B. E. Grøsvik, L. Buhl‐Mortensen, M. Bergmann, A. Booth, A. Gomiero, F. Galgani
Marine litter in the Arctic Basin is influenced by transport from Atlantic and Pacific waters. This highlights the need for harmonization of guidelines across regions. Monitoring can be used to assess temporal and spatial trends but can also be used to assess if environmental objectives are reached, for example to evaluate the effectiveness of mitigation measures. Seafloor monitoring by trawling needs substantial resources and specific sampling strategies to be sufficiently robust to demonstrate changes over time. Observation and visual evaluation in shallow and deep waters using towed camera systems, ROVs and submersibles are well suited for the Arctic environment. The use of imagery still needs to be adjusted through automation and image analyses, including deep learning approaches and data management, but will also serve to monitor areas with a rocky seafloor. We recommend developing a monitoring plan for seafloor litter by selecting representative sites for visual inspection that cover different depths and substrata in marine landscapes, and recording the litter collected or observed across all forms of seafloor sampling or imaging. We need better coverage and knowledge of status of seafloor litter for the whole Arctic and recommend initiatives to be taken for regions where such knowledge is lacking.
{"title":"Status and future recommendations for recording and monitoring litter on the Arctic seafloor","authors":"B. E. Grøsvik, L. Buhl‐Mortensen, M. Bergmann, A. Booth, A. Gomiero, F. Galgani","doi":"10.1139/as-2022-0017","DOIUrl":"https://doi.org/10.1139/as-2022-0017","url":null,"abstract":"Marine litter in the Arctic Basin is influenced by transport from Atlantic and Pacific waters. This highlights the need for harmonization of guidelines across regions. Monitoring can be used to assess temporal and spatial trends but can also be used to assess if environmental objectives are reached, for example to evaluate the effectiveness of mitigation measures. Seafloor monitoring by trawling needs substantial resources and specific sampling strategies to be sufficiently robust to demonstrate changes over time. Observation and visual evaluation in shallow and deep waters using towed camera systems, ROVs and submersibles are well suited for the Arctic environment. The use of imagery still needs to be adjusted through automation and image analyses, including deep learning approaches and data management, but will also serve to monitor areas with a rocky seafloor. We recommend developing a monitoring plan for seafloor litter by selecting representative sites for visual inspection that cover different depths and substrata in marine landscapes, and recording the litter collected or observed across all forms of seafloor sampling or imaging. We need better coverage and knowledge of status of seafloor litter for the whole Arctic and recommend initiatives to be taken for regions where such knowledge is lacking.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42783088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Excess ice, found as massive ice and within icy sediments, is an important variable to quantify as it is a dominant control on the terrain and geotechnical response to permafrost thaw. A large amount of permafrost borehole data are available from the Tuktoyaktuk Coastlands, however, field geotechnical assessments typically only involve the estimation of visible ice. To add significant value to these datasets, a cryostratigraphic dataset collected along the Inuvik-Tuktoyaktuk Highway (566 boreholes) is used to develop a beta regression model which predicts the excess ice content of icy sediments based on interval depth, visible ice content, material type, and Quaternary deposits. The resulting predictions are compared to recorded massive ice intervals and show that ground ice within icy sediments can contribute up to 65% of the excess ice and potential thaw strain within the first 10 meters from the surface in this area. This study shows the general applicability of this approach and indicates that comparable, quantitative data on ground ice conditions should be collected with drilling programs to derive geotechnical variables and reduce modeling uncertainties so that ground ice data are available for quantitative analysis.
