| 1. |
- Schofield, J. Edward, et al.
(författare)
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Pushing the Limits : Palynological Investigations at the Margin of the Greenland Ice Sheet in the Norse Western Settlement
- 2022
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Ingår i: Environmental Archaeology. - : Routledge. - 1461-4103 .- 1749-6314. ; 27:2, s. 228-242
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents two high-resolution pollen records dating to ?AD 1000?1400 that reveal the impacts of Norse colonists on vegetation and landscape around a remote farmstead in the Western Settlement of Greenland. The study is centred upon a ?centralised farm? (ruin group V53d) in Austmannadalen, near the margin of the Greenland Ice Sheet (64?13?N, 49?49?W). The climate is low arctic and considered marginal in terms of its suitability for the type of pastoral agriculture that the Norse settlers introduced. The data reveal that at a short distance (?500?m) from the farm buildings, the palynological ?footprint? for settlement becomes extremely indistinct, the only clear palaeoenvironmental evidence for a human presence being elevated levels of microscopic charcoal. This contrasts with the Eastern Settlement, where a strong palynological signature for Norse landn?m is evident, from the local (individual farm) through to the regional (landscape) scale. The palynological data from Austmannadalen, and the Western Settlement more generally, imply that farming occurred at very low intensity. This aligns with ideas that promote the importance of hunting, and trade in valuable Arctic commodities (e.g. walrus ivory), ahead of a search for new pasture as the dominant motivation driving the Norse settlement of this region.
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| 2. |
- Pearce, Danni M., et al.
(författare)
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The glacial geomorphology of upper Godthabsfjord (Nuup Kangerlua) in southwest Greenland
- 2018
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Ingår i: Journal of Maps. - : Taylor & Francis. - 1744-5647. ; 14:2, s. 45-55
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Tidskriftsartikel (refereegranskat)abstract
- The Greenland Ice Sheet (GrIS) is known to have experienced widespread retreat over the last century. Information on outlet glacier dynamics, prior to this, are limited due to both a lack of observations and a paucity of mapped or mappable deglacial evidence which restricts our understanding of centennial tomillennial timescale dynamics of the GrIS. Here we present glacial geomorphological mapping, for upper Godthabsfjord, covering 5800km(2) at a scale of 1:92,000, using a combination of ASTER GDEM V2, a medium-resolution DEM (error <10m horizontal and <6m vertical accuracy), panchromatic orthophotographs and ground truthing. This work provides a detailed geomorphological assessment for the area, compiled as a single map, comprising of moraines, meltwater channels, streamlined bedrock, sediment lineations, ice-dammed lakes, trimlines, terraces, gullied sediment and marine limits. Whilst some of the landforms have been previously identified, the new information presented here improves our understanding of ice margin behaviour and can be used for future numerical modelling and landform dating programmes.Data also form the basis for palaeoglaciological reconstructions and contribute towards understanding of the centennial to millennial timescale record of this sector of the GrIS.
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| 3. |
- Peña, Viviana, et al.
(författare)
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Lithothamnion (Hapalidiales, Rhodophyta) in the changing Arctic and Subarctic : DNA sequencing of type and recent specimens provides a systematics foundation*
- 2021
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Ingår i: European journal of phycology. - : Taylor & Francis. - 0967-0262 .- 1469-4433. ; 56:4, s. 468-493
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Tidskriftsartikel (refereegranskat)abstract
- Coralline red algae in the non-geniculate genera Clathromorphum, Phymatolithon and Lithothamnion are important benthic ecosystem engineers in the photic zone of the Arctic and Subarctic. In these regions, the systematics and biogeography of Clathromorphum and Phymatolithon have mostly been resolved whereas Lithothamnion has not, until now. Seventy-three specific and infraspecific names were given to Arctic and Subarctic Lithothamnion specimens in the late 19th and early 20th century by Frans R. Kjellman and Mikael H. Foslie. DNA sequences from 36 type specimens, five historical specimens, and an extensive sampling of recent collections resulted in the recognition of four Arctic and Subarctic Lithothamnion species, L. glaciale, L. lemoineae, L. soriferum and L. tophiforme. Three genes were sequenced, two plastid-encoded, rbcL and psbA, and the mitochondrial encoded COI-5P; rbcL and COI-5P segregated L. glaciale from L. tophiforme but psbA did not. Partial rbcL sequences obtained from type collections enabled us to correctly apply the earliest available names and to correctly place the remainder in synonymy. We were unable to sequence another 22 type specimens, but all of these are more recent names than those that are now applied. It is difficult to identify these species solely on morpho-anatomy as they can all occur as encrusting corallines or as maerl (rhodoliths). We demonstrate the importance of sequencing historical type specimens by showing that the recently proposed North-east Atlantic L. erinaceum is a synonym of one of the earliest published Arctic species of Lithothamnion, L. soriferum, itself incorrectly placed in synonymy under L. tophiforme based on morpho-anatomy. Based on sequenced specimens, we update the distributions and ecology of these species.
