Philopatry influences animal distribution and can lead to a kinship-based spatial structure, where proximity and relatedness are tightly linked. In the Barents Sea region, polar bears (Ursus maritimus) of the coastal ecotype remain year-round within the Svalbard archipelago. This coastal strategy is thought to be stable across years; however, little is known about the intra-individual variability in site fidelity or the influence of kinship on space use. Using high-resolution GPS telemetry, we looked at multi-year philopatry among 17 coastal female polar bears over eight years (2011–19) and investigated whether it is linked to the females’ degree of kinship. Individuals showed a stable space use in both consecutive and non-consecutive years. Yearly individual home ranges (HRs) overlapped, on average, by 44% (range: 9–96%), and their centroids were, on average, 15 km (range: 2–63 km) apart. The space use of related females revealed a year-round strong female kin structure. Annual HRs of related females overlapped, on average, by 24% (range: 0–66%), and their centroids were, on average, 18 km (range: 2–52 km) apart. In contrast, non-related females had much larger distances between centroids (average: 160 km, range: 59–283 km). Additionally, females showed a great site fidelity in all seasons: individual seasonal HR centroids were, on average, less than 30 km (range: 1.8–172 km) apart. Bears in this region seem to exhibit a stronger site fidelity than those reported from other parts of the species range. These findings also highlight the importance of maternal learning in space use.
{"title":"Stability of space use in Svalbard coastal female polar bears: intra-individual variability and influence of kinship","authors":"C. Brun","doi":"10.33265/POLAR.V40.5355","DOIUrl":"https://doi.org/10.33265/POLAR.V40.5355","url":null,"abstract":"Philopatry influences animal distribution and can lead to a kinship-based spatial structure, where proximity and relatedness are tightly linked. In the Barents Sea region, polar bears (Ursus maritimus) of the coastal ecotype remain year-round within the Svalbard archipelago. This coastal strategy is thought to be stable across years; however, little is known about the intra-individual variability in site fidelity or the influence of kinship on space use. Using high-resolution GPS telemetry, we looked at multi-year philopatry among 17 coastal female polar bears over eight years (2011–19) and investigated whether it is linked to the females’ degree of kinship. Individuals showed a stable space use in both consecutive and non-consecutive years. Yearly individual home ranges (HRs) overlapped, on average, by 44% (range: 9–96%), and their centroids were, on average, 15 km (range: 2–63 km) apart. The space use of related females revealed a year-round strong female kin structure. Annual HRs of related females overlapped, on average, by 24% (range: 0–66%), and their centroids were, on average, 18 km (range: 2–52 km) apart. In contrast, non-related females had much larger distances between centroids (average: 160 km, range: 59–283 km). Additionally, females showed a great site fidelity in all seasons: individual seasonal HR centroids were, on average, less than 30 km (range: 1.8–172 km) apart. Bears in this region seem to exhibit a stronger site fidelity than those reported from other parts of the species range. These findings also highlight the importance of maternal learning in space use.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49163390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Climate changes in the North Atlantic and Arctic affect the macrophytobenthos along with other components of the ecosystem, resulting in an increase of species diversity and biomass in western Spitsbergen, as has been reported. Grønfjorden is located at the mouth of one of the largest fjords of Spitsbergen, Isfjorden, and is influenced by the recent significant increase in the inflow of Atlantic Water. However, there are nearly no published data on the phytoben-thic communities in this area. This research study of the littoral and sublittoral areas of Grønfjorden in 2013–14 documented 68 species, mostly high-boreal and boreal–Arctic species. When compared with species diversity in the other areas of western Spitsbergen, the data show the uniqueness of Grønfjorden’s species composition.
