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Ecology of Alpine Snowbeds and the Impact of Global Change / Robert G. Björk in Arctic, Antarctic, and Alpine Research, 39 (1) (2007) 

Public Citation [article]  inArctic, Antarctic, and Alpine Research > 39 (1) (2007) . - 34-43 Titre : Ecology of Alpine Snowbeds and the Impact of Global Change Type de document : Imprimé Auteurs : Robert G. Björk ; Ulf Molau (1951-) Année de publication : 2007 Article en page(s) : 34-43 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Changement climatique Résumé : The ecosystems of alpine snowbed habitats are reviewed with emphasis on ecosystem functioning and capability to adapt to current and predicted global change. Snowbeds form in topographic depressions that accumulate large amounts of snow during the winter months, and the final snowmelt does not occur until late in the growing season. Many species preferentially grow in snowbed habitats and some of these are even restricted to these habitats. In this review we identify several ecosystem services which snowbeds provide to the alpine landscape. For instance, snowbeds provide a steady water and nutrient supply to adjacent plant communities and offer newly emerged high-quality food for herbivores late in the growing season. We also propose that alpine snowbeds are much more productive than earlier thought, especially when the very short growing season and often high grazing pressure are taken fully into account. Furthermore, we propose that bryophytes and graminoids (grasses, sedges, and rushes) probably will be most negatively impacted by global change, and the snowbed plant communities will be invaded by species from adjacent plant communities, especially by shrubs and boreal species. As snowbed plants have special growth conditions, their sensitivity and ability to respond rapidly to changes in annual snowfall patterns make snowbed communities particularly vulnerable in a warmer climate, and thereby sensitive indicators of global change. Identifiant : DOI : 10.1657/1523-0430(2007)39[34:EOASAT]2.0.CO;2 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155391 Björk, Robert G., Molau, Ulf (1951-) 2007 Ecology of Alpine Snowbeds and the Impact of Global Change. Arctic, Antarctic, and Alpine Research, 39(1): 34-43.

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Consultable article (2007) URL

Gender variation in Bartsia alpina (Scrophulariaceae), a subarctic perennial hermaphrodite / Ulf Molau in American Journal of Botany, 78 (3) (1991) 

Public Citation [article]  inAmerican Journal of Botany > 78 (3) (1991) . - 326-339 Titre : Gender variation in Bartsia alpina (Scrophulariaceae), a subarctic perennial hermaphrodite Type de document : Imprimé Auteurs : Ulf Molau (1951-) Année de publication : 1991 Article en page(s) : 326-339 Langues : Anglais (eng) Mots-clés : Nothobartsia sp. Résumé : Maternal and paternal effects on seed size and reproductive success (RS) were studied in a subarctic population of Bartsia alpina L. (Scrophulariaceae), a hemiparasitic perennial herb forming dense clones in open habitats. The impact of environmental factors was assessed in fertilization and defoliation experiments, and gender specialization of individual genets was investigated in a series of diallel experiments (reciprocal crossings) in the field. Maternal effects on seed weight were much larger than paternal effects, and seed weight was also strongly influenced by resource availability (especially nitrogen). The highest seed weights were usually found when genets were associated with Astragalus frigidus, which seems to be the optimal host species in the population, but similar results were achieved with NPK (nitrogen-phosphorus-potassium) fertilization. Defoliation experiments revealed an innate minimum seed weight, below which seed number was affected by resource deprivation. The reciprocal crossing program indicated a high level of gender specialization in individual genets (clones), ranging continuously from almost pure males to almost pure females. Early-flowering genets showed the highest average male RS, whereas female RS increased in late-flowering genets. Phenological separation of the genets into ‘early’ and ‘late’ revealed an inverse correlation between male and female performance. Numerous characters contributing to phenotypic gender were measured in the genets, but these characters and functional gender calculations from the diallel experiment were only weakly correlated. It is concluded that simultaneous measures of both male and female RS are needed for a reliable assessment of gender variation. Identifiant : DOI : 10.1002/j.1537-2197.1991.tb15195.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137906 Molau, Ulf (1951-) 1991 Gender variation in Bartsia alpina (Scrophulariaceae), a subarctic perennial hermaphrodite. American Journal of Botany, 78(3): 326-339.

Documents numériques

Consultable article (1991) URL

Generalization of heterogeneous alpine vegetation in air photo-based image classificaiton, Latnjajaure catchment, northern sweden / K.E.M. Lindblad in Pirineos. Revista de Ecología de Montaña, 161 (2006)

Public Citation [article]  inPirineos. Revista de Ecología de Montaña > 161 (2006) . - 3-32 Titre : Generalization of heterogeneous alpine vegetation in air photo-based image classificaiton, Latnjajaure catchment, northern sweden Type de document : Imprimé Auteurs : K.E.M. Lindblad ; R Nyberg ; Ulf Molau (1951-) Année de publication : 2006 Article en page(s) : 3-32 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Cartographies phytosociologiques [CBNPMP-Thématique] Télédétection Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=139675 Lindblad, K.E.M., Nyberg, R, Molau, Ulf (1951-) 2006 Generalization of heterogeneous alpine vegetation in air photo-based image classificaiton, Latnjajaure catchment, northern sweden. Pirineos. Revista de Ecología de Montaña, 161: 3-32.

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
R4459	P-184	Revue	Centre de documentation	Revues	Consultable

Reproductive ecology of Saxifraga oppositifolia : phenology, mating system, and reproductive success / M. Stenstrom in Arctic and alpine research, 24 (4) (1992) 

Public Citation [article]  inArctic and alpine research > 24 (4) (1992) . - 337-343 Titre : Reproductive ecology of Saxifraga oppositifolia : phenology, mating system, and reproductive success Type de document : Imprimé Auteurs : M. Stenstrom ; Ulf Molau (1951-) Année de publication : 1992 Article en page(s) : 337-343 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phénologie Mots-clés : Saxifraga sp.  Saxifraga oppositifolia L. Résumé : We studied the reproductive biology in Saxifraga oppositifolia L. (Saxifragaceae) at a subarctic-alpine tundra site at Latnjajaure Field Station, North Swedish Lapland. Saxifraga oppositifolia is a perennial herb with circumpolar distribution, and it is one of the earliest flowering species in its habitats. Late-flowering genets were found to have accelerated phenology; this was correlated with heat acumulation per day. Individual flowers were found to last for 11.7 d. Strongly protogynous flowers (female phase lasted 4.2 d), declining stigma receptivity at the time of anther dehiscence, and more or less simultaneous flowering within genets reduce the probability for self-pollination. High seed abortion in naturally pollinated flowers (seed:ovule ratio = 0.25) supports this prediction. Crossing experiments showed that seed set is very low from autodeposition of pollen, and almost as low from selling. Reproductive success was found to be pollen limited. Identifiant : DOI : 10.1080/00040851.1992.12002966 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137889 Stenstrom, M., Molau, Ulf (1951-) 1992 Reproductive ecology of Saxifraga oppositifolia : phenology, mating system, and reproductive success. Arctic and alpine research, 24(4): 337-343.

Documents numériques

Consultable Article (1992) URL