A5064504720- Botany and Plant Ecology Studies
- Botany, Ecology, and Taxonomy Studies
- Genetic diversity and population structure
- Plant Taxonomy and Phylogenetics
- Ecology and Vegetation Dynamics Studies
- Lichen and fungal ecology
- Rangeland and Wildlife Management
- Plant Diversity and Evolution
- Plant Ecology and Taxonomy Studies
- Species Distribution and Climate Change
- Bryophyte Studies and Records
- Plant Parasitism and Resistance
- Climate change and permafrost
- Plant and Fungal Species Descriptions
- Plant Pathogens and Resistance
- Geology and Paleoclimatology Research
- Forest Ecology and Biodiversity Studies
- Mediterranean and Iberian flora and fauna
- Botanical Studies and Applications
- Plant and animal studies
- Peatlands and Wetlands Ecology
- Archaeology and Natural History
- Chromosomal and Genetic Variations
- Turfgrass Adaptation and Management
- Environmental DNA in Biodiversity Studies
University of Oslo
2008-2021
University of Maryland, College Park
2008
American Museum of Natural History
2006-2008
German Oceanographic Museum
2004
Natural History Museum
2004
UiT The Arctic University of Norway
1978-1984
The Arctic is an excellent model system for the study of polyploidy. It one Earth's most polyploid-rich areas, in particular high-level and recently evolved polyploids. Here we re-address previous hypotheses on arctic polyploidy based a new analysis circumarctic flora, review recent molecular, cytological reproductive studies. frequency level strongly increase northwards within Arctic. We found no clear-cut association between degree glaciation flora as whole, which contains many widespread...
Abstract Up to the 1960s, there was nearly complete consensus that disjunctions and endemism in North Atlantic cannot be explained without situ survival during glaciations (the "nunatak hypothesis"). The alternative " tabula rasa hypothesis" of postglacial immigration regarded merely historical interest. Herein we review recent geological, molecular, taxonomic, biogeographic data re‐examine this view. There is now strong geological evidence for some ice‐free areas within maximum limits Late...
Palaeoenvironments and former climates are typically inferred from pollen macrofossil records. This approach is time-consuming suffers low taxonomic resolution biased taxon sampling. Here, we test an alternative DNA-based utilizing the P6 loop in chloroplast trnL (UAA) intron; a short (13-158 bp) variable region with highly conserved flanking sequences. For reference, whole intron sequence database was constructed recently collected material of 842 species, representing all widespread and/or...
Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, test whether five islands is associated with distance, island size traits. Most colonized postglacially via multiple events from several source regions situated 280 >3000 km away, often not closest ones. A strong was observed insect-pollinated mixed maters, it increased distance decreased in accordance...
The biogeography and phylogeny of Cardamine L. were inferred based on sequences the nuclear ribosomal ITS regions plastid trnL intron trnL-F spacer regions. This genus is one largest polyploid-rich genera Brassicaceae has its center diversity in Eurasia. Species included from all populated continents, representing sections except two monotypic ones. results support a hypothesis recent rapid speciation genus. traditional sectional classification was not supported. We found evidence for...
Abstract Papaver alpinum s.l. is an extraordinarily polymorphic taxon distributed throughout southern and central European mountain ranges. We tested previous hypotheses about relationships taxonomical status of the numerous described taxa within this species or group by applying different molecular approaches. In addition we reevaluated morphological characters used in taxonomic treatments light results. The ancestral sequence haplotypes were widespread dominant Alps, whereas peripheral...
Paradoxically, several of the ecologically most important plant groups in Arctic are little understood terms taxonomy and biogeographic history. The circumpolar Carex bigelowii s. l. (Cyperaceae) is abundant one complicated arctic groups. While its ecology population genetics have been extensively studied, largely unexplored. We analyzed large-scale geographical structuring amplified fragment length polymorphisms (AFLPs) covering distribution range. detected high levels genetic variation,...
Increased human activity and climate change are expected to increase the numbers impact of alien species in Arctic, but knowledge is poor most Arctic regions. Through field investigations over last 10 years, review vascular plant records for high Archipelago Svalbard past 130 we explored long term trends persistence phenology. In total, 448 observations 105 taxa have been recorded from 28 sites. Recent surveys at 18 these sites revealed that had disappeared half them. Investigations a...
