| 1. |
- Biurrun, Idoia, et al.
(författare)
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Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
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Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
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Tidskriftsartikel (refereegranskat)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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| 2. |
- Slancarova, Veronika, et al.
(författare)
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Evolution of sex determination systems with heterogametic males and females in silene.
- 2013
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Ingår i: Evolution; international journal of organic evolution. - : Wiley. - 1558-5646. ; 67:12, s. 3669-77
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Tidskriftsartikel (refereegranskat)abstract
- The plant genus Silene has become a model for evolutionary studies of sex chromosomes and sex-determining mechanisms. A recent study performed in Silene colpophylla showed that dioecy and the sex chromosomes in this species evolved independently from those in Silene latifolia, the most widely studied dioecious Silene species. The results of this study show that the sex-determining system in Silene otites, a species related to S.colpophylla, is based on female heterogamety, a sex determination system that is unique among the Silene species studied to date. Our phylogenetic data support the placing of S.otites and S.colpophylla in the subsection Otites and the analysis of ancestral states suggests that the most recent common ancestor of S.otites and S.colpophylla was most probably dioecious. These observations imply that a switch from XX/XY sex determination to a ZZ/ZW system (or vice versa) occurred in the subsection Otites. This is the first report of two different types of heterogamety within one plant genus of this mostly nondioecious plant family.
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| 3. |
- Danihelka, Jiri, et al.
(författare)
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Viola montana and V. persicifolia (Violaceae): Two names to be rejected
- 2010
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Ingår i: Taxon. - 0040-0262. ; 59:6, s. 1869-1878
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Tidskriftsartikel (refereegranskat)abstract
- The taxonomic and nomenclatural histories of Viola elatior Fr. (1828), V. pumila Chaix (1785) and V. stagnina Kit. ex Schult. (1814) in central and western Europe are discussed. The names V. stagnina and V elatior are lectotypified with specimens corresponding to the current use of these names. The neglected lectotypification in 1988 of V. montana L. (1753) with a specimen referable to V elatior is briefly reviewed. The name V persicifolia Schreb. (1771), used in some floras instead of V. stagnina, is analysed in detail, and we conclude that this name should be interpreted as referring also to V. elatior. In addition the types of V. hornemanniana Schult. (1819) and V. stipulacea Hartm. (1820) are conspecific with V. elatior. The use of V. persicifolia and V montana, representing earlier legitimate names for the species widely known as V elatior, has been notoriously confused for two centuries, and we herein recommend these two names for rejection in order to assure nomenclatural clarity and stability. For similar reasons, we recommend conservation of V. elatior against V. hornemanniana and V. stipulacea.
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| 4. |
- Eckstein, Rolf Lutz, et al.
(författare)
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Biological flora of central Europe : Viola elatior, V. pumila and V. stagnina
- 2006
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Ingår i: Perspectives in plant ecology, evolution and systematics. - : Elsevier BV. - 1433-8319 .- 1618-0437. ; 8:1, s. 45-66
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Forskningsöversikt (refereegranskat)abstract
- Viola elatior, V pumila and V stagnina (syn. V persicifolia) are very rare in central and western Europe and red-listed in many central European countries. To improve their conservation and to base management efforts on sound scientific knowledge, we here review the available information on their biology. A comparative approach is adopted to identify similarities and differences between the species. Special emphasis will be on taxonomy, community ecology and population biology. All three species belong to the section Viola, subsection Rostratae. Since they are morphologically rather similar and have often been misidentified, we supply the most important characters for separating the three taxa. The species share a continental distribution with a centre of occurrence in the temperate zone of eastern Europe and western Siberia, and reach their western range margin in central and western Europe. They have become rare and endangered through melioration and fragmentation of their habitats. All three species are iteroparous hemicryptophytes with a complex life cycle, a mixed mating system with chasmogamous and cleistogamous flowers, and a persistent seed bank. Viola pumila and V. stagnina occur in floodplain meadows and wet grasslands, whereas V. elatior is a typical species of alluvial woodland fringes and other ecotonal habitats bordering floodplain meadows. Viola elatior and V pumila are confined to calcareous or at least base-rich substrates, whereas V stagnina may also occur on strongly acidic soils. The violets are able to occupy a broad range of site conditions in terms of soil nutrient status and productivity. However, on fertile sites the species depend on regular disturbances that weaken competitors and enhance the germination of dormant seeds. Current information about mycorrhizal colonisation, biochemical and physiological data, and herbivores and pathogens is scarce or lacking, probably due to the rarity of the three species in central Europe. (c) 2006 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved.
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| 5. |
- Eckstein, Rolf Lutz, et al.
