| 1. |
- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
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Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 2. |
- Lejaeghere, Kurt, et al.
(författare)
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Reproducibility in density functional theory calculations of solids.
- 2016
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 351:6280, s. 1415-1422
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Tidskriftsartikel (refereegranskat)abstract
- The widespread popularity of density functional theory has given rise to an extensive range of dedicated codes for predicting molecular and crystalline properties. However, each code implements the formalism in a different way, raising questions about the reproducibility of such predictions. We report the results of a community-wide effort that compared 15 solid-state codes, using 40 different potentials or basis set types, to assess the quality of the Perdew-Burke-Ernzerhof equations of state for 71 elemental crystals. We conclude that predictions from recent codes and pseudopotentials agree very well, with pairwise differences that are comparable to those between different high-precision experiments. Older methods, however, have less precise agreement. Our benchmark provides a framework for users and developers to document the precision of new applications and methodological improvements.
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| 3. |
- Serge, M. A., et al.
(författare)
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Testing the Effect of Relative Pollen Productivity on the REVEALS Model : A Validated Reconstruction of Europe-Wide Holocene Vegetation
- 2023
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Ingår i: Land. - : MDPI. - 2073-445X. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1 degrees x 1 degrees) over the Holocene (last 11.7 ka BP) using the 'Regional Estimates of VEgetation Abundance from Large Sites' (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity.
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| 4. |
- Björkman, Anne, 1981, et al.
(författare)
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Tundra Trait Team: A database of plant traits spanning the tundra biome
- 2018
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 27:12, s. 1402-1411
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 The Authors Global Ecology and Biogeography Published by John Wiley & Sons Ltd Motivation: The Tundra Trait Team (TTT) database includes field-based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade-offs, trait–environment relationships and environmental filtering, and trait variation across spatial scales, to validate satellite data, and to inform Earth system model parameters. Main types of variable contained: The database contains 91,970 measurements of 18 plant traits. The most frequently measured traits (>1,000 observations each) include plant height, leaf area, specific leaf area, leaf fresh and dry mass, leaf dry matter content, leaf nitrogen, carbon and phosphorus content, leaf C:N and N:P, seed mass, and stem specific density. Spatial location and grain: Measurements were collected in tundra habitats in both the Northern and Southern Hemispheres, including Arctic sites in Alaska, Canada, Greenland, Fennoscandia and Siberia, alpine sites in the European Alps, Colorado Rockies, Caucasus, Ural Mountains, Pyrenees, Australian Alps, and Central Otago Mountains (New Zealand), and sub-Antarctic Marion Island. More than 99% of observations are georeferenced. Time period and grain: All data were collected between 1964 and 2018. A small number of sites have repeated trait measurements at two or more time periods. Major taxa and level of measurement: Trait measurements were made on 978 terrestrial vascular plant species growing in tundra habitats. Most observations are on individuals (86%), while the remainder represent plot or site means or maximums per species. Software format: csv file and GitHub repository with data cleaning scripts in R; contribution to TRY plant trait database (www.try-db.org) to be included in the next version release.
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| 5. |
- Björkman, Beyza, 1973-
(författare)
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Spoken Lingua Franca English at a Swedish Technical University : An investigation of form and communicative effectiveness
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As a part of the process of globalization, an increasing number of higher education institutions are adopting English as the medium of instruction for parts of their education. Within most universities in continental Europe, there are English as a lingua franca (ELF) settings where English is spoken by users of a wide spectrum of first languages for various purposes, be it for academic activity or social interaction. This is clearly the case for Sweden, where higher education has become increasingly international and thus linguistically diverse, for educational, idealistic and financial reasons. This study reports the findings of a project that investigated the form and pragmatics of spoken lingua franca English in Swedish higher education. The group in focus is exclusively engineering students and lecturers in content courses. The results are based on authentic data from high-stakes spoken communication. The study comprises two dimensions, namely form and communicativeness. In the form dimension, the material was checked extensively for non-standard morphosyntactic features. In the second dimension, communicativeness was investigated. The emphasis was then put on the discourse level for further examination, and the material was checked intensively for pragmatic strategies. Finally, a survey was carried out to investigate perceived communicativeness and attitudes towards morphosyntactic non-standardness. The results indicate that communication takes place without much overt disturbance in this lingua franca setting with the exception of non-standard question formulation. Pragmatically, these speakers use a variety of strategies to negotiate and clarify meaning, such as commenting on discourse structure, signaling importance etc. Finally, the results of the survey show some irritation towards non-standardness. From these results, the notion of effectiveness in ELF settings emerges as being determined primarily by pragmatic ability and less by proficiency.
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| 6. |
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| 7. |
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| 8. |
- Björkman, John, et al.
(författare)
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Kärlekens kulturhistoria : En introduktion
- 2020
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Ingår i: Eros, philia, agape. - Lund : Ellerströms förlag. - 9789172475854 ; , s. 9-22
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
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| 10. |
- Björkman, John, 1978-
(författare)
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"Må de herrskande klasserna darra" : Radikal retorik och reaktion i Stockholms press, 1848-1851
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation explores the formation of the modern historiography of class in mid-nineteenth century Sweden by analyzing constitutive rhetoric of class in the Stockholm press from 1848 to 1851. The aim is to study how disparaged workers during the February Revolution in France began to be ascribed a new kind of unified agency, and how workers in Stockholm became recipients of mobilizing appeals from all parts of the political spectrum. To this end the dissertation examines periodical papers representing the three major political positions of the period, i.e. a royalist conservative press, liberal papers in opposition, and a newly emerging socialist press. How were workers described, invoked and addressed as a new kind of community of political interest and action in these publications?Refuting perspectives of socio-economic determinism, this study adopts a conception of belonging and agency that views political communities as discursively produced by the creation of subject positions and the interpellation of individuals to them. The study is also influenced by recent re-evaluations of the category of the event associated with poststructuralism, and analyzes operations of constitutive rhetoric in forming a new symbolic field of class identity and agency in an open-ended and multivalent historical situation.The analysis shows how workers were construed as political agents in the Stockholm press during the mid-nineteenth century turmoil by being described, invoked and addressed within the framework of four main rival narratives. The socialist press tried to evoke a self-organizing working class within a collectivist narrative of labour’s liberation and universal male suffrage. The liberal press interpellated workers to a position aligned with the reformist middle class within a narrative of individual self-determination and gradual improvement. The royalist narrative of reconciliation was aimed at separating the large mass of workers from socialist and communist ideologues, deemed as mischievous outsiders, while at the same time offering them a new-found and prominent role as protectors of social harmony and peace. Only within the royalist narrative of catastrophe were the workers continuously excluded from mobilizing appeals, instead being invoked as the harbingers of an approaching communist revolution, against which all other sections of society should unite.
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