{"title":"Species diversity of macroalgae in Grønfjorden, Spitsbergen, Svalbard","authors":"S. Malavenda","doi":"10.33265/POLAR.V40.3682","DOIUrl":"https://doi.org/10.33265/POLAR.V40.3682","url":null,"abstract":"Climate changes in the North Atlantic and Arctic affect the macrophytobenthos along with other components of the ecosystem, resulting in an increase of species diversity and biomass in western Spitsbergen, as has been reported. Grønfjorden is located at the mouth of one of the largest fjords of Spitsbergen, Isfjorden, and is influenced by the recent significant increase in the inflow of Atlantic Water. However, there are nearly no published data on the phytoben-thic communities in this area. This research study of the littoral and sublittoral areas of Grønfjorden in 2013–14 documented 68 species, mostly high-boreal and boreal–Arctic species. When compared with species diversity in the other areas of western Spitsbergen, the data show the uniqueness of Grønfjorden’s species composition.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47851331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intense, southward low-level winds are common in Nares Strait, between Ellesmere Island and northern Greenland. The steep topography along Nares Strait leads to channelling effects, resulting in an along-strait flow. This research study presents a 30-year climatology of the flow regime from simulations of the COSMO-CLM climate model. The simulations are available for the winter periods (November–April) 1987/88 to 2016/17, and thus, cover a period long enough to give robust long-term characteristics of Nares Strait. The horizontal resolution of 15 km is high enough to represent the complex terrain and the meteorological conditions realistically. The 30-year climatology shows that LLJs associated with gap flows are a climatological feature of Nares Strait. The maximum of the mean 10-m wind speed is around 12 m s-1 and is located at the southern exit of Smith Sound. The wind speed is strongly related to the pressure gradient. Single events reach wind speeds of 40 m s-1 in the daily mean. The LLJs are associated with gap flows within the narrowest parts of the strait under stably stratified conditions, with the main LLJ occurring at 100–250 m height. With increasing mountain Froude number, the LLJ wind speed and height increase. The frequency of strong wind events (>20 m s-1 in the daily mean) for the 10 m wind shows a strong interannual variability with an average of 15 events per winter. Channelled winds have a strong impact on the formation of the North Water polynya.
在埃尔斯米尔岛和格陵兰岛北部之间的纳尔斯海峡，强烈的低空南风很常见。纳尔斯海峡陡峭的地形导致了通道效应，导致了海峡沿岸的水流。本研究提出了COSMO-CLM气候模式模拟的30年流态气候学。模拟可用于1987/88年至2016/17年的冬季(11月至4月)，因此覆盖的时间足够长，可以提供纳雷斯海峡的长期特征。15 km的水平分辨率足以真实地反映复杂的地形和气象条件。30年气候学研究表明，与间隙流相关的llj是纳雷斯海峡的一个气候特征。10 m平均风速最大值约为12 m s-1，位于史密斯湾南出口。风速与压力梯度密切相关。单次事件的日平均风速可达40 m s-1。在稳定的分层条件下，LLJ与海峡最狭窄部分的间隙流动有关，主要LLJ发生在100-250 m高度。随着山弗鲁德数的增加，LLJ风速和高度增加。10米级大风事件的频率(日平均为20 m s-1)表现出强烈的年际变化，平均每年冬季为15次。通道风对北水冰湖的形成有很强的影响。
{"title":"A climatology of wintertime low-level jets in Nares Strait","authors":"Svenja H. E. Kohnemann, G. Heinemann","doi":"10.33265/POLAR.V40.3622","DOIUrl":"https://doi.org/10.33265/POLAR.V40.3622","url":null,"abstract":"Intense, southward low-level winds are common in Nares Strait, between Ellesmere Island and northern Greenland. The steep topography along Nares Strait leads to channelling effects, resulting in an along-strait flow. This research study presents a 30-year climatology of the flow regime from simulations of the COSMO-CLM climate model. The simulations are available for the winter periods (November–April) 1987/88 to 2016/17, and thus, cover a period long enough to give robust long-term characteristics of Nares Strait. The horizontal resolution of 15 km is high enough to represent the complex terrain and the meteorological conditions realistically. The 30-year climatology shows that LLJs associated with gap flows are a climatological feature of Nares Strait. The maximum of the mean 10-m wind speed is around 12 m s-1 and is located at the southern exit of Smith Sound. The wind speed is strongly related to the pressure gradient. Single events reach wind speeds of 40 m s-1 in the daily mean. The LLJs are associated with gap flows within the narrowest parts of the strait under stably stratified conditions, with the main LLJ occurring at 100–250 m height. With increasing mountain Froude number, the LLJ wind speed and height increase. The frequency of strong wind events (>20 m s-1 in the daily mean) for the 10 m wind shows a strong interannual variability with an average of 15 events per winter. Channelled winds have a strong impact on the formation of the North Water polynya.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44000090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study reports the disappearance of a small Arctic wolf population in north-east Greenland founded in 1979 and provides the first long-term information on the wolf packs of this region. Data sources comprised specialized wolf surveys in two of three distributional core areas during three summers, 2012–14, and incidental sightings of wolves by military ground patrols during winter and by others year-round. The resulting time series spans 40 years (1979–2018). After gradually increasing for 14 years, the sighting rate peaked in 1996 and then declined to zero after May 2002, suggesting that the population went extinct. The crash occurred despite year-round legal protection in a national park and resulted in a 51.2% reduction in the extent of the occupied wolf range in Greenland and a 41.8% reduction in Greenland’s wolf population size. It was outside the scope of this study to conduct a complete analysis of all potential factors in the disappearance. In north Greenland, a small population of up to 32 wolves during optimal years continues to exist, and dispersers reach north-east Greenland occasionally. A number of measures are proposed that, if implemented by the Greenland Home Rule Government, would help secure the future of the few remaining wolves on the island.
