| 1. |
- Aymard, Gerardo A., et al.
(författare)
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Polygalaceae
- 2004
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Ingår i: Flora of the Venezuelan Guayana. - St. Louis : Missouri Botanical Garden Press. - 1930723369 ; , s. 316-347, s. 306-308
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Eriksen, Bente, 1960, et al.
(författare)
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Polygalaceae
- 2006
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Ingår i: The families and genera of vascular plants. - Heidelberg : Springer. ; , s. 345-363
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Molau, Ulf, 1951, et al.
(författare)
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Onset of flowering and climate variability in an alpine landscape: A 10-year study from Swedish Lapland
- 2005
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Ingår i: American Journal of Botany. - 0002-9122. ; 92:3, s. 422-431
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Tidskriftsartikel (refereegranskat)abstract
- Long-term studies on phenology are rarely reported from arctic and alpine areas, but are essential for understanding biotic and abiotic controls on flowering. We monitored first flowering day (FFD) for 144 species in a subarctic-alpine area in Swedish Lapland over a period of 10 yr (1992-2001). Temperature and global radiation were monitored continuously, and snowcover duration was observed. Thawing degree-days and snowcover duration (exposure) were the dominant environmental controls on phenology. We introduce a lability index (LI) to describe the interannual variability in FFD among species. The temporal sequence of species is very constant among years, although a few species are more labile. The species were also classified into the catagories "Functional type," "Raunkiaer's life form," and "Sorensen's wintering floral type." The last two reflected the environmental data best, and together with "Exposure" they were combined into a phenology index (PI). The index was subsequently used in a triangular ordination together with FFD. The ordination illustrates whether species flower earlier or later than expected from their preconditions. We hypothesize that species having a delayed flowering respond more readily to global warming than species having an already optimized flowering.
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| 4. |
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| 5. |
- Persson, Claes, 1960, et al.
(författare)
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Three new species of Valeriana (Valerianoideae, Caprifoliaceae) from southern Ecuador
- 2023
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Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 579:1, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- Three new species of Valeriana from southern Ecuador are described and illustrated. Valeriana plateadensis is found near the highest peak of Cerro Plateado in Cordillera del Cóndor at 2900 m a.s.l. and is recognized by the shrubby habit and sessile, densely imbricate, spatulate leaves and 3-lobed corollas. V. yacuriensis is found near Lagunas Negras de Jimbura in the Parque Nacional Yacurí at 3500 m a.s.l. and is recognized by the shrubby habit, petiolate leaves and 3-lobed corollas. V. xenophylloides is found in the Páramo de Patococha at 3400 m a.s.l. and is recognized by its cushion growth form, the crown of trichomes at the leaf apex and 3-lobed corollas.
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| 6. |
- Bochenek, Grazyna, 1977, et al.
(författare)
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Annual growth of male and female individuals of the Common Ash (Fraxinus excelsior L.)
- 2010
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Ingår i: Plant Ecology and Diversity. - : Informa UK Limited. - 1755-0874 .- 1755-1668. ; 3:1, s. 47-57
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Tidskriftsartikel (refereegranskat)abstract
- Background: In general, females of woody dioecious plants are expected to grow more slowly than males because of the high cost associated with fruit bearing. Yet wind-pollinated species may invest relatively heavily in male reproduction, and various compensatory mechanisms can offset incurred costs, therefore the apparent growth of genders might be similar over a longer period of time. Any cost-related disparities are expected to be most pronounced in mast flowering years, when female reproductive resource demand is highest. Aims: We aimed to investigate gender-related response in relation to the cost of reproduction, and as a function of climate. Methods: Using dendrochronology techniques and analysing growth parameters at the branch level, we compared long-term and seasonal growth of male and female Fraxinus excelsior trees. Results: There was no observed decline in trunk growth of either of the genders over a 55-year period, but male and female trees had distinguishable annual growth patterns. The tree-ring widths of both genders were smaller in masting years than in other years. The difference between genders could be explained by their response to different climatic variables: females are more sensitive to spring frost and drought in early summer, while male growth depends more on late summer conditions. Conclusions: Vegetative development and flowering create a feedback system that minimises the cost of reproduction and assures that expenses are covered. Hence, growth differences between genders may be related to their phenological and physiological disparities rather than reproductive cost differences per se.
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| 7. |
- Bochenek, Grazyna, 1977, et al.
(författare)
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First Come, First Served: Delayed Fertilization Does Not Enhance Pollen Competition in a Wind-Pollinated Tree, Fraxinus excelsior L. (Oleaceae)
- 2011
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Ingår i: International Journal of Plant Sciences. ; 172:1, s. 60-69
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Tidskriftsartikel (refereegranskat)abstract
- Under natural conditions pollen vectors act stochastically, and the order in which pollen arrives can influence seed paternity. In a number of wind-pollinated taxa, however, fertilization does not occur immediately. It has been proposed that delayed fertilization promotes pollen competition by providing a “fair start” for pollen tubes. To test this hypothesis we compared paternity after simultaneous and consecutive pollinations with multiple donors in Fraxinus excelsior. Additionally, we investigated pollen tube growth in naturally pollinated flowers. Under natural conditions pollen grains arrived on the stigma one by one, and their mean number reached 6 after 10 d of anthesis. A pollen tube from the first-arriving pollen grain entered the style after 24 h and reached the base on the second day following pollination. Fertilization by nuclei from the same first-arriving pollen tube occurred after stigma necrosis about 3 wk later. Paternity tests confirmed that pollen applied first in the experimental pollinations had an overwhelming advantage over pollen applied 24 h later. As delayed fertilization does not play a role in prezygotic selection in this species, flowering phenology might be more important for paternity success than pollen tube growth performance.
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| 8. |
- Eriksen, Bente, 1960
(författare)
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Beringia – en tillflyktsort för växter och djur
- 2008
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Ingår i: Ymer. - 0044-0477. ; 2007:127, s. 99-111
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Området kring Berings Sund, som var isfritt under senaste nedisningen, ges av den svenske botanisten Eric Hultén 1937 namnet Beringia. Han uppställer en hypotes om att Beringia har utgjort ett refugium för arktiska växter och djur varifrån arterna sedan koloniserade övriga Arktis allt eftersom isen drog sig tillbaka. Med hjälp av molekylär teknik är det idag möjligt att testa om hypotesen kring den arktiska florans historia och evolution är sann.
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| 9. |
- Eriksen, Bente, 1960
(författare)
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Clementin eller mandarin?
- 2010
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Ingår i: Kaskelot. - 0106-0023. ; 184, s. 30-35
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Supermarkedets hylder bugner af citrusfrugter. De findes i farver fra grønne til gule og orange og i størrelser fra fugleæg til håndbolde. Hvis du er forvirret over alle sorter og navne, er det ikke så mærkeligt. Men i virkeligheden har vi kun at gøre med få vilde arter. Resten af vores citrusfrugter er med enkelte undtagelser opstået dom krydsninger mellem dem.
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| 10. |
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