldest deciduous patches, for example, are today more likely on areas that had deciduous cover also in the past and stood on forestland managed by farmers, but less likely on the same habitat managed by companies. We show that there are strong effects on present forest composition from historical ownership and forest composition. We argue that by including local data on past ownership combined with knowledge on use patterns management could be better adapted to local landscape dynamics compared to the application of overly generalized patterns or models of boreal dynamics that excludes interactions with management.
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| 23. |
- Grandin, Ulf, et al.
(författare)
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Allozyme variation at a PGI locus in differently aged populations of Moehringia trinervia (Caryophyllaceae) in a successional area
- 2002
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 22:3, s. 303-311
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Tidskriftsartikel (refereegranskat)abstract
- We studied genetic effects of the colonisation process during primary succession by analysing allozyme variation at a PGI locus in differently aged populations of Moehringia trinervia, which is a selfing annual with low dispersal ability. The populations studied come from islands and shores created in the 1880s by a drop in the water table of a Swedish lake and from old parts of a large island and of the mainland. The population age is known from five vegetation analyses over a century. We have also analysed the genetic composition of M. trinervia derived from seeds in the soil. Mainland populations had a higher genetic diversity than island populations that were little differentiated and differed genetically from the mainland populations. There was no temporal trend in the distribution of genetic variation on the new islands. The presence of alleles in the extant populations was associated with the proportion of that allele in the seed bank, indicating a main recruitment from the seed bank and not by repeated immigrations. We suggest that some of the new islands were colonised by a few early founders from the mainland. Later colonisation has occurred between adjacent islands, which preserves the founder effect and could explain the uniform, low genetic variation in the island populations
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| 24. |
- Gunnarsson, Urban, et al.
(författare)
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Local-scale genetic structure in the peatmoss Sphagnum fuscum
- 2007
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 16:2, s. 305-312
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Tidskriftsartikel (refereegranskat)abstract
- Sphagnum (peatmoss) dominates huge areas of the Northern Hemisphere and acts as a significant carbon sink on a global scale, yet little is known about the genetic structure of Sphagnum populations. We investigated genetic structure within a population of the common peatmoss Sphagnum fuscum, to assess local patterns of genetic diversity and the spatial extent of clones. One hundred seventeen shoots were sampled from five transects in Fuglmyra, central Norway, and sequenced for three anonymous DNA regions. Five neighbourhood patches were marked along each transect, and from each patch, five stems were sampled for molecular analyses. Seventeen haplotypes could be distinguished and two major groups of haplotypes differed by 12 mutational steps. The two major haplotype groups differed significantly in microhabitat association along the distance to groundwater table and the pH gradients, indicating microhabitat differentiation. The haplotypes within these groups were all genetically similar, differing by one or two mutations. The most common haplotype occurred in four transects separated by 250-m distance. Most of the molecular variation in the population was found among transects, and within patches. Large dominating clones within each transect resulted in low variation explained by the among-patch-within-transect component of spatial structure. Mutation appears to account for a larger proportion of the population variation than recombination. Within the population, vegetative growth and asexual reproduction from gametophyte fragments dominate as the main reproductive mode.
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| 25. |
- Gustafsson, Susanne, et al.
(författare)
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Genetic differentiation and habitat preference of flowering-time variants within Gymnadenia conopsea
- 2003
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Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 91, s. 284-292
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Tidskriftsartikel (refereegranskat)abstract
- Using fast-evolving microsatellites, more slowly evolving ITS markers and performing habitat analyses, we demonstrated a drastic genetic divergence and significant habitat differentiation between early- and late-flowering variants of plants morphologically belonging to Gymnadenia conopsea ssp conopsea. The two phenological variants can either be found in separate or in mixed populations. Information from microsatellite markers and ITS sequences indicated the occurrence of an early historical split between the two flowering-time variants, a split that has been maintained until the present time even within sympatric populations. Early-flowering variants were also far more genetically diverse, had more alleles per microsatellite locus and a wider habitat amplitude than late-flowering variants. As a comparison, we included G. odoratissima in the sequencing study. We found G. odoratissima to be most closely related to the early-flowering type. This indicates a more ancient divergence event between the two flowering-time variants within G. conopsea ssp conopsea than between the two different species G. odoratissima and the early-flowering variant of G. conopsea. Possible explanations to the results arrived at and possible mechanisms maintaining the genetic separation are discussed.
