K. P. Ryan, S. Petersen, S. Ferguson, C‐Jae Breiter, C. Watt
Beluga whale (Delphinapterus leucas) movements, habitat use, and diving behavior have been studied using satellite-linked transmitters for decades. The inaccessibility of Arctic and subarctic habitats makes these instruments especially valuable for beluga research. The long-term effects that tags and tag attachments have on belugas, however, are not well known because resightings occur relatively infrequently. Here, we describe two belugas photographed during photographic monitoring programs of two populations: western Hudson Bay and Cumberland Sound. The beluga photographed in western Hudson Bay had scars consistent with the tag pins migrating out, which is thought to occur when the tag is pulled posteriorly due to drag. The beluga photographed in Cumberland Sound had all three tag pins still in place 11-21 years after they were inserted. Both whales appeared to be in good body condition with no evidence of infection, and the beluga from Cumberland Sound was accompanied by a one-year-old calf. Resightings of previously tagged whales are infrequent for the western Hudson Bay population and have never been documented in Cumberland Sound. However, through long-term photographic monitoring programs, additional sightings may provide more information regarding the method of tag loss and the long-term effects of tagging on whale health and productivity.
{"title":"Photographic evidence of tagging impacts for two beluga whales from the Cumberland Sound and western Hudson Bay populations","authors":"K. P. Ryan, S. Petersen, S. Ferguson, C‐Jae Breiter, C. Watt","doi":"10.1139/as-2021-0032","DOIUrl":"https://doi.org/10.1139/as-2021-0032","url":null,"abstract":"Beluga whale (Delphinapterus leucas) movements, habitat use, and diving behavior have been studied using satellite-linked transmitters for decades. The inaccessibility of Arctic and subarctic habitats makes these instruments especially valuable for beluga research. The long-term effects that tags and tag attachments have on belugas, however, are not well known because resightings occur relatively infrequently. Here, we describe two belugas photographed during photographic monitoring programs of two populations: western Hudson Bay and Cumberland Sound. The beluga photographed in western Hudson Bay had scars consistent with the tag pins migrating out, which is thought to occur when the tag is pulled posteriorly due to drag. The beluga photographed in Cumberland Sound had all three tag pins still in place 11-21 years after they were inserted. Both whales appeared to be in good body condition with no evidence of infection, and the beluga from Cumberland Sound was accompanied by a one-year-old calf. Resightings of previously tagged whales are infrequent for the western Hudson Bay population and have never been documented in Cumberland Sound. However, through long-term photographic monitoring programs, additional sightings may provide more information regarding the method of tag loss and the long-term effects of tagging on whale health and productivity.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49598630","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}
Sarah B. Gutzmann, E. Hodgson, D. Braun, J. Moore, R. Hovel
Many small-scale fisheries are remote in nature, making data collection logistically difficult. Thus, there is a need for accessible solutions that address the data gaps present in these fisheries. One possible solution is to incorporate photography into community- or harvest-based monitoring frameworks and employ these images to estimate biological data. Here we test this approach using łuk dagaii, or broad whitefish, Coregonus nasus (Pallus 1776) in the Gwich’in Settlement Area, a remote region in the Mackenzie River system in Canada’s Northwest Territories. We used photographs taken by Gwich’in collaborators using a simple, standardized set-up to ask the question: how accurately can weight be estimated from a photo? Using random forest models based on morphometric photograph measurements as well as season and location of harvest, we predicted broad whitefish weight to within 13% of true weight (257 g, for fish weighing an average of 2036 g). The model predictions were well distributed in their residuals for most fish, though we discuss biases at low and high weights. Image analysis is a simple, low cost, and accessible method that may contribute to ongoing, community/harvest-based fishery data collection where fish length (measured) and weight (predicted) can be tracked through time.
{"title":"Predicting fish weight using photographic image analysis: a case study of broad whitefish in the lower Mackenzie River watershed","authors":"Sarah B. Gutzmann, E. Hodgson, D. Braun, J. Moore, R. Hovel","doi":"10.1139/as-2021-0017","DOIUrl":"https://doi.org/10.1139/as-2021-0017","url":null,"abstract":"Many small-scale fisheries are remote in nature, making data collection logistically difficult. Thus, there is a need for accessible solutions that address the data gaps present in these fisheries. One possible solution is to incorporate photography into community- or harvest-based monitoring frameworks and employ these images to estimate biological data. Here we test this approach using łuk dagaii, or broad whitefish, Coregonus nasus (Pallus 1776) in the Gwich’in Settlement Area, a remote region in the Mackenzie River system in Canada’s Northwest Territories. We used photographs taken by Gwich’in collaborators using a simple, standardized set-up to ask the question: how accurately can weight be estimated from a photo? Using random forest models based on morphometric photograph measurements as well as season and location of harvest, we predicted broad whitefish weight to within 13% of true weight (257 g, for fish weighing an average of 2036 g). The model predictions were well distributed in their residuals for most fish, though we discuss biases at low and high weights. Image analysis is a simple, low cost, and accessible method that may contribute to ongoing, community/harvest-based fishery data collection where fish length (measured) and weight (predicted) can be tracked through time.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46599726","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. Walker, M. Raynolds, M. Kanevskiy, Yuri S. Shur, V. Romanovsky, B. Jones, M. Buchhorn, M. Jorgenson, J. Šibík, A. Breen, A. Kade, Emily Watson-Cook, H. Bergstedt, A. Liljedahl, R. Daanen, B. Connor, D. Nicolsky, J. Peirce
Environmental impact assessments for new Arctic infrastructure do not adequately consider the likely long-term cumulative effects of climate change and infrastructure to landforms and vegetation in areas with ice-rich permafrost. This is due in part to lack of long-term environmental studies that monitor changes after infrastructure is built. This case study examines long-term (1949–2020) climate- and road-related changes in a network of ice-wedge polygons, Prudhoe Bay Oilfield, Alaska. We studied four trajectories of change along a heavily traveled road and a relatively remote site. During 20 years prior to oilfield development, the climate and landscapes changed very little. During 50 years after development, climate-related changes included increased numbers thermokarst ponds, changes to ice-wedge-polygon morphology, snow distribution, thaw depths, dominant vegetation types, and shrub abundance. Road dust strongly affected plant-community structure and composition, particularly small forbs, mosses, and lichens. Flooding increased permafrost degradation, polygon center-trough elevation contrasts, and vegetation productivity. It was not possible to isolate infrastructure impacts from climate impacts, but the combined datasets provide unique insights into the rate and extent of ecological disturbances associated with infrastructure-affected landscapes under decades of climate warming. We conclude with recommendations for future cumulative impact assessments in areas with ice-rich permafrost.
{"title":"Cumulative impacts of a gravel road and climate change in an ice-wedge polygon landscape, Prudhoe Bay, AK","authors":"D. Walker, M. Raynolds, M. Kanevskiy, Yuri S. Shur, V. Romanovsky, B. Jones, M. Buchhorn, M. Jorgenson, J. Šibík, A. Breen, A. Kade, Emily Watson-Cook, H. Bergstedt, A. Liljedahl, R. Daanen, B. Connor, D. Nicolsky, J. Peirce","doi":"10.1139/as-2021-0014","DOIUrl":"https://doi.org/10.1139/as-2021-0014","url":null,"abstract":"Environmental impact assessments for new Arctic infrastructure do not adequately consider the likely long-term cumulative effects of climate change and infrastructure to landforms and vegetation in areas with ice-rich permafrost. This is due in part to lack of long-term environmental studies that monitor changes after infrastructure is built. This case study examines long-term (1949–2020) climate- and road-related changes in a network of ice-wedge polygons, Prudhoe Bay Oilfield, Alaska. We studied four trajectories of change along a heavily traveled road and a relatively remote site. During 20 years prior to oilfield development, the climate and landscapes changed very little. During 50 years after development, climate-related changes included increased numbers thermokarst ponds, changes to ice-wedge-polygon morphology, snow distribution, thaw depths, dominant vegetation types, and shrub abundance. Road dust strongly affected plant-community structure and composition, particularly small forbs, mosses, and lichens. Flooding increased permafrost degradation, polygon center-trough elevation contrasts, and vegetation productivity. It was not possible to isolate infrastructure impacts from climate impacts, but the combined datasets provide unique insights into the rate and extent of ecological disturbances associated with infrastructure-affected landscapes under decades of climate warming. We conclude with recommendations for future cumulative impact assessments in areas with ice-rich permafrost.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44375687","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}
O. P. Vindstad, J. U. Jepsen, Helge Molvig, R. Ims
Climate warming allows generalist boreal consumers to expand into Arctic ecosystems. We present experimental and observational field data showing that a generalist boreal insect pest—the winter moth (Operophtera brumata Linnaeus, 1758)—is expanding its outbreak range out of the northern boreal mountain birch forest in northeast Fennoscandia and into the adjacent Low Arctic shrub tundra. This is the first documented example of an outbreaking boreal insect pest expanding into a tundra ecosystem. The expansion has coincided with a long-term advancing trend in the expected hatching date of moth eggs in spring for the study region. We show that the winter moth can complete development on Low Arctic willows and that the density of winter moth larvae in willow thickets is unrelated to the amount of mountain birch (the main host plant in northern boreal forest) in the thickets. However, we also demonstrate that larval densities on willows show a regional-scale spatial decline when moving away from the birch forest and into the shrub tundra. Continued monitoring is needed to establish whether the outbreaks will spread farther into the tundra. The expansion of outbreaking boreal pests into the tundra could alter conventional expectations of increasing vegetation productivity and shrubification in tundra ecosystems.
{"title":"A pioneering pest: the winter moth (Operophtera brumata) is expanding its outbreak range into Low Arctic shrub tundra","authors":"O. P. Vindstad, J. U. Jepsen, Helge Molvig, R. Ims","doi":"10.1139/as-2021-0027","DOIUrl":"https://doi.org/10.1139/as-2021-0027","url":null,"abstract":"Climate warming allows generalist boreal consumers to expand into Arctic ecosystems. We present experimental and observational field data showing that a generalist boreal insect pest—the winter moth (Operophtera brumata Linnaeus, 1758)—is expanding its outbreak range out of the northern boreal mountain birch forest in northeast Fennoscandia and into the adjacent Low Arctic shrub tundra. This is the first documented example of an outbreaking boreal insect pest expanding into a tundra ecosystem. The expansion has coincided with a long-term advancing trend in the expected hatching date of moth eggs in spring for the study region. We show that the winter moth can complete development on Low Arctic willows and that the density of winter moth larvae in willow thickets is unrelated to the amount of mountain birch (the main host plant in northern boreal forest) in the thickets. However, we also demonstrate that larval densities on willows show a regional-scale spatial decline when moving away from the birch forest and into the shrub tundra. Continued monitoring is needed to establish whether the outbreaks will spread farther into the tundra. The expansion of outbreaking boreal pests into the tundra could alter conventional expectations of increasing vegetation productivity and shrubification in tundra ecosystems.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48393084","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}
Ice patches are ubiquitous in polar regions and are a key element for landscape evolution. We present new insights into polar desert ice patch formation based on snow and ice properties at Ward Hunt Island (Canadian High Arctic, 83°N). Our results demonstrate that ice patches are composed of two distinct units. The upper unit is characterized by very fine granular and bubbly ice with a clear oblique layering. By contrast, the lower unit is strikingly different with coarse crystals, lower porosity, and a high frequency of fractures. For both units, superimposed ice formation at the base of the deep snowpack stands out as the primary ice aggradation process. The distinct properties of the lower unit likely result from a long period of kinetic ice crystal growth indicating a minimum age of several hundred years. A radiocarbon date of 3 487 ± 20 cal BP suggests that ice patches could potentially date back to the late Holocene. This old ice was recently truncated during warmer summers between 2008 and 2012, but the ice patch quickly recovered its volume during cooler summers. The old age of the ice patches and their rapid regeneration after melt events suggest their resilience to current warmer summers.
冰片在极地地区普遍存在，是景观演变的关键因素。我们提出了基于Ward Hunt岛(加拿大高纬度北极，83°N)冰雪特性的极地沙漠冰片形成的新见解。我们的研究结果表明，冰块由两个不同的单元组成。上部单元的特征是非常细的颗粒状和气泡状冰，具有明显的斜分层。相比之下，下部单元则明显不同，晶体粗，孔隙度低，裂缝频率高。对于这两个单元来说，深积雪底部的叠加冰形成是主要的冰堆积过程。较低单元的独特性质可能是由于长时间的动态冰晶生长导致的，这表明至少有几百年的年龄。3 487±20 cal BP的放射性碳测年表明，冰斑可能可以追溯到全新世晚期。在2008年至2012年的温暖夏季，这些古老的冰被截断了，但在凉爽的夏季，冰片迅速恢复了体积。冰原的年龄和它们在融化事件后的快速再生表明它们对当前更温暖的夏季的适应能力。
{"title":"Properties and stratigraphy of polar ice patches in the Canadian High Arctic reveal their current resilience to warm summers","authors":"Gautier Davesne, David H. Fortier, F. Dominé","doi":"10.1139/as-2021-0011","DOIUrl":"https://doi.org/10.1139/as-2021-0011","url":null,"abstract":"Ice patches are ubiquitous in polar regions and are a key element for landscape evolution. We present new insights into polar desert ice patch formation based on snow and ice properties at Ward Hunt Island (Canadian High Arctic, 83°N). Our results demonstrate that ice patches are composed of two distinct units. The upper unit is characterized by very fine granular and bubbly ice with a clear oblique layering. By contrast, the lower unit is strikingly different with coarse crystals, lower porosity, and a high frequency of fractures. For both units, superimposed ice formation at the base of the deep snowpack stands out as the primary ice aggradation process. The distinct properties of the lower unit likely result from a long period of kinetic ice crystal growth indicating a minimum age of several hundred years. A radiocarbon date of 3 487 ± 20 cal BP suggests that ice patches could potentially date back to the late Holocene. This old ice was recently truncated during warmer summers between 2008 and 2012, but the ice patch quickly recovered its volume during cooler summers. The old age of the ice patches and their rapid regeneration after melt events suggest their resilience to current warmer summers.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44617718","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 essential oils of the widely distributed boreal/Arctic dwarf shrub, Rhododendron tomentosum ssp. subarcticum (Harmaja) G.D. Wallace, have important ecological, cultural, medicinal, and commercial roles. To understand the relationship between resource limitation and essential oil content of this species we measured the amount and diversity of terpenes from shoots of plants exposed to a 14-year ecosystem resource manipulation experiment in Arctic Alaska. Treatments tested interactive effects of nitrogen (N) and phosphorus (P) addition, warming and N + P fertilization, and shading and N + P fertilization. The controls and NP fertilization had the highest essential oil content, whereas shading and P addition had less than 20% of the control content. Warming reduced essential oil content to <65% of that of the controls. Essential oil components varied greatly among the treatments, with significant differences in the expression of specific essential oil components. Large changes in plant community composition and ecosystem structure in response to treatments likely played a large role in the response of R. tomentosum. Our data suggest that resource changes in response to climate warming and its secondary effects on light and nutrient availability have the potential to change the profiles of essential oils in R. tomentosum, with important ecological and cultural impacts.
{"title":"Essential oil content of Rhododendron tomentosum responds strongly to manipulation of ecosystem resources in Arctic Alaska","authors":"Tracey A. Baldwin, S. Oberbauer","doi":"10.1139/as-2020-0055","DOIUrl":"https://doi.org/10.1139/as-2020-0055","url":null,"abstract":"The essential oils of the widely distributed boreal/Arctic dwarf shrub, Rhododendron tomentosum ssp. subarcticum (Harmaja) G.D. Wallace, have important ecological, cultural, medicinal, and commercial roles. To understand the relationship between resource limitation and essential oil content of this species we measured the amount and diversity of terpenes from shoots of plants exposed to a 14-year ecosystem resource manipulation experiment in Arctic Alaska. Treatments tested interactive effects of nitrogen (N) and phosphorus (P) addition, warming and N + P fertilization, and shading and N + P fertilization. The controls and NP fertilization had the highest essential oil content, whereas shading and P addition had less than 20% of the control content. Warming reduced essential oil content to <65% of that of the controls. Essential oil components varied greatly among the treatments, with significant differences in the expression of specific essential oil components. Large changes in plant community composition and ecosystem structure in response to treatments likely played a large role in the response of R. tomentosum. Our data suggest that resource changes in response to climate warming and its secondary effects on light and nutrient availability have the potential to change the profiles of essential oils in R. tomentosum, with important ecological and cultural impacts.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42685542","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}
C. Rixen, T. Høye, P. Macek, R. Aerts, J. Alatalo, J. Andeson, P. Arnold, I. Barrio, J. Bjerke, Mats P. Björkman, D. Blok, G. Blume‐Werry, J. Boike, S. Bokhorst, M. Carbognani, C. Christiansen, P. Convey, E. Cooper, J. Cornelