| 21. |
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| 22. |
- Hathaway, Louise, et al.
(författare)
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Experimental crosses within European Silene latifolia (Caryophyllaceae): intraspecific differentiation, distance effects, and sex ratio
- 2009
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Ingår i: Canadian Journal of Botany. - 0008-4026. ; 87:3, s. 231-240
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Tidskriftsartikel (refereegranskat)abstract
- The dioecious weed Silene latifolia Poiret is thought to have spread northwards through Europe from separate southern source populations and shows a pronounced east–west pattern of differentiation in seed morphology. We used crossing experiments to investigate whether patterns of interfertility in S. latifolia are consistent with a scenario of ongoing speciation (reflected by outbreeding depression in crosses between the seed races), a scenario involving local inbreeding (reflected by heterosis in interpopulations crosses), or a combination of both scenarios. The experiments involved three western and three eastern populations, which were crossed reciprocally in all possible inter- and intra-population combinations. Inter-race cross-progenies did not have lower fitness than those from intra-racial crosses, and the results are not consistent with a scenario of incipient speciation. A pattern of overall heterosis was found in three variables, indicating the expression of inbreeding depression in progeny from intrapopulation crosses. For two fitness variables, negative relationships between interpopulation distance and heterosis, together with signs of outbreeding depression in the longest-distance crosses, suggest that there may be significant levels of genetic differentiation between geographically distant populations. The sex ratio was female-biased in most progenies, especially in those from the longest-distance crosses.
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| 23. |
- Hathaway, Louise, et al.
(författare)
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Geographically congruent large-scale patterns of plastid haplotype variation in the European herbs Silene dioica and S-latifolia (Caryophyllaceae)
- 2009
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Ingår i: Botanical Journal of the Linnean Society. - 1095-8339. ; 161:2, s. 153-170
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Tidskriftsartikel (refereegranskat)abstract
- The closely related dioecious herbs Silene latifolia and Silene dioica are widespread and predominantly sympatric in Europe. The species are interfertile, but morphologically and ecologically distinct. A study of large-scale patterns of plastid DNA (polymerase chain reaction-restriction fragment length polymorphism) haplotypes in a sample of 198 populations from most of the European ranges of both species revealed extensive interspecific haplotype sharing. Four of the 28 detected haplotypes were frequent (found in > 40 populations) and widespread. Three of these frequent haplotypes occurred in both species and the geographic distribution of each haplotype was broadly congruent in both species. Each of these three, shared and widespread haplotypes is likely to have colonized central and/or northern Europe after the last glaciation from one or more of refugial areas in southern Europe. Interspecific hybridization and plastid introgression within refugial regions and/or during the early stages of postglacial expansion is the most plausible explanation for the broadly similar distribution patterns of the shared, frequent chloroplast haplotypes in the two species. The fourth frequent, widespread haplotype was absent from S. latifolia and almost entirely restricted to Nordic S. dioica. It is most likely that this haplotype spread into the Nordic countries from a central or northern European source or from a refugial area in Russia. (c) 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 153-170.
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| 24. |
- Irminger Street, Therese, et al.
(författare)
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Predicted effects of management on vascular plant species in arable field margins
- 2010
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Ingår i: Aspects of Applied Biology. - 0265-1491. ; 100, s. 233-243
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Tidskriftsartikel (refereegranskat)abstract
- Many of Sweden’s red listed species are found in the agricultural landscape. Small biotopes (e.g. field margins and field islets) are important for the maintenance of biodiversity in agricultural landscapes, and agri-environmental support is paid to farmers who keep them open. However, a proper evaluation of the biodiversity-gains from this type of management is lacking. We examined the predicted response of vascular plant species in field margins in Scania, S. Sweden, to the removal of woody vegetation and found that more species are expected to show a positive than a negative response to this type of management. Comparison of present-day and historical (1940s) aerial photographs shows that field size and the amount of small biotopes have decreased while the cover of woody vegetation on many of the remaining small biotopes has increased. Changes are greater in the arable plains and in the mixed district than in the forest district.
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| 25. |
- Irminger Street, Therese, et al.
(författare)
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Removal of woody vegetation from uncultivated field margins is insufficient to promote non-woody vascular plant diversity
- 2015
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Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 1873-2305 .- 0167-8809. ; 201, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Uncultivated field margins are one of the most frequent non-crop habitat types in contemporary, highintensity agricultural landscapes and may therefore be important for the persistence of many farmland species. Managing field margins in a way that preserves, and preferably enhances, their value for biodiversity is therefore important. In the present study, we evaluate how the flora of uncultivated field margins is affected by the removal of woody vegetation as prescribed by an agri-environment scheme (AES) under the Swedish Rural Development Program 2007–2013. We used generalized linear mixed models and detrended correspondence analysis to compare the flora of open (cleared) and more overgrown field margins, located within agricultural landscapes of different complexity, in Scania, S. Sweden. As expected, there was a negative effect of management on woody species. However, the local (1m2) and transect (100 m) level richness of non-woody species did not differ significantly between management categories, and there were no differences in the within-transect variability of non-woody species (local b diversity) or the species composition (0.25m2 plots) in managed and unmanaged field margins. Our results show that the removal of woody vegetation from uncultivated field margins, as prescribed by the evaluated AES, is unlikely to benefit non-woody plant species. The species composition of the sampled field margins suggests that inclusion of appropriate field layer management alone is unlikely to be sufficient to improve habitat conditions for grassland species unless measures are taken to counteract eutrophication. Landscape type, on the other hand, influenced both the total richness and the richness of each of the species groups that were considered to be of particular conservation value in the present study: field margins in the complex agricultural landscapes were significantly richer than those in the simple ones. Maintaining non-crop habitat at the landscape scale is likely to be a necessary first step in the prevention of a further decline of farmland plants.