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| 26. |
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| 27. |
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| 28. |
- J:son Lönn, Eva, 1960-
(författare)
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Jobb(iga) nyheter : om dagstidningars bevakning av arbetsmiljöfrågor
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the beginning of this millennium the increasing level of work related illness was de-scribed, in the public debate, as one of the most serious and costly social problems of our times. An important question in the present study is whether or not the newspapers contributed to make their readers, the politicians and other social actors aware of this vast and growing problem.Thus, the main purpose was to find out the extent of the news media coverage on occupational health/ill-health in Swedish newspapers in the end of the 1990s, and the ways in which the topic was framed. Furthermore the intent was to produce a better and deeper understanding of the factors influencing the coverage.Theoretically the study draws on framing theory. Framing here refers to the process through which complex issues are reduced to journalistically manageable dimensions in the construction of news stories, resulting in a text, a news story that presents and high-lights some aspects and perspectives of the perceived reality but not others.A combination of research methods was used - A content and frame analysis of six months of occupational health coverage in seven newspapers; an interview study with journalists and their scientific sources about the news production; a one week’s news-room study aimed at observing the everyday production of news; and finally, a short email survey directed to the editorial staff at the examined news papers, with the purpose to get some indication on how the coverage of occupational health was organised and prioritized at the different newspapers.In the empirical analysis the newspapers´ picturing of occupational health/ill-health was compared with picture emerging from official statistics on occupational sickness and injury. In many respects a deviation was found between the two. Furthermore, simi-larities and differences in content between different newspapers, between different news sections and between news stories written by journalists of different sex, were examined.A key finding is that the Swedish newspapers did not draw their readers’ attention to the extensive and growing problem at the places of work. A majority of the stories related to occupational health/ill-health were episodic, and treated the issues as isolated and random events rather than predictable and preventable problems, although there were also more thematic articles written during special circumstances. The results indicate that a primary cause of the topics low priority in the newspapers was that the coverage of occupational health/ill-health had not been integrated into the journalistic routines.
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| 29. |
- Jonsson, Magnus, et al.
(författare)
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Genetic divergence of climatically marginal populations of Vicia pisiformis on the Scandinavian Peninsula
- 2008
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 145:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Vicia pisiformis L. is a perennial leguminous plant with a main distribution in broadleaved forest-steppes of eastern Europe. The species is classified as endangered (EN) according to the IUCN red-lists in both Norway and Sweden, due to severe fragmentation, small population sizes and continuing population decline. The populations on the Scandinavian Peninsula constitute the northern limit of the species distribution and are mostly restricted to warm stony slopes with predominantly southern aspects. In this study we used the AFLP method, which is a high-resolution genetic fingerprint method. Samples were collected from 22 Scandinavian populations. The overall genetic structure was analysed in an AMOVA, in a Mantel test and through constrained correspondence analysis (CCA). The ordination scores representing non-geographic genetic divergence were extracted from the CCA and analysed in a linear model using habitat variables and population size as explanatory variables. We found (i) a strong geographic structure, (ii) significant genetic divergence between populations, (iii) that this genetic divergence remained significant even after removing the effect of geography in a partial CCA and (iv) that the remaining non-geographic part of genetic divergence (distance from the ordination centre) was associated with aspect, populations with a northern aspect were more genetically divergent. Aspect explains more variation than population size and is the only variable retained in the minimal adequate model. We suggest that local adaptation has caused this divergence from an expected geographical pattern of genetic variation. This explanation is further supported by the association between aspect and specific AFLP fragments. Many plant populations are relics of a different climate (Aguirre-Planter et al. 2000; Despres et al. 2002; Pico and Riba 2002). In response to long-term climate change, populations can either migrate towards a more favourable climate or adapt to the new conditions (delaVega 1996; Jump et al. 2006). Species with limited dispersal ability are at risk of reaching isolated dead-ends of decreasingly suitable habitat, without any suitable habitat within dispersal distance (Colas et al. 1997). Isolated populations have to use their inherent evolutionary potential and adapt to changes in environmental conditions, or they will go extinct. As population fragments go extinct, those that remain will become increasingly isolated from each other both spatially and also genetically as the level of gene flow declines with increasing