{"title":"Sudden death of an Arctic wolf population in Greenland","authors":"Ulf Marquard-Petersen","doi":"10.33265/POLAR.V40.5493","DOIUrl":"https://doi.org/10.33265/POLAR.V40.5493","url":null,"abstract":"This study reports the disappearance of a small Arctic wolf population in north-east Greenland founded in 1979 and provides the first long-term information on the wolf packs of this region. Data sources comprised specialized wolf surveys in two of three distributional core areas during three summers, 2012–14, and incidental sightings of wolves by military ground patrols during winter and by others year-round. The resulting time series spans 40 years (1979–2018). After gradually increasing for 14 years, the sighting rate peaked in 1996 and then declined to zero after May 2002, suggesting that the population went extinct. The crash occurred despite year-round legal protection in a national park and resulted in a 51.2% reduction in the extent of the occupied wolf range in Greenland and a 41.8% reduction in Greenland’s wolf population size. It was outside the scope of this study to conduct a complete analysis of all potential factors in the disappearance. In north Greenland, a small population of up to 32 wolves during optimal years continues to exist, and dispersers reach north-east Greenland occasionally. A number of measures are proposed that, if implemented by the Greenland Home Rule Government, would help secure the future of the few remaining wolves on the island.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49113400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The consequences of global change cannot be estimated without long-term monitoring programmes. The Kola Meridian transect, along 33°30’E, in the Barents Sea is the longest term monitoring area in the Arctic. Regular (usually annual) hydrobiological benthic surveys along that transect have been performed since 1899. Materials stored in museum collections remain the main source of the faunistic information obtained during the surveys, while only a minor part of these data was published. We reexamined all samples of shell-bearing gastropods from the Kola Meridian stored at the Zoological Institute of the Russian Academy of Sciences and at Saint Petersburg State University. We found only 159 museum lots from 73 samples, which constitute a very small portion of the total material collected along the transect. Approximately one-third of them (54 lots) was misidentified or includes individuals that cannot be identified at species level. The species composition revealed by museum materials differs substantially from published checklists. Majority of the studied samples (40) were collected during 1899–1920. However, the extant collections do not provide a reliable baseline for the Kola Meridian. We propose that the storage of zoological material in public collections should be considered as an essential part of long-term monitoring programmes.