Phylogenetic relationships and biogeography of the genus Cerastium were studied using sequences three noncoding plastid DNA regions (trnL intron, trnL-trnF spacer, psbA-trnH spacer). A total 57 taxa was analyzed two species putative sister Stellaria as outgroups. Maximum parsimony analyses identified four clades that largely corresponded to previously recognized infrageneric groups. The results suggest an Old World origin at least migration events into North America from World. first event...
:In order to assess the influence of experimental warming on individual species response, composition and richness, abundance ramets in a wet late-melting snowbed, we established 20 open-top chambers (OTCs) permanently for 5 y (six growing seasons) at Finse, southwest Norway. Salix herbacea, Saxifraga stellaris, Omalotheca supina, Cerastium cerastoides, Epilobium anagallidifolium increased experimentally warmed plots, while there was no significant response Carex lachenalii, Deschampsia...
The generic ecological impact assessment of alien species (GEIAA) is described. It comprises a set criteria and an procedure. consists three that quantify invasion potential, six capture the effects species. threshold values for all are numerically defined, rendering fully quantitative. Genericity ensured by using applicable to taxonomic groups in habitats. In being generic, quantitative, normatively neutral, were inspired international Red List criteria. Capturing both potential effect,...
We developed a combined molecular and morphological approach to unravel complex variation at low taxonomic levels, exemplified by some arctic members of Potentilla. Twenty-one populations from Svalbard were analyzed for random amplified polymorphic DNAs (RAPDs) 64 characters test the hypotheses that (1) P. nivea (section Niveae) consists three taxa (P. chamissonis, insularis, nivea), (2) "eco-morphotypes" in pulchella Multifidae) should be considered different taxa, (3) insularis originated...
Abstract In many arctic-alpine plant groups, reticulate evolutionary histories have resulted in problems with species delimitation and phylogenetic reconstruction. the Saxifraga rivularis complex (2n = 26, 52), number of accepted ranges from a single polymorphic one (S. s.l.) to several (the circumpolar S. hyperborea, amphi-Atlantic rivularis, three amphi-Pacific bracteata, flexuosa, arctolitoralis, debilis Rocky Mountains). A combination molecular (AFLPs), flow cytometrical, morphological...
Abstract Polyploidy, probably the single most important mode of sympatric speciation in plants, tends to result complicated evolutionary patterns. The Cardamine digitata aggregate is a species complex where polyploidy has resulted taxonomic and nomenclatural controversies. Two basic chromosome numbers are found ( x = 7 8), all plants studied so far tetra‐ dodecaploids. We used six microsatellite loci originally developed for Arabidopsis genome identify units within C. aggregate, obtaining...
Summary Brysting, A. K. & Elven, R.: The Cerastium alpinum‐C. arcticum complex (Caryophyllaceae): numerical analyses of morphological variation and a taxonomic revision C. Lange s.l. – Taxon 49: 189–216. 2000. ISSN 0040‐0262. Morphological alpinum L., Lange, related taxa was investigated by analyses. showed that the present division into two species is inappropriate does not cover levels within complex. Two alternative models for new functional taxonomy are discussed: (1) there one...
Plant remains have been found on ground recently deglaciated from the Omnsbreen glacier. They consist of Salix herbacea, spp., Silene acaulis, Polytrichum norvegicum, Kiaeria of. starkei, and some unidentified species. Their age has determined by radiocarbon method to approx. 550 years, indicating that present glacier emerged as late clima deterioration in Middle Ages. The past vegetation was similar present, but slightly more thermophilous, a rapid fourteenth century.
Small, isolated and/or peripheral populations are expected to harbour low levels of genetic variation and may therefore have reduced adaptability environmental change, including climate warming. In the Arctic, global warming has already caused vegetation change across region is acting as a significant stressor on Arctic biodiversity. Many rare plants in relicts from early Holocene warm periods, but their ability benefit current dependent viability populations. We examined Amplified Fragment...
Abstract 1 . Due to globalisation, trade and transport, the spread of alien species is increasing dramatically. Some become ecologically harmful by threatening native biota. This can lead irreversible changes in local biodiversity ecosystem functioning, and, ultimately, biotic homogenisation. 2 We risk‐assessed all plants, animals, fungi algae, within certain delimitations, that are known reproduce Norway. Mainland Norway Arctic archipelago Svalbard plus Jan Mayen were treated as separate...