distance. Such correlation between genetic dissimilarities and geographic distances, known as isolation by distance (Slatkin 1993; Wright 1943), when found, suggests a history of geographically limited gene flow (Kimura and Weiss 1964). On top of an isolation by distance pattern there might be other genetic structures to be found. Occasional long-distance dispersal events for example may disturb geographic patterns with puzzling allele distributions as a result (Nichols and Hewitt 1994). Genetic drift is a process that will affect any pattern of genetic variation in a random fashion. Local adaptation through natural selection is a process that, if sufficiently strong in comparison with gene flow and genetic drift, will create patterns where genetic differentiation is associated with certain environmental conditions (Wright 1951). Several studies have shown the importance of local adaptation of populations (reviewed by Kawecki and Ebert 2004) (see also Bonin et al. 2006; Knight and Miller 2004; Kolseth and Lönn 2005; Lönn et al. 1998). Local adaptation can be strong also at small spatial scales (Snaydon and Davies 1976; Lönn 1993) even though it is sometimes very limited in terms of the number of genes involved (Kärkkainen et al. 2004) Environmental variability provides a base for biological variation by imposing differentiated selection pressures resulting in local adaptation. Topography provides large environmental variation within a relatively small area and thereby provides a basis for small-scale local adaptations. Depending on the local topographic possibilities populations can either migrate up and down slopes or along the same altitude to a different aspect to find a suitable microclimate. The dispersal distance will be much shorter per degree of temperature change during altitudinal migration (Hewitt 1996), than during simple latitudinal migration across a flat landscape. Slope and aspect are two important topographic parameters that determine the influx level of solar radiation, especially towards the poles where the total global radiation decreases (Larcher 2003). Vicia pisiformis is an endangered poorly-dispersed long-lived forest herb with its main distribution across the semi-open broadleaved forest steppes of eastern Europe. The Scandinavian populations are believed to be climate relict populations from warmer times. Earlier genetic studies of V. pisiformis using allozymes, RAPD:s and morhology, have found low to very low levels of genetic variation (Gustafsson and Gustafsson 1994; Black-Samuelsson et al. 1997; Black-Samuelsson and Lascoux 1999). Therefore we used AFLP (amplified fragment length polymorphism) markers, which detect even very small genetic differences between individuals. AFLP mainly analyse neutral variation, as the major fraction of most genomes is assumed to be neutral. However, since the AFLP-fragments are distributed randomly throughout the whole genome some fragments may be situated so close to regions under selection that they become more or less linked to them. This linkage disequilibrium between molecular markers and regions under selection, often referred to as quantitative trait loci (QTL), forms the basis for both QTL-mapping and marker assisted selection (MAS), reviewed by Dekkers and Hospital (2002). Gardner and Latta (2006) for example, found QTL under selection in both natural environments and in the greenhouse. Markers have been found to be connected to biomass production (Cavagnaro et al. 2006) and environmental variation (Bonin et al. 2006; Jump et al. 2006; Porcher et al. 2006). In this study we examine 22 Swedish and Norwegian populations of Vicia pisiformis and ask (i) if there is genetic differentiation between these populations, (ii) if there is can it be explained in its entirety by geographic location or (iii) can it partly be explained by habitat characteristics, suggesting local adaptation, or population size, suggesting genetic drift. We show that populations are differentiated geographically and that genetic variation in addition to the geographical pattern is associated with habitat.
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| 30. |
- Juell-Skielse, Gustaf, et al.
(författare)
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Modes of collaboration and expected benefits of inter-organizational E-government initiatives : A multi-case study
- 2017
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Ingår i: Government Information Quarterly. - : Elsevier. - 0740-624X .- 1872-9517. ; 34:4, s. 578-590
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Tidskriftsartikel (refereegranskat)abstract
- Collaboration among governmental organizations has been regarded as essential for realizing benefits of e-government investments. Inter-organizational collaboration on e-government can appear in several forms and can aim at varying types of benefits. However, few if any studies have delved deeper into analysis of how chosen forms of collaboration might relate to targeted e-government benefits. This article studies five cases of how contemporary acquisitions and implementations of digital archiving systems have been launched through five modes of collaboration (autonomous, standardization, framework agreement, consortium, and central service organization) among organizations in the Swedish public sector. Our analysis reveals that whereas the target system, digital archive in our case, stays similar, expected benefits vary. The article contributes by elaborating the concept of mode of collaboration that identifies typical benefits justifying a choice of a particular collaboration form on e-government development and describing the five modes in more detail based on a multi-case study. The article also outlines fourteen related propositions of the correlation between the collaboration modes and expected benefits to be verified by further research.
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