{"title":"Vertical distribution of excess ice in icy sediments and its statistical estimation from geotechnical data (Tuktoyaktuk Coastlands and Anderson Plain, Northwest Territories)","authors":"A. Castagner, A. Brenning, S. Gruber, S. Kokelj","doi":"10.1139/as-2021-0041","DOIUrl":"https://doi.org/10.1139/as-2021-0041","url":null,"abstract":"Excess ice, found as massive ice and within icy sediments, is an important variable to quantify as it is a dominant control on the terrain and geotechnical response to permafrost thaw. A large amount of permafrost borehole data are available from the Tuktoyaktuk Coastlands, however, field geotechnical assessments typically only involve the estimation of visible ice. To add significant value to these datasets, a cryostratigraphic dataset collected along the Inuvik-Tuktoyaktuk Highway (566 boreholes) is used to develop a beta regression model which predicts the excess ice content of icy sediments based on interval depth, visible ice content, material type, and Quaternary deposits. The resulting predictions are compared to recorded massive ice intervals and show that ground ice within icy sediments can contribute up to 65% of the excess ice and potential thaw strain within the first 10 meters from the surface in this area. This study shows the general applicability of this approach and indicates that comparable, quantitative data on ground ice conditions should be collected with drilling programs to derive geotechnical variables and reduce modeling uncertainties so that ground ice data are available for quantitative analysis.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46302941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Saros, C. Arp, F. Bouchard, J. Comte, R. Couture, J. Dean, M. Lafrenière, S. Macintyre, S. McGowan, M. Rautio, C. Prater, S. Tank, M. Walvoord, K. Wickland, D. Antoniades, Paola Ayala-Borda, J. Canário, T. Drake, Diogo Folhas, V. Hazuková, Henriikka E. Kivilä, Y. Klanten, S. Lamoureux, I. Laurion, Rachel M. Pilla, J. Vonk, S. Zolkos, W. Vincent
While the sentinel nature of freshwater systems is now well-recognized, widespread integration of freshwater processes and patterns into our understanding of broader climate-driven Arctic terrestrial ecosystem change has been slow. We review the current understanding across Arctic freshwater systems of key sentinel responses to climate, which are attributes of these systems with demonstrated and sensitive responses to climate forcing. These include ice regimes, temperature and thermal structure, river baseflow, lake area and water level, permafrost-derived dissolved ions and nutrients, carbon mobilization (dissolved organic carbon, greenhouse gases, and radiocarbon), dissolved oxygen concentrations, lake trophic state, various aquatic organisms and their traits, and invasive species. For each sentinel, our objectives are to clarify linkages to climate, describe key insights already gained, and provide suggestions for future research based on current knowledge gaps. We suggest that tracking key responses in Arctic freshwater systems will expand understanding of the breadth and depth of climate-driven Arctic ecosystem changes, provide early indicators of looming, broader changes across the landscape, and improve protection of freshwater biodiversity and resources.
{"title":"Sentinel responses of Arctic freshwater systems to climate: linkages, evidence, and a roadmap for future research","authors":"J. Saros, C. Arp, F. Bouchard, J. Comte, R. Couture, J. Dean, M. Lafrenière, S. Macintyre, S. McGowan, M. Rautio, C. Prater, S. Tank, M. Walvoord, K. Wickland, D. Antoniades, Paola Ayala-Borda, J. Canário, T. Drake, Diogo Folhas, V. Hazuková, Henriikka E. Kivilä, Y. Klanten, S. Lamoureux, I. Laurion, Rachel M. Pilla, J. Vonk, S. Zolkos, W. Vincent","doi":"10.1139/as-2022-0021","DOIUrl":"https://doi.org/10.1139/as-2022-0021","url":null,"abstract":"While the sentinel nature of freshwater systems is now well-recognized, widespread integration of freshwater processes and patterns into our understanding of broader climate-driven Arctic terrestrial ecosystem change has been slow. We review the current understanding across Arctic freshwater systems of key sentinel responses to climate, which are attributes of these systems with demonstrated and sensitive responses to climate forcing. These include ice regimes, temperature and thermal structure, river baseflow, lake area and water level, permafrost-derived dissolved ions and nutrients, carbon mobilization (dissolved organic carbon, greenhouse gases, and radiocarbon), dissolved oxygen concentrations, lake trophic state, various aquatic organisms and their traits, and invasive species. For each sentinel, our objectives are to clarify linkages to climate, describe key insights already gained, and provide suggestions for future research based on current knowledge gaps. We suggest that tracking key responses in Arctic freshwater systems will expand understanding of the breadth and depth of climate-driven Arctic ecosystem changes, provide early indicators of looming, broader changes across the landscape, and improve protection of freshwater biodiversity and resources.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41511526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The spatial distributions of several small mammals in Nunavik, Québec, Canada, currently do not rely on any recorded observations due to the rarity of wildlife surveys in that area. This is concerning because understanding changes in wildlife populations in response to the rapidly warming Arctic requires knowledge of prior population states. On the 18th of July 2021, my assistant and I captured a least weasel (Mustela nivalis Linnaeus 1766) alive 11 km south-west of Salluit during a live trapping session of lemmings and voles. Identification was done with the small body mass (44 g), the presence of prominent testicles indicating maturity, short length of the tail and pale color at the tip of the tail. All these criteria combined fits only the description of least weasels. According to the available records for this species, this observation is the first one confirmed in Nunavik. This low Arctic area was already included in the species distribution described in the literature, but no record supported it up to now. It is of particular importance considering this species is susceptible to be designated as threatened or vulnerable in the province of Quebec according to the Centre de données sur le patrimoine naturel du Québec.
