| 1. |
- Graae, Bente J., et al.
(författare)
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An experimental evaluation of the arctic fox (Alopex lagopus) as a seed disperser
- 2004
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Ingår i: Arctic, Antarctic and Alpine Research. - 1938-4246 .- 1523-0430. ; 36:4, s. 468-473
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Tidskriftsartikel (refereegranskat)abstract
- Arctic foxes are evaluated as seed dispersal vectors for Greenlandic plant species through a feeding experiment with subsequent scat analysis and germination test. Seeds of 22 common species with different morphology were tested. Passage time ranged between 4 and 48 hours. No significant differences was detected in passage time for seeds with different morphology. Cerastium alpinum and Stellaria longipes had higher germination after passage through the fox’ digestive tract as compared to controls. Sibbaldia procumbens, Oxyria digyna and Silene acaulis were favoured by passage when shorter than 10 hours. Salix glauca ssp. callicarpaea, Veronica alpina, Gnaphalium norvegicum, Papaver radicatum, Ranunculus hyperboreus, Chamaenerion latifolium, Luzula parviflora and bulbils of Polygonum viviparum and Saxifraga cernua were inhibited by passage, whereas the remaining species had too low germination percentage to allow for evaluation. Species with adaptations to wind dispersal seemed particularly vulnerable to gut pasage. Arctic foxes are able to provide long-distances dispersal of seeds lacking morphological adaptations to dispersal, but for most species seeds need to be defecated within 12 hours to remain viable.
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| 2. |
- Olofsson, Johan
(författare)
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Positive and negative plant-plant interactions in two contrasting arctic-alpine plant communities
- 2004
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Ingår i: Arctic, Antarctic and Alpine research. - 1523-0430 .- 1938-4246. ; 36:4, s. 464-467
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Tidskriftsartikel (refereegranskat)abstract
- Positive interactions in alpine plant communities have been reported to increase in importance with increasing altitude and exposure. Positive and negative interactions between plants might occur simultaneously, so the net plant-plant interaction is determined by the balance between positive and negative effects. I investigated the relative effect of facilitation and resource competition by surrounding dwarf shrubs on Carex bigelowii in two contrasting arctic-alpine tundra heathlands. Carex bigelowii was positively associated with dwarf shrubs on an exposed mountain ridge but negatively associated with dwarf shrubs on a protected heath. A removal experiment indicated that positive associations at the exposed site are the result of facilitation of C. bigelowii by the dwarf shrub canopy. Our understanding of arctic and alpine plant communities can be enhanced by regarding plant interactions as combinations of positive and negative components.
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| 3. |
- Beylich, AA
(författare)
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Geomorphology, sediment budget, and relief development in Austdalur, Austfiroir, East Iceland
- 2000
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Ingår i: ARCTIC ANTARCTIC AND ALPINE RESEARCH. - : INST ARCTIC ALPINE RES. - 1523-0430. ; 32:4, s. 466-477
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Tidskriftsartikel (refereegranskat)abstract
- This process-geomorphological study analyzes the present sediment budget in a subarctic oceanic periglacial environment in East Iceland. By a combined investigation of slope denudation and streamwork in the Austdalur drainage basin (23 km(2)), located in
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| 4. |
- Cooper EJ, Wookey PA
(författare)
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Floral Herbivory of Dryas octopetala by Svalbard Reindeer
- 2003
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Ingår i: Arctic, Antarctic, and Alpine Research. - : Regents of the University of Colorado, Boulder, CO. - 1523-0430. ; 35:3, s. 369-376
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Tidskriftsartikel (refereegranskat)abstract
- In polar semidesert communities of northwest Spitsbergen the reproductive potential of keystone vascular plant species, such as Dryas octopetala, is currently being constrained by low summer temperatures, resulting in the infrequent production of viable s
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| 5. |
- Hock, R, et al.
(författare)
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Modeling climate conditions required for glacier formation in cirques of the Rassepautasjtjakka massif, northern Sweden
- 2002
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Ingår i: Arctic, Antarctic and Alpine Research. - 1938-4246. ; 34:1, s. 3-11
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Tidskriftsartikel (refereegranskat)abstract
- Timing of cirque formation and the climate necessary to initiate glaciation are fundamental to the understanding of the landscape of the northern Scandinavian mountains. Empty cirques in the Rassepautasjtjakka massif are located near a glaciated area and thus appear near the glaciation limit. In order to investigate the climate conditions necessary for glacier formation in the cirques, we applied a spatially distributed temperature index melt model. After calibration under present climate conditions, the model was run with different combinations of increased initial winter snow cover and lowered summer air temperatures to assess the climate conditions needed for snow to survive summer and hence form a base for glaciation. Results indicate that a significant increase in precipitation or decrease in summer air temperature or a combination of both is necessary to initiate glaciation. Thus current climate conditions are far from favorable for glaciation. If summer temperature is decreased by 4degreesC or winter snow cover is more than doubled, only 10% of cirque areas remain snow covered, which is considered as a minimum condition for glacier formation. According to climate reconstructions such conditions have not occurred during the Holocene suggesting that the cirques have not been glaciated during this period. Consequently glaciation of the cirques must have occurred during other parts of the glacial cycles.
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| 6. |
- Ingolfsson, O, et al.
(författare)
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Glacial and climate history of the Antarctic Peninsula since the Last Glacial Maximum
- 2003
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Ingår i: Arctic, Antarctic and Alpine Research. - 1938-4246. ; 35:2, s. 175-186
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Forskningsöversikt (refereegranskat)abstract
- During the Last Glacial Maximum (LGM), ice thickened considerably and expanded toward the outer continental shelf around the Antarctic Peninsula. Deglaciation occurred between >14 ka BP and ca. 6 ka BP, when interglacial climate was established in the region. Deglaciation of some local sites was as recent as 4-3 ka BP. After a climate optimum, peaking ca. 4-3 ka BP, a distinct climate cooling occurred. It is characterized at a number of sites by expanding glaciers and ice shelves. Rapid warming during the past 50 yr may be causing instability of some Antarctic Peninsula ice shelves. Detailed reconstructions of the glacial and climatic history of the Antarctic Peninsula since LGM are hampered by scarcity of available archives, low resolution of many datasets, and problems in dating samples. Consequently, the configuration of LGM ice sheets, pattern of subsequent deglaciation, and environmental changes are poorly constrained both temporally and spatially.
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| 7. |
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| 8. |
- Wookey PA, Bol, RA, Caseldine CJ, Harkness DD
(författare)
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Surface age, ecosystem development, and C isotope signatures of respired CO2 in an alpine environment, north Iceland
- 2002
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Ingår i: Arctic, Antarctic, and Alpine Research. - 1523-0430. ; 34, s. 76-87
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Tidskriftsartikel (refereegranskat)abstract
- We studied the late Holocene foreland and adjacent unglaciated terrain of a small cirque glacier system in north Iceland to explore the relationship between soil/surface age, vegetation and soil evolution, and C isotope signatures of respired CO2. Field-b
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