| 1. |
- Ericson, Lars, et al.
(författare)
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Bevara de värdefulla skogar som ännu finns kvar i Sverige
- 2017
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN Debatt: Sverige har åtagit sig att skydda 20 procent av landets land- och sötvattensområden till 2020. Men hittills har bara 4–5 procent av den omfattande produktiva skogen bevarats. För att nå de demokratiskt beslutade målen måste Skogsstyrelsens beslut om stopp för inventering av nyckelbiotoper hävas, skriver sju forskare.
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| 2. |
- 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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| 3. |
- Prentice, Honor C., et al.
(författare)
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Fragmented grasslands on the Baltic island of Öland : Plant community composition and land-use history
- 2007
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Ingår i: Acta Phytogeographica Suecica. - 0084-5914. ; 88, s. 83-94
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Forskningsöversikt (refereegranskat)abstract
- The relationships between properties of present landscapes and species diversity within fragmented grasslands have been the subject of many studies. However the potential roles of grassland history and past landscape structure as determinants of diversity have not been widely studied. We therefore focus on these roles with an overview of patterns of variation in plant community composition in grassland fragments, of known ages, within a 22 km2 site around the village of Jordtorp on the Baltic island of Öland. While the frequencies of individual vascular plant species in 328 50 cm × 50 cm quadrats showed trends related to grassland continuity and previous land use, the dominant gradients of plant community composition were interpreted in terms of gradients of soil moisture and eutrophication. Because relationships between grassland age and plant community composition are confounded by local grassland eutrophication, it is difficult to use the present grassland data set to draw conclusions about the extent to which the distributions of individual species reflect a long history of continuous grassland management or an absence of eutrophication. Our results suggest that studies that attempt to explore associations between grassland age and fine-scale species richness, or the occurrence of individual species, should be based on sampling rules that standardize the type of plant community that is to be compared between grassland fragments.
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| 4. |
- Prentice, Honor C., et al.
(författare)
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Gene diversity in a fragmented population of Briza media: grassland continuity in a landscape context
- 2006
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 94:1, s. 87-97
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Tidskriftsartikel (refereegranskat)abstract
- 1. We investigated patterns of allozyme variation in demes of the grass Briza media in semi-natural grassland fragments within a mosaic agricultural landscape on the Baltic island of Öland. In the study area, Briza is both a characteristic species of old pastures and an early colonizer of young grasslands developing on previously forested or arable sites. 2 Generalized linear models revealed that descriptors of both present landscape structure and past grassland history are significant determinants of genetic variation in the Briza demes. Genetic structure and levels of within-deme diversity are influenced by the size of grassland fragments, the type of habitat surrounding the grasslands, the size/spatial extent of the demes, the geographic position of the demes and the historical continuity of the grassland fragments. 3 Gene diversity (H) was higher in demes from grassland polygons with a high proportion of adjacent grassland, higher in the more extensive demes, and decreased northwards within the study area. 4 The negative association between the inbreeding coefficient (FIS) and grassland continuity is interpreted in terms of a two-stage colonization process: recruitment into young grasslands leads initially to spatial patchiness, but subsequent selection in maturing pastures occurs within an increasingly uniform and dense sward. 5 Despite a weak overall genetic structure (as indicated by Bayesian cluster analysis) the between-deme FST was significant. Linear discriminant analysis of within-deme allele frequencies grouped the demes according to the age and previous land-use history of their grassland polygons. The convergence of the allele frequency profiles in the younger grasslands towards those of the old grasslands is consistent with convergence of selective regimes as pastures mature towards an increasingly uniform, dense sward and characteristic species assemblage. 6 The genetic composition of demes of a grassland species appears to be influenced by the process of plant community convergence during grassland development – complementing the recent finding that convergence of species composition in experimental assemblages of grassland plants is dependent on the genotypic composition of the component species
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