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- Dítě, Daniel, et al.
(författare)
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Glacial-relict symptoms in the Western Carpathian flora
- 2018
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Ingår i: Folia Geobotanica. - : Springer Science and Business Media LLC. - 1211-9520 .- 1874-9348. ; 53, s. 277-300
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Tidskriftsartikel (refereegranskat)abstract
- Glacial relicts have been regionally morecommon in glacial than in recent times. A rigorousassessment of which species are indeed glacial relictsis extremely difficult because direct evidence is untraceableor equivocal for many species.We aimed to identifyspecies of theWestern Carpathian flora (vascular plants,bryophytes and terrestrial lichens) that display apparentbiogeographical and ecological symptoms, suggesting awider regional or supra-regional distribution during glacialtimes, or at least before the middle-Holoceneclimate optimum. We worked with the premise thatexemplary relict species should tolerate continentaland/or arctic climates, should have large distributionranges with disjunctions, being regionally rare and ecologicallyconservative nowadays, should be associatedwith habitats that occurred during glacial times (tundra,steppe, peatland, open coniferous forest) and shoulddisplay a restriction of ecological niches in the studyregion. The assessed species were primarily those withboreo-continental or artcic-alpine distribution.We demonstrateda conspicuous gradient of glacial-relict symptoms,with Carex vaginata, Betula nana, Trichophorumpumilum, Nephroma arcticum, Saxifraga hirculus andCladonia stellaris topping the ranking. Based on thearbitrary ranking, 289 taxa can be considered highprobabilityrelicts. For only a minority of them, thereare any phylogeographical and/or palaeoecological dataavailable from the study area. Biogeographical and ecologicalsymptoms of 144 taxa suggest that they retreatedrapidly after the Last Glacial Maximum whereas otherspecies probably retreated later. The first principal componentof biogeographical symptoms sorted speciesfrom circumpolar arctic-alpine species of acidicpeatlands and wet tundra to strongly continental speciesof steppe, steppe-tundra and mineral-rich fens. Thisdifferentiation may mirror the altitudinal zonation ofglacial vegetation in the Western Carpathians.
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| 2. |
- Jiroušek, Martin, et al.
(författare)
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Classification of European bog vegetation of the Oxycocco‐Sphagnetea class
- 2022
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Ingår i: Applied Vegetation Science. - : Wiley. - 1402-2001 .- 1654-109X. ; 25:1, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Classification of European bog vegetation (Oxycocco- Sphagnetea class); iden -tification of diagnostic species for the class and vegetation subgroups (orders and alliances); development of an expert system for automatic classification of vegetation plots; and production of distribution maps of the Oxycocco- Sphagnetea class and its alliances.Location: Europe.Methods: A data set of vegetation- plot records was compiled to include various bog types over most of the European continent. An unsupervised classification (beta- flexible linkage method, Sørensen distance measure) and detrended correspondenceanalysis (DCA) ordination were applied. Formal definitions of syntaxa based on spe -cies presence and covers, and respecting the results of the unsupervised classifica-tion, were developed and included in a classification expert system.Results: The Oxycocco- Sphagnetea class, its two orders (Sphagno- Ericetalia tetralicisand Sphagnetalia medii) and seven compositionally distinct alliances were formally de -fined. In addition to the syntaxa included in EuroVegChecklist, three new alliances were distinguished: Rubo chamaemori- Dicranion elongati (subarctic polygon and palsa mires); Erico mackaianae- Sphagnion papillosi (blanket bogs of the northwestern IberianPeninsula); and Sphagno baltici- Trichophorion cespitosi (boreal bog lawns). The latter alliance is newly described in this article.Conclusions: This first pan- European formalized classification of European bog veg -etation partially followed the system presented in EuroVegChecklist, but suggested three additional alliances. One covers palsa and polygon mires, one covers Iberian bogs with endemics and one fills the syntaxonomical gap for lawn microhabitats in boreal bogs. A classification expert system has been developed, which allows assign -ment of vegetation plots to the types described.
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