{"title":"First record of a least weasel in Nunavik","authors":"D. Fauteux","doi":"10.1139/as-2022-0029","DOIUrl":"https://doi.org/10.1139/as-2022-0029","url":null,"abstract":"The spatial distributions of several small mammals in Nunavik, Québec, Canada, currently do not rely on any recorded observations due to the rarity of wildlife surveys in that area. This is concerning because understanding changes in wildlife populations in response to the rapidly warming Arctic requires knowledge of prior population states. On the 18th of July 2021, my assistant and I captured a least weasel (Mustela nivalis Linnaeus 1766) alive 11 km south-west of Salluit during a live trapping session of lemmings and voles. Identification was done with the small body mass (44 g), the presence of prominent testicles indicating maturity, short length of the tail and pale color at the tip of the tail. All these criteria combined fits only the description of least weasels. According to the available records for this species, this observation is the first one confirmed in Nunavik. This low Arctic area was already included in the species distribution described in the literature, but no record supported it up to now. It is of particular importance considering this species is susceptible to be designated as threatened or vulnerable in the province of Quebec according to the Centre de données sur le patrimoine naturel du Québec.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46003468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Hollister, Cassandra Elphinstone, G. Henry, Anne D. Bjorkman, K. Klanderud, R. Björk, Mats P. Björkman, S. Bokhorst, M. Carbognani, E. Cooper, E. Dorrepaal, S. Elmendorf, N. Fetcher, Elise C. Gallois, J. Gudmundsson, N. Healey, I. Jónsdóttir, I. Klarenberg, S. Oberbauer, P. Macek, J. May, Alessandro Mereghetti, U. Molau, A. Petraglia, R. Rinnan, C. Rixen, P. Wookey
Open top chambers (OTCs) were adopted as the recommended warming mechanism by the International Tundra Experiment (ITEX) network in the early 1990’s. Since then, OTCs have been deployed across the globe. Hundreds of papers have reported the impacts of OTCs on the abiotic environment and the biota. Here we review the impacts of the OTC on the physical environment, with comments on the appropriateness of using OTCs to characterize the response of biota to warming. The purpose of this review is to guide readers to previously published work and to provide recommendations for continued use of OTCs to understand the implications of warming on low stature ecosystems. In short, the OTC is a useful tool to experimentally manipulate temperature, however the characteristics and magnitude of warming varies greatly in different environments, therefore it is important to document chamber performance to maximize the interpretation of biotic response. When coupled with long-term monitoring, warming experiments are a valuable means to understand the impacts of climate change on natural ecosystems.