{"title":"Missing and misidentified museum specimens hinder long-term monitoring: a case study of shell-bearing gastropods from the Kola Meridian transect, Barents Sea","authors":"I. Nekhaev, A. Merkuliev","doi":"10.33265/POLAR.V40.4999","DOIUrl":"https://doi.org/10.33265/POLAR.V40.4999","url":null,"abstract":"The consequences of global change cannot be estimated without long-term monitoring programmes. The Kola Meridian transect, along 33°30’E, in the Barents Sea is the longest term monitoring area in the Arctic. Regular (usually annual) hydrobiological benthic surveys along that transect have been performed since 1899. Materials stored in museum collections remain the main source of the faunistic information obtained during the surveys, while only a minor part of these data was published. We reexamined all samples of shell-bearing gastropods from the Kola Meridian stored at the Zoological Institute of the Russian Academy of Sciences and at Saint Petersburg State University. We found only 159 museum lots from 73 samples, which constitute a very small portion of the total material collected along the transect. Approximately one-third of them (54 lots) was misidentified or includes individuals that cannot be identified at species level. The species composition revealed by museum materials differs substantially from published checklists. Majority of the studied samples (40) were collected during 1899–1920. However, the extant collections do not provide a reliable baseline for the Kola Meridian. We propose that the storage of zoological material in public collections should be considered as an essential part of long-term monitoring programmes.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46583699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Skorupski, M. Szenejko, Martyna Gruba-Tabaka, P. Śmietana, R. Panicz
Polar and subpolar regions are known for their particular vulnerability and sensitivity to the detrimental effects of non-indigenous species, which is well exemplified by the Nootka lupin (Lupinus nootkatensis) spread in Iceland. Since understanding the population and ecological genetics of invasive alien species offers hope for counteracting harmful biological invasions, the objective of the present study was to investigate interspecific variation in L. nootkatensis in Iceland in relation to a native population in Alaska. Moreover, we aimed to assess whether internal transcribed spacer 2 (ITS2) has sufficient phylogenetic applicability for a large-scale screening of the genetic diversity of a non-indigenous population of this species. This study, which is the first attempt to investigate the genetic diversity of the Nootka lupin in Iceland, included plant samples from eight locations in Iceland and one in Alaska. The analyses included genotyping by sequencing of the 417-nucleotide fragment of the 5.8S ribosomal RNA, ITS2 and part of the large subunit ribosomal RNA (GenBank MT026578-MT026580, MT077004). The main findings showed the presence of five previously unexplained single-nucleotide polymorphisms (SNPs); however, their discriminatory power for Icelandic populations was relatively low, since polymorphism information content (PIC) values ranged from 0.0182 to 0.0526, with average heterozygosity 0.0296. Concomitantly, analysis of multilocus genotypes (MLG) revealed sufficient differences in MLGs variants and their frequency to form genotypic patterns unique for Alaskan and Icelandic populations, revealing an internal genetic structure of the studied group. The proposed SNP panel needs to be supplemented with other nuclear and organellar markers.
{"title":"Inferring population structure and genetic diversity of the invasive alien Nootka lupin in Iceland","authors":"J. Skorupski, M. Szenejko, Martyna Gruba-Tabaka, P. Śmietana, R. Panicz","doi":"10.33265/POLAR.V40.4536","DOIUrl":"https://doi.org/10.33265/POLAR.V40.4536","url":null,"abstract":"Polar and subpolar regions are known for their particular vulnerability and sensitivity to the detrimental effects of non-indigenous species, which is well exemplified by the Nootka lupin (Lupinus nootkatensis) spread in Iceland. Since understanding the population and ecological genetics of invasive alien species offers hope for counteracting harmful biological invasions, the objective of the present study was to investigate interspecific variation in L. nootkatensis in Iceland in relation to a native population in Alaska. Moreover, we aimed to assess whether internal transcribed spacer 2 (ITS2) has sufficient phylogenetic applicability for a large-scale screening of the genetic diversity of a non-indigenous population of this species. This study, which is the first attempt to investigate the genetic diversity of the Nootka lupin in Iceland, included plant samples from eight locations in Iceland and one in Alaska. The analyses included genotyping by sequencing of the 417-nucleotide fragment of the 5.8S ribosomal RNA, ITS2 and part of the large subunit ribosomal RNA (GenBank MT026578-MT026580, MT077004). The main findings showed the presence of five previously unexplained single-nucleotide polymorphisms (SNPs); however, their discriminatory power for Icelandic populations was relatively low, since polymorphism information content (PIC) values ranged from 0.0182 to 0.0526, with average heterozygosity 0.0296. Concomitantly, analysis of multilocus genotypes (MLG) revealed sufficient differences in MLGs variants and their frequency to form genotypic patterns unique for Alaskan and Icelandic populations, revealing an internal genetic structure of the studied group. The proposed SNP panel needs to be supplemented with other nuclear and organellar markers.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":"40 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45721705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Bengtsson, Charmain D. Hamilton, C. Lydersen, Magnus Andersen, K. Kovacs