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| 4. |
- Schoenrock, Kathryn M., et al.
(författare)
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Biodiversity of Kelp Forests and Coralline Algae Habitats in Southwestern Greenland
- 2018
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Ingår i: Diversity. - : MDPI. - 1424-2818. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- All marine communities in Greenland are experiencing rapid environmental change, and to understand the effects on those structured by seaweeds, baseline records are vital. The kelp and coralline algae habitats along Greenland's coastlines are rarely studied, and we fill this knowledge gap for the area around Nuuk, west Greenland. Using subtidal swath surveys, photo-quadrats, and grab samples, we characterised the diversity of floral and faunal assemblages in kelp forests and coralline algae beds. The most abundant herbivore assemblages and the most diverse communities occur in the interstitial habitats of rhodolith beds. In kelp forests, species diversity is higher in epi-benthic (photo-quadrat) and mid-water (swath) surveys. These habitats are not mutually exclusive; Agarum clathratum is prominent in coralline algal habitats, while crustose coralline algae cover the bedrock under kelp holdfasts. Overall, the suite of surveys used capture the diverse communities within kelp forests and coralline algae in Greenland and their differing role in the life history of the inhabitants. Furthermore, coralline algae beds are an important carbonate store, with CaCO3 concentrations ranging from 28.06 to 103.73 gm(-3). Our research sets the baseline for continued investigations and monitoring of these important habitats and their supported fisheries.
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| 5. |
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| 6. |
- Schoenrock, Kathryn M., et al.
(författare)
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Influences of salinity on the physiology and distribution of the Arctic coralline algae, Lithothamnion glaciale (Corallinales, Rhodophyta)
- 2018
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Ingår i: Journal of Phycology. - : Wiley-Blackwell. - 0022-3646 .- 1529-8817. ; 54:5, s. 690-702
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Tidskriftsartikel (refereegranskat)abstract
- In Greenland, free-living red coralline algae contribute to and dominate marine habitats along the coastline. Lithothamnion glaciale dominates coralline algae beds in many regions of the Arctic, but never in Godthabsfjord, Greenland, where Clathromorphum sp. is dominant. To investigate environmental impacts on coralline algae distribution, calcification and primary productivity were measured insitu during summers of 2015 and 2016, and annual patterns of productivity in L.glaciale were monitored in laboratory-based mesocosm experiments where temperature and salinity were manipulated to mimic high glacial melt. The results of field and cold-room measurements indicate that both L.glaciale and Clathromorphum sp. had low calcification and photosynthetic rates during the Greenland summer (2015 and 2016), with maximum of 1.225 +/- 0.17 or 0.002 +/- 0.023mol CaCO3.g(-1).h(-1) and -0.007 +/- 0.003 or -0.004 +/- 0.001mg O-2.L-1.h(-1) in each species respectively. Mesocosm experiments indicate L.glaciale is a seasonal responder; photosynthetic and calcification rates increase with annual light cycles. Furthermore, metabolic processes in L.glaciale were negatively influenced by low salinity; positive growth rates only occurred in marine treatments where individuals accumulated an average of 1.85 +/- 1.73mg.d(-1) of biomass through summer. These results indicate high freshwater input to the Godthabsfjord region may drive the low abundance of L.glaciale, and could decrease species distribution as climate change increases freshwater input to the Arctic marine system via enhanced ice sheet runoff and glacier calving.
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| 7. |
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| 8. |
- Tuya, Fernando, et al.
(författare)
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Levelling-up rhodolith-bed science to address global-scale conservation challenges
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 892
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Tidskriftsartikel (refereegranskat)abstract
- Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mitigation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp forests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and ecosystem services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.
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