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- 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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| 2. |
- Sim, Thomas G., et al.
(författare)
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Regional variability in peatland burning at mid-to high-latitudes during the Holocene
- 2023
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Ingår i: Quaternary Science Reviews. - : Elsevier. - 0277-3791 .- 1873-457X. ; 305
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Tidskriftsartikel (refereegranskat)abstract
- Northern peatlands store globally-important amounts of carbon in the form of partly decomposed plant detritus. Drying associated with climate and land-use change may lead to increased fire frequency and severity in peatlands and the rapid loss of carbon to the atmosphere. However, our understanding of the patterns and drivers of peatland burning on an appropriate decadal to millennial timescale relies heavily on individual site-based reconstructions. For the first time, we synthesise peatland macrocharcoal re-cords from across North America, Europe, and Patagonia to reveal regional variation in peatland burning during the Holocene. We used an existing database of proximal sedimentary charcoal to represent regional burning trends in the wider landscape for each region. Long-term trends in peatland burning appear to be largely climate driven, with human activities likely having an increasing influence in the late Holocene. Warmer conditions during the Holocene Thermal Maximum (similar to 9e6 cal. ka BP) were associated with greater peatland burning in North America's Atlantic coast, southern Scandinavia and the Baltics, and Patagonia. Since the Little Ice Age, peatland burning has declined across North America and in some areas of Europe. This decline is mirrored by a decrease in wider landscape burning in some, but not all sub-regions, linked to fire-suppression policies, and landscape fragmentation caused by agricultural expansion. Peatlands demonstrate lower susceptibility to burning than the wider landscape in several instances, probably because of autogenic processes that maintain high levels of near-surface wetness even during drought. Nonetheless, widespread drying and degradation of peatlands, particularly in Europe, has likely increased their vulnerability to burning in recent centuries. Consequently, peatland restoration efforts are important to mitigate the risk of peatland fire under a changing climate. Finally, we make recommendations for future research to improve our understanding of the controls on peatland fires.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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