This study presents comprehensive mapping of the current distribution of pinnipeds and polar bears (Ursus maritimus) around Svalbard based on a regional marine mammal sightings programme and explores time-trends (2005–2018). Walruses (Odobenus rosmarus) were observed with high frequency and in high numbers around previously identified haul-out sites. At-sea walruses were seen close to the coast in shallow waters. Ringed seals (Pusa hispida) were observed in coastal areas throughout Svalbard, often in association with tidewater glacier fronts. There was no increase in the mean latitude for ringed seal observations, but there was an increased frequency of observations at around 82°N, which reflects their following a northward shift in the ice edge during summer foraging trips. Bearded seals (Erignathus barbatus) were observed frequently in north-western Spitsbergen and shared many habitat features with ringed seals. There was a slight increase in the mean latitude of bearded seal observations and a decreased frequency of observation in the southern parts of the archipelago, suggesting that this species might be shifting its distribution. Harbour seal (Phoca vitulina) observations within fjords have increased, likely as a consequence of increased inflow of Atlantic water into west coast fjords. Harp seals (Pagophilus groenlandicus) were observed with high frequency north of Svalbard. Hooded seals (Cystophora cristata) were observed only rarely. Polar bears were reported most frequently, undoubtedly as a result of an effort bias favouring this species. In spite of biases, citizen-based observations are useful for assessing broad distributional patterns of marine mammals through time.
{"title":"Distribution and habitat characteristics of pinnipeds and polar bears in the Svalbard Archipelago, 2005–2018","authors":"O. Bengtsson, Charmain D. Hamilton, C. Lydersen, Magnus Andersen, K. Kovacs","doi":"10.33265/POLAR.V40.5326","DOIUrl":"https://doi.org/10.33265/POLAR.V40.5326","url":null,"abstract":"This study presents comprehensive mapping of the current distribution of pinnipeds and polar bears (Ursus maritimus) around Svalbard based on a regional marine mammal sightings programme and explores time-trends (2005–2018). Walruses (Odobenus rosmarus) were observed with high frequency and in high numbers around previously identified haul-out sites. At-sea walruses were seen close to the coast in shallow waters. Ringed seals (Pusa hispida) were observed in coastal areas throughout Svalbard, often in association with tidewater glacier fronts. There was no increase in the mean latitude for ringed seal observations, but there was an increased frequency of observations at around 82°N, which reflects their following a northward shift in the ice edge during summer foraging trips. Bearded seals (Erignathus barbatus) were observed frequently in north-western Spitsbergen and shared many habitat features with ringed seals. There was a slight increase in the mean latitude of bearded seal observations and a decreased frequency of observation in the southern parts of the archipelago, suggesting that this species might be shifting its distribution. Harbour seal (Phoca vitulina) observations within fjords have increased, likely as a consequence of increased inflow of Atlantic water into west coast fjords. Harp seals (Pagophilus groenlandicus) were observed with high frequency north of Svalbard. Hooded seals (Cystophora cristata) were observed only rarely. Polar bears were reported most frequently, undoubtedly as a result of an effort bias favouring this species. In spite of biases, citizen-based observations are useful for assessing broad distributional patterns of marine mammals through time.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49408311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Li, Hongling Shi, Yang Lu, Zizhan Zhang, Hui Xi
In this paper, we examine potential impact of discharge in Subglacial Lake Engelhardt, West Antarctica, on the stability of the Ross Ice Shelf around the grounding line by combining satellite altimetry and remote sensing images. According to satellite altimetry data from the Ice, Cloud and Land Elevation Satellite (ICESat; 2003–06), Subglacial Lake Engelhardt (SLE) discharged ca. 1.91 ± 0.04 km3 of water into the downstream region. The ice-surface record derived from ICESat (2006–09) and CryoSat-2 (2011–17) data shows that the lake gained ca. 2.09 ± 0.05 km3 of water during the refilling event following the drainage event, taking three times as much time to reach the previous water level before the discharge; the calculation demonstrates that water input from an upstream lake is unable to sustain water increase in SLE, indicating that the subglacial, hydrologic system and groundwater flow could have contributed to water increase in SLE via hydrologic networks. Satellite images captured surface depressions and crevasses at the drainage outlet point of hydrologic networks around the grounding line; satellite altimetry data show that the ice surface there is still depressing even though the subglacial discharge has finished, potentially reflecting the long-term impact of subglacial discharge on the stability of the immediate Ross Ice Shelf around the grounding line.