{"title":"A review of open top chamber (OTC) performance across the ITEX Network","authors":"R. Hollister, Cassandra Elphinstone, G. Henry, Anne D. Bjorkman, K. Klanderud, R. Björk, Mats P. Björkman, S. Bokhorst, M. Carbognani, E. Cooper, E. Dorrepaal, S. Elmendorf, N. Fetcher, Elise C. Gallois, J. Gudmundsson, N. Healey, I. Jónsdóttir, I. Klarenberg, S. Oberbauer, P. Macek, J. May, Alessandro Mereghetti, U. Molau, A. Petraglia, R. Rinnan, C. Rixen, P. Wookey","doi":"10.1139/as-2022-0030","DOIUrl":"https://doi.org/10.1139/as-2022-0030","url":null,"abstract":"Open top chambers (OTCs) were adopted as the recommended warming mechanism by the International Tundra Experiment (ITEX) network in the early 1990’s. Since then, OTCs have been deployed across the globe. Hundreds of papers have reported the impacts of OTCs on the abiotic environment and the biota. Here we review the impacts of the OTC on the physical environment, with comments on the appropriateness of using OTCs to characterize the response of biota to warming. The purpose of this review is to guide readers to previously published work and to provide recommendations for continued use of OTCs to understand the implications of warming on low stature ecosystems. In short, the OTC is a useful tool to experimentally manipulate temperature, however the characteristics and magnitude of warming varies greatly in different environments, therefore it is important to document chamber performance to maximize the interpretation of biotic response. When coupled with long-term monitoring, warming experiments are a valuable means to understand the impacts of climate change on natural ecosystems.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47461439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arctic permafrost is degrading and is thus releasing nutrients, solutes, sediment and water into soils and freshwater ecosystems. The impacts of this degradation depends on the geochemical characteristics and in large part on the spatial distribution of ground ice and solutes, which is not well-known in the High Arctic polar desert ecosystems. This research links ground ice and solute concentrations, to establish a framework for identifying locations vulnerable to permafrost degradation. It builds on landscape classifications and cryostratigraphic interpretations of permafrost history. Well-vegetated wetland sites with syngenetic permafrost aggradation show a different geochemical signature from polar desert and epigenetic sites. In wetlands, where ground ice contents were high (< 97% volume), total dissolved solute concentrations were relatively low (mean 283.0 ± 327.8 ppm), reflecting a carbonate terrestrial / freshwater setting. In drier sites with epigenetic origin, such as polar deserts, ice contents are low (< 47 % volume), solute concentrations were high (mean 3248.5 ± 1907.0 ppm, max 12055 ppm) and dominated by Na+ and Cl- ions, reflecting a post-glacial marine inundation during permafrost formation. Dissolved organic carbon and total dissolved nitrogen concentrations usually increased at the top of permafrost and could not be as clearly associated with permafrost history. The research shows that the geochemistry of polar desert permafrost is highly dependent on permafrost history, and it can be estimated using hydrogeomorphological terrain classifications.
{"title":"Landscape influence on permafrost ground ice geochemistry in a polar desert environment, Resolute Bay, Nunavut","authors":"Michel Paquette, M. Lafrenière, S. Lamoureux","doi":"10.1139/as-2021-0049","DOIUrl":"https://doi.org/10.1139/as-2021-0049","url":null,"abstract":"Arctic permafrost is degrading and is thus releasing nutrients, solutes, sediment and water into soils and freshwater ecosystems. The impacts of this degradation depends on the geochemical characteristics and in large part on the spatial distribution of ground ice and solutes, which is not well-known in the High Arctic polar desert ecosystems. This research links ground ice and solute concentrations, to establish a framework for identifying locations vulnerable to permafrost degradation. It builds on landscape classifications and cryostratigraphic interpretations of permafrost history. Well-vegetated wetland sites with syngenetic permafrost aggradation show a different geochemical signature from polar desert and epigenetic sites. In wetlands, where ground ice contents were high (< 97% volume), total dissolved solute concentrations were relatively low (mean 283.0 ± 327.8 ppm), reflecting a carbonate terrestrial / freshwater setting. In drier sites with epigenetic origin, such as polar deserts, ice contents are low (< 47 % volume), solute concentrations were high (mean 3248.5 ± 1907.0 ppm, max 12055 ppm) and dominated by Na+ and Cl- ions, reflecting a post-glacial marine inundation during permafrost formation. Dissolved organic carbon and total dissolved nitrogen concentrations usually increased at the top of permafrost and could not be as clearly associated with permafrost history. The research shows that the geochemistry of polar desert permafrost is highly dependent on permafrost history, and it can be estimated using hydrogeomorphological terrain classifications.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43583047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Pouliot, Mao Mao, R. Fraser, Blair E. Kennedy, S. Leblanc, Liming He, Wenjun Chen
Effective plot-based field sampling involves a trade-off between implementation efficiency and sample error. Optimal field sampling therefore requires quantifying the sample error under various sampling designs. For remote sensing applications, it is also important to understand how field sample error and training sample size (the number of pixels) affect the retrieval of surface properties. In this research, drone imagery was used to simulate field plots and investigate plot sampling error for forage lichen cover in relation to plot size, number of plots, and sampling strategy. The effect of this error on remote sensing-based lichen cover retrieval was evaluated using varying training sampling sizes in two different study regions in northern Canada. Results showed that cover with high spatial variability increased the number of plots or plot size required to achieve a specified level of error. For lichen cover retrieval at moderate spatial resolution (10–30 m), field sampling (plot size and number of plots) did not have as significant of an effect as regional differences (spectral separability of cover types), sensor, and the number of pixels used for model training. This plot simulation approach using drone images can be applied to other surface properties and regions to provide field sampling guidance.