(författare)
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Variation in life-cycle between three rare and endangered floodplain violets in two regions : implications for population viability and conservation
- 2009
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Ingår i: Biologia. - : Springer Science and Business Media LLC. - 0006-3088 .- 1336-9563. ; 64:1, s. 69-80
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Tidskriftsartikel (refereegranskat)abstract
- We studied the demography of Viola elatior, V. pumila, and V. stagnina, three rare and endangered Central European floodplain species, to (i) analyse variation in life-cycles among congeners and between regions (Dyje-Morava floodplains, Czech Republic; Upper Rhine, Germany), (ii) to define sensitive stages in the life-cycles, and (iii) to identify possible threats for population viability and species conservation. Matrix models were based on the fate of marked individuals from a total of 27 populations over two years. We analysed population growth rate (lambda), stage distribution, net reproductive rate (R (0)), generation time, age at first reproduction, and elasticity and calculated a life table response experiment (LTRE). Most populations were declining and lambda did not differ between species or regions during the observed interval. Despite higher probabilities for survival and flowering in the Dyje populations, R (0) was higher in the Rhine populations. Also other demographic traits showed consistent differences between regions and/or species. Complex life-cycles and large variation in lambda precluded unequivocal identification of sensitive stages or vital rates for conservation. Variation between regions may be a consequence of differences in habitat quality. Our results suggest that deterministic processes such as reduced management, succession, habitat destruction, and lack of disturbance through reduced or eliminated flooding present the strongest threat for the viability and persistence of populations of the three floodplain violets as compared with stochastic processes. However, the persistent seed bank of the species may buffer populations against environmental variation and represents a reservoir for recovery after resumption of suitable land-use management.
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| 6. |
- 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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| 7. |
- Marcussen, Thomas, 1971, et al.
(författare)
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Inferring species networks from gene trees in high-polyploid North American and Hawaiian violets (Viola, Violaceae).
- 2012
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Ingår i: Systematic biology. - : Oxford University Press (OUP). - 1076-836X .- 1063-5157. ; 61:1, s. 107-26
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Tidskriftsartikel (refereegranskat)abstract
- The phylogenies of allopolyploids take the shape of networks and cannot be adequately represented as bifurcating trees. Especially for high polyploids (i.e., organisms with more than six sets of nuclear chromosomes), the signatures of gene homoeolog loss, deep coalescence, and polyploidy may become confounded, with the result that gene trees may be congruent with more than one species network. Herein, we obtained the most parsimonious species network by objective comparison of competing scenarios involving polyploidization and homoeolog loss in a high-polyploid lineage of violets (Viola, Violaceae) mostly or entirely restricted to North America, Central America, or Hawaii. We amplified homoeologs of the low-copy nuclear gene, glucose-6-phosphate isomerase (GPI), by single-molecule polymerase chain reaction (PCR) and the chloroplast trnL-F region by conventional PCR for 51 species and subspecies. Topological incongruence among GPI homoeolog subclades, owing to deep coalescence and two instances of putative loss (or lack of detection) of homoeologs, were reconciled by applying the maximum tree topology for each subclade. The most parsimonious species network and the fossil-based calibration of the homoeolog tree favored monophyly of the high polyploids, which has resulted from allodecaploidization 9-14 Ma, involving sympatric ancestors from the extant Viola sections Chamaemelanium (diploid), Plagiostigma (paleotetraploid), and Viola (paleotetraploid). Although two of the high-polyploid lineages (Boreali-Americanae, Pedatae) remained decaploid, recurrent polyploidization with tetraploids of section Plagiostigma within the last 5 Ma has resulted in two 14-ploid lineages (Mexicanae, Nosphinium) and one 18-ploid lineage (Langsdorffianae). This implies a more complex phylogenetic and biogeographic origin of the Hawaiian violets (Nosphinium) than that previously inferred from rDNA data and illustrates the necessity of considering polyploidy in phylogenetic and biogeographic reconstruction.
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| 8. |
- Schulz, Benjamin, et al.
(författare)
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Differential role of a persistent seed bank for genetic variation in early vs. late successional stages
- 2018
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Ingår i: PLOS ONE. - San Francisco : Public library science. - 1932-6203. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Persistent seed banks are predicted to have an important impact on population genetic processes by increasing effective population size and storing past genetic diversity. Accordingly, persistent seed banks may buffer genetic effects of disturbance, fragmentation and/or selection. However, empirical studies surveying the relationship between aboveground and seed bank genetics under changing environments are scarce. Here, we compared genetic variation of aboveground and seed bank cohorts in 15 populations of the partially cleistogamous Viola elatior in two contrasting early and late successional habitats characterized by strong differences in light-availability and declining population size. Using AFLP markers, we found significantly higher aboveground than seed bank genetic diversity in early successional meadow but not in late successional woodland habitats. Moreover, individually, three of eight woodland populations even showed higher seed bank than aboveground diversity. Genetic differentiation among populations was very strong ((ST) = 0.8), but overall no significant differentiation could be detected between above ground and seed bank cohorts. Small scale spatial genetic structure was generally pronounced but was much stronger in meadow (Sp-statistic: aboveground: 0.60, seed bank: 0.32) than in woodland habitats (aboveground: 0.11; seed bank: 0.03). Our findings indicate that relative seed bank diversity (i.e. compared to aboveground diversity) increases with ongoing succession and despite decreasing population size. As corroborated by markedly lower small-scale genetic structure in late successional habitats, we suggest that the observed changes in relative seed bank diversity are driven by an increase of outcrossing rates. Persistent seed banks in Viola elatior hence will counteract effects of drift and selection, and assure a higher chance for the species' long term persistence, particularly maintaining genetic variation in declining populations of late successional habitats and thus enhancing success rates of population recovery after disturbance events.
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