{"title":"Subglacial discharge weakens the stability of the Ross Ice Shelf around the grounding line","authors":"Yan Li, Hongling Shi, Yang Lu, Zizhan Zhang, Hui Xi","doi":"10.33265/POLAR.V40.3377","DOIUrl":"https://doi.org/10.33265/POLAR.V40.3377","url":null,"abstract":"In this paper, we examine potential impact of discharge in Subglacial Lake Engelhardt, West Antarctica, on the stability of the Ross Ice Shelf around the grounding line by combining satellite altimetry and remote sensing images. According to satellite altimetry data from the Ice, Cloud and Land Elevation Satellite (ICESat; 2003–06), Subglacial Lake Engelhardt (SLE) discharged ca. 1.91 ± 0.04 km3 of water into the downstream region. The ice-surface record derived from ICESat (2006–09) and CryoSat-2 (2011–17) data shows that the lake gained ca. 2.09 ± 0.05 km3 of water during the refilling event following the drainage event, taking three times as much time to reach the previous water level before the discharge; the calculation demonstrates that water input from an upstream lake is unable to sustain water increase in SLE, indicating that the subglacial, hydrologic system and groundwater flow could have contributed to water increase in SLE via hydrologic networks. Satellite images captured surface depressions and crevasses at the drainage outlet point of hydrologic networks around the grounding line; satellite altimetry data show that the ice surface there is still depressing even though the subglacial discharge has finished, potentially reflecting the long-term impact of subglacial discharge on the stability of the immediate Ross Ice Shelf around the grounding line.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48299387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Permafrost soils differ significantly from other soils because they serve as a huge reservoir for organic carbon accumulated during the Quaternary Period, which is at risk of being released as the Arctic warms. This study aimed to characterize existing carbon pools, delineate possible mineralization risks of soil organic matter and assess microbial communities in the tundra and forest–tundra permafrost soils of the southern Yamal region of Russia. The profile distribution of carbon, nitrogen and the C:N ratio showed non-gradual changes with depth due to the manifestation of cryopedogenesis in soil profiles, which lead to cryogenic mass transfer. Mean carbon stocks for the study area were 7.85 ± 2.24 kg m−2 (0–10 cm layer), 14.97 ± 5.53 kg m−2 (0–30 cm) and 23.99 ± 8.00 kg m−2 (0–100 cm). The analysis of the humus type revealed a predominance of fulvic type and low-molecular-weight fragments in the fulvic acid fraction, which indicates high mineralization risk of humic substances under Arctic warming conditions. The taxonomic analysis of soil microbiomes revealed 48 bacterial and archaeal phyla, among which proteobacteria (27%) and actinobacteria (20%) were predominant. The pH range and nitrogen accumulation were the main environmental determinants of microbial community diversity and composition in the studied soils.