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| 26. |
- Jeliazkov, Alienor, et al.
(författare)
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A global database for metacommunity ecology, integrating species, traits, environment and space
- 2020
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear how generalizable these relationships are across ecosystems, taxa and spatial scales. To address this gap, we collated 80 datasets from trait-based studies into a global database for metaCommunity Ecology: Species, Traits, Environment and Space; “CESTES”. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available. By its harmonized structure, and the diversity of ecosystem types, taxonomic groups, and spatial scales it covers, the CESTES database provides an important opportunity for synthetic trait-based research in community ecology. © 2020, The Author(s).
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| 27. |
- Johansson, Lotten, et al.
(författare)
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Semi-natural grassland continuity, long-term land-use change and plant species richness in a local agricultural landscape on Öland, Sweden
- 2008
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Ingår i: Landscape and Urban Planning. - : Elsevier BV. - 0169-2046 .- 1872-6062. ; :84, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- The study characterizes historical land-use change and the development of semi-natural grassland habitats, over 274 years, within a mosaic agricultural landscape (22 km2) on the island of O¨ land (Sweden). We also explore the relationship between previous land-use, habitat continuity and present-day vascular plant species richness in grassland patches.Land-cover maps, based on cadastral maps and aerial photographs, wereproduced for six time-periods between 1723/1733 and 1994/1997. In 1723/1733, the landscape was dominated by grasslands, with arable land surrounding the villages. The grassland area decreased throughout the study period and grassland patches became progressively more fragmented.Present-day grasslands represent 18% of the grassland area in 1723/1733. The land-use structure of the early 18th century is still evident in the modern landscape. The majority of the present-day grasslands are situated on former common grazing land and have had a continuity of at least 274 years: the remaining grasslands are younger and developed during the 20th century on arable or forested land.The proportion of plant speciesthat depend on grazing and are characteristic of semi-natural grasslands significantly reflects the continuity and previous land-use of grassland sites. The study illustrates the way in which information on historical land-use and habitat continuity can help to explain the structuring of plant assemblages in semi-natural grasslands within the modern landscape.
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| 28. |
- Jonsell, Bengt, et al.
(författare)
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Silene uniflora Roth ssp. petaea (Hartm.)
- 1996
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Ingår i: Lectotypifications and new combinations for Flora Nordica vol 1(Lycopodiaceae - Papaveraceae). ; 16, s. 6-6
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Bokkapitel (refereegranskat)
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| 29. |
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| 30. |
- Li, Yuan, et al.
(författare)
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Contrasting patterns of nucleotide polymorphism suggest different selective regimes within different parts of the PgiC1 gene in Festuca ovina L
- 2017
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 1601-5223. ; 154
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phosphoglucose isomerase (PGI, EC 5.3.1.9) is an essential metabolic enzyme in all eukaryotes. An earlier study of the PgiC1 gene, which encodes cytosolic PGI in the grass Festuca ovina L., revealed a marked difference in the levels of nucleotide polymorphism between the 5' and 3' portions of the gene.METHODS: In the present study, we characterized the sequence polymorphism in F. ovina PgiC1 in more detail and examined possible explanations for the non-uniform pattern of nucleotide polymorphism across the gene.RESULTS: Our study confirms that the two portions of the PgiC1 gene show substantially different levels of DNA polymorphism and also suggests that the peptide encoded by the 3' portion of PgiC1 is functionally and structurally more important than that encoded by the 5' portion. Although there was some evidence of purifying selection (dN/dS test) on the 5' portion of the gene, the signature of purifying selection was considerably stronger on the 3' portion of the gene (dN/dS and McDonald-Kreitman tests). Several tests support the action of balancing selection within the 5' portion of the gene. Wall's B and Q tests were significant only for the 5' portion of the gene. There were also marked peaks of nucleotide diversity, Tajima's D and the dN/dS ratio at or around a PgiC1 codon site (within the 5' portion of the gene) that a previous study had suggested was subject to positive diversifying selection.CONCLUSIONS: Our results suggest that the two portions of the gene have been subject to different selective regimes. Purifying selection appears to have been the main force contributing to the relatively low level of polymorphism within the 3' portion of the sequence. In contrast, it is possible that balancing selection has contributed to the maintenance of the polymorphism within the 5' portion of the gene.
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