{"title":"Using drone mapping to evaluate error of plot-based field surveys and its effects on moderate spatial resolution remote sensing retrieval of lichen cover","authors":"D. Pouliot, Mao Mao, R. Fraser, Blair E. Kennedy, S. Leblanc, Liming He, Wenjun Chen","doi":"10.1139/as-2021-0061","DOIUrl":"https://doi.org/10.1139/as-2021-0061","url":null,"abstract":"Effective plot-based field sampling involves a trade-off between implementation efficiency and sample error. Optimal field sampling therefore requires quantifying the sample error under various sampling designs. For remote sensing applications, it is also important to understand how field sample error and training sample size (the number of pixels) affect the retrieval of surface properties. In this research, drone imagery was used to simulate field plots and investigate plot sampling error for forage lichen cover in relation to plot size, number of plots, and sampling strategy. The effect of this error on remote sensing-based lichen cover retrieval was evaluated using varying training sampling sizes in two different study regions in northern Canada. Results showed that cover with high spatial variability increased the number of plots or plot size required to achieve a specified level of error. For lichen cover retrieval at moderate spatial resolution (10–30 m), field sampling (plot size and number of plots) did not have as significant of an effect as regional differences (spectral separability of cover types), sensor, and the number of pixels used for model training. This plot simulation approach using drone images can be applied to other surface properties and regions to provide field sampling guidance.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41750088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite a long-term thinning trend in freshwater ice in northern Alaska, cold low-snow cover winters can still emerge to grow thick ice. In 2021, we observed abnormally thick ice by winter’s end on lakes and rivers throughout the Fish Creek Watershed in the National Petroleum Reserve in Alaska (NPR-A). This recent and anomalous winter presented an opportunity to assess how such conditions, more typical of many decades’ previous, affected aquatic habitat and winter water supply. Observed maximum ice thickness in 2021 of 1.9 m closely matched low-snow ice-growth simulations, whereas previous records averaged 1.5 m and more closely matched high-snow ice-growth simulations. The resulting extent of bedfast lake ice from late winter synthetic aperture radar (SAR) analysis in 2021 was the highest on record since 1992. This SAR analysis suggests a 33% reduction in liquid water below ice by lake surface area compared to the recent thin-ice winter of 2018 (1.2 m). Together these results help place the cold, low-snow winter of 2020-21 in context of the long-term trend toward warmer, snowier winters that appear to becoming more common in arctic Alaska.