永久冻土与其他土壤有很大不同，因为它们是第四纪期间积累的有机碳的巨大储存库，随着北极变暖，这些有机碳有被释放的危险。本研究旨在描述俄罗斯南部亚马尔地区冻土带和森林冻土带永久冻土土壤中现有碳库的特征，描绘土壤有机质可能的矿化风险，并评估微生物群落。由于土壤剖面中低温发生的表现，碳、氮和C:N的剖面分布随深度呈非渐进式变化，导致低温传质。研究区平均碳储量分别为7.85±2.24 kg m−2 (0 ~ 10 cm)、14.97±5.53 kg m−2 (0 ~ 30 cm)和23.99±8.00 kg m−2 (0 ~ 100 cm)。腐殖质类型分析显示，腐殖质组分以黄腐酸型和低分子量片段为主，表明北极变暖条件下腐殖质具有较高的矿化风险。土壤微生物组的分类分析显示48个细菌和古细菌门，其中以变形菌门(27%)和放线菌门(20%)为主。pH范围和氮积累是影响土壤微生物群落多样性和组成的主要环境因素。
{"title":"Organic carbon and microbiome in tundra and forest–tundra permafrost soils, southern Yamal, Russia","authors":"I. Alekseev, A. Zverev, E. Abakumov","doi":"10.33265/POLAR.V40.5283","DOIUrl":"https://doi.org/10.33265/POLAR.V40.5283","url":null,"abstract":"Permafrost soils differ significantly from other soils because they serve as a huge reservoir for organic carbon accumulated during the Quaternary Period, which is at risk of being released as the Arctic warms. This study aimed to characterize existing carbon pools, delineate possible mineralization risks of soil organic matter and assess microbial communities in the tundra and forest–tundra permafrost soils of the southern Yamal region of Russia. The profile distribution of carbon, nitrogen and the C:N ratio showed non-gradual changes with depth due to the manifestation of cryopedogenesis in soil profiles, which lead to cryogenic mass transfer. Mean carbon stocks for the study area were 7.85 ± 2.24 kg m−2 (0–10 cm layer), 14.97 ± 5.53 kg m−2 (0–30 cm) and 23.99 ± 8.00 kg m−2 (0–100 cm). The analysis of the humus type revealed a predominance of fulvic type and low-molecular-weight fragments in the fulvic acid fraction, which indicates high mineralization risk of humic substances under Arctic warming conditions. The taxonomic analysis of soil microbiomes revealed 48 bacterial and archaeal phyla, among which proteobacteria (27%) and actinobacteria (20%) were predominant. The pH range and nitrogen accumulation were the main environmental determinants of microbial community diversity and composition in the studied soils.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48530813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flaviana Jorge de Lima, Juliana Manso Sayão, L. C. M. O. Ponciano, L. Weinschütz, Rodrigo G. Figueiredo, Taissa Rodrigues, Renan Alfredo Machado Bantim, Antonio Álamo Feitosa Saraiva, A. Jasper, D. Uhl, A. Kellner
The Cretaceous “high-fire” period was a global event that reached almost all continental masses during that period in Earth’s history. The extensive wildfires directly affected plant communities. Significant palaeobotanical records in the Antarctic Peninsula have been studied from the James Ross Sub-Basin, especially from the Santa Marta Formation. However, there is no described evidence for palaeo-wildfires in the area so far. Here, we present the first occurrence of fossilized macro-charcoal coming from James Ross Island, confirming that palaeo-wildfires occurred in the Campanian vegetation preserved in the Santa Marta Formation. The new charcoal material has a gymnospermous taxonomic affinity, more specifically with the Araucariaceae, which is in accordance with previous palaeobotanical records from James Ross Island. This occurrence adds new information to the construction of the palaeo-wildfire scenario for Gondwana.
{"title":"Wildfires in the Campanian of James Ross Island: a new macro-charcoal record for the Antarctic Peninsula","authors":"Flaviana Jorge de Lima, Juliana Manso Sayão, L. C. M. O. Ponciano, L. Weinschütz, Rodrigo G. Figueiredo, Taissa Rodrigues, Renan Alfredo Machado Bantim, Antonio Álamo Feitosa Saraiva, A. Jasper, D. Uhl, A. Kellner","doi":"10.33265/polar.v40.5487","DOIUrl":"https://doi.org/10.33265/polar.v40.5487","url":null,"abstract":"The Cretaceous “high-fire” period was a global event that reached almost all continental masses during that period in Earth’s history. The extensive wildfires directly affected plant communities. Significant palaeobotanical records in the Antarctic Peninsula have been studied from the James Ross Sub-Basin, especially from the Santa Marta Formation. However, there is no described evidence for palaeo-wildfires in the area so far. Here, we present the first occurrence of fossilized macro-charcoal coming from James Ross Island, confirming that palaeo-wildfires occurred in the Campanian vegetation preserved in the Santa Marta Formation. The new charcoal material has a gymnospermous taxonomic affinity, more specifically with the Araucariaceae, which is in accordance with previous palaeobotanical records from James Ross Island. This occurrence adds new information to the construction of the palaeo-wildfire scenario for Gondwana.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":"1 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69593763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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