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Auteur Sylvi Marlen Sandvik |
Documents disponibles écrits par cet auteur (2)
Affiner la rechercheBreeding system and effects of plant size and flowering time on reproductive success in the alpine herb Saxifraga stellaris L. / Sylvi Marlen Sandvik in Arctic and alpine research, 31 (2) (05/1999)
Titre : Breeding system and effects of plant size and flowering time on reproductive success in the alpine herb Saxifraga stellaris L. Type de document : Imprimé Auteurs : Sylvi Marlen Sandvik ; Ørjan Totland (1968-) ; J. Nylehn Année de publication : 1999 Article en page(s) : 96-201 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Pollinisateur Mots-clés : Saxifraga sp. Saxifraga stellaris L. Résumé : The pollination and reproductive ecology of Saxifraga stellaris was investigated in alpine southwest Norway. A breeding system analysis, with performance of controlled crosses, revealed that S. stellaris is self-compatible and that reproductive success after cross- and self-pollination is equal. Relative autodeposition efficiency (i.e. mean seed:ovule ratio in caged, nonmanipulated plants relative to mean seed:ovule ratio of control plants) was, however, low (0.29), suggesting that S. stellaris depends on insect visitation for maximum seed set. Seed set is not restricted by pollen availability, as indicated by a supplemental hand-pollination experiment. Plant size had a strong positive impact on ovule number, which in turn was positively correlated with seed number. Plant size also had a positive influence on seed weight. Seed weight was lowest for late-flowering plants, suggesting that shorter time for seed maturation and lower temperatures late in the season restrict seed weight. No correlations between flowering date and seed number were found, perhaps because the pollinators are relatively insensitive to temperature conditions and thus their activity does not change through the flowering season of S. stellaris. Identifiant : DOI : 10.1080/15230430.1999.12003298 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137898
in Arctic and alpine research > 31 (2) (05/1999) . - 96-201Sandvik, Sylvi Marlen, Totland, Ørjan (1968-), Nylehn, J. 1999 Breeding system and effects of plant size and flowering time on reproductive success in the alpine herb Saxifraga stellaris L. Arctic and alpine research, 31(2): 96-201.Documents numériques
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Article (1999)URL
Titre : Changes in alpine snowbed-wetland vegetation over three decades in northern Norway Type de document : Imprimé Auteurs : Sylvi Marlen Sandvik ; Arvid Odland Année de publication : 2014 Article en page(s) : 377-384 Langues : Anglais (eng) Catégories : [OIEAU-Thèmes] Habitat
[CBNPMP-Géographique] Norvège
[CBNPMP-Thématique] Changement climatiqueRésumé : We have quantified floristic changes in alpine snowbeds and wetland vegetation during three decades and analyzed to what extent these changes are related to initial variations in snow cover duration and distance to groundwater level. Vascular plant species richness and total plant cover were estimated along three transects in northern Norway. Three different vegetation zones were identified along the original transects: relatively dry snowbeds, wet snowbeds and wetlands. The resampling shows major changes in species richness and plant cover. In general, there was a net immigration of species and 13 new species were found. Five rare species with initial low cover were lost. In the dry and wet snowbeds, species richness and total plant cover increased, mostly because of invasion by shrubs, graminoids and herbs. A general trend was that species indicating high soil moisture were strongly reduced. In the wetland zones there were no significant floristic changes but hygrophilous species had decreased and were replaced by graminoids and shrub species with lower water requirements. These floristic changes were significantly related to snow and soil moisture conditions, important factors for rate and direction of change. Contrasting vegetation responses within very short distances demonstrate the importance of detailed knowledge of the actual microhabitats when effects of climate change in alpine habitats are considered.
Identifiant : DOI : 10.1111/j.1756-1051.2013.00249.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155429
in Nordic journal of botany > 32 (2014) . - 377-384Sandvik, Sylvi Marlen, Odland, Arvid 2014 Changes in alpine snowbed-wetland vegetation over three decades in northern Norway. Nordic journal of botany, 32: 377-384.Documents numériques
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