{"title":"Unusually Thick Freshwater Ice and its Impacts on Aquatic Resources in the National Petroleum Reserve in Alaska (NPR-A) during the Winter of 2020-21","authors":"C. Arp, M. Engram, A. Bondurant, Katie A. Drew","doi":"10.1139/as-2022-0027","DOIUrl":"https://doi.org/10.1139/as-2022-0027","url":null,"abstract":"Despite a long-term thinning trend in freshwater ice in northern Alaska, cold low-snow cover winters can still emerge to grow thick ice. In 2021, we observed abnormally thick ice by winter’s end on lakes and rivers throughout the Fish Creek Watershed in the National Petroleum Reserve in Alaska (NPR-A). This recent and anomalous winter presented an opportunity to assess how such conditions, more typical of many decades’ previous, affected aquatic habitat and winter water supply. Observed maximum ice thickness in 2021 of 1.9 m closely matched low-snow ice-growth simulations, whereas previous records averaged 1.5 m and more closely matched high-snow ice-growth simulations. The resulting extent of bedfast lake ice from late winter synthetic aperture radar (SAR) analysis in 2021 was the highest on record since 1992. This SAR analysis suggests a 33% reduction in liquid water below ice by lake surface area compared to the recent thin-ice winter of 2018 (1.2 m). Together these results help place the cold, low-snow winter of 2020-21 in context of the long-term trend toward warmer, snowier winters that appear to becoming more common in arctic Alaska.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46696546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the genetic diversity in natural plant populations is important in order to develop conservation strategies and utilize valuable germplasm resources. Chrysanthemum arcticum L., Arctic daisy, (=Arctanthemum arcticum; =Dendranthema arcticum) and its two subspecies (C. arcticum L. subsp. arcticum, C. arcticum L. subsp. polaré Hultén) are the only chrysanthemum species native to North America. We collected 529 individuals in nine C. arcticum and 21 C. a. subsp. arcticum populations from the state of Alaska mainland and Attu Island (the westernmost Aleutian Island). Evidence of declining population sizes and decreasing ranges of distribution were detected for both species and subspecies. Population genetic diversity was analyzed using 7,449 SNP markers developed using low density DArTseq technology. Three distinct genetic clusters within C. arcticum populations were detected by STRUCTURE 2.3.4, principal coordinate analysis (PCoA), discriminant analysis of principal components (DAPC), unweighted pair group method with arithmetic mean (UPGMA) and SplitsTree. SNP data showed a clear taxonomic distinction among C. arcticum and C. a. subsp. arcticum. However, within C. a. subsp. arcticum populations, two subgroups occurred in the genetic cluster analyses that were a mixture of individuals from different populations, which may be the result of gene flow.
了解自然植物群体的遗传多样性对制定保护策略和利用宝贵的种质资源具有重要意义。菊花(Chrysanthemum arcticum L.)，北极雏菊;北极菊)及其两个亚种(北极菊L. subsp.;arcticum, C. arcticum L. subsp。极乐菊(hultsamn)是唯一一种原产于北美的菊花。共收集到9个冰杉种和21个冰杉亚种529个个体。阿拉斯加大陆和阿图岛(阿留申群岛最西端)的北极冰种群。物种和亚种的种群规模和分布范围均呈下降趋势。利用低密度DArTseq技术开发的7449个SNP标记分析群体遗传多样性。利用STRUCTURE 2.3.4、主坐标分析(PCoA)、主成分判别分析(DAPC)、非加权算术平均对群法(UPGMA)和splitstreet等方法，对木桉居群中3个不同的遗传聚类进行了分析。单核苷酸多态性数据显示，冰孢和亚孢有明显的分类学差异。arcticum。然而，在c.a.b sp。在遗传聚类分析中，北极木居群中出现了两个亚群，它们是来自不同居群的个体的混合，这可能是基因流动的结果。
{"title":"Genetic structure of extant populations of Chrysanthemum arcticum L. and C. arcticum subsp. arcticum","authors":"Y. Liu, N. Anderson, A. Noyszewski","doi":"10.1139/as-2021-0029","DOIUrl":"https://doi.org/10.1139/as-2021-0029","url":null,"abstract":"Understanding the genetic diversity in natural plant populations is important in order to develop conservation strategies and utilize valuable germplasm resources. Chrysanthemum arcticum L., Arctic daisy, (=Arctanthemum arcticum; =Dendranthema arcticum) and its two subspecies (C. arcticum L. subsp. arcticum, C. arcticum L. subsp. polaré Hultén) are the only chrysanthemum species native to North America. We collected 529 individuals in nine C. arcticum and 21 C. a. subsp. arcticum populations from the state of Alaska mainland and Attu Island (the westernmost Aleutian Island). Evidence of declining population sizes and decreasing ranges of distribution were detected for both species and subspecies. Population genetic diversity was analyzed using 7,449 SNP markers developed using low density DArTseq technology. Three distinct genetic clusters within C. arcticum populations were detected by STRUCTURE 2.3.4, principal coordinate analysis (PCoA), discriminant analysis of principal components (DAPC), unweighted pair group method with arithmetic mean (UPGMA) and SplitsTree. SNP data showed a clear taxonomic distinction among C. arcticum and C. a. subsp. arcticum. However, within C. a. subsp. arcticum populations, two subgroups occurred in the genetic cluster analyses that were a mixture of individuals from different populations, which may be the result of gene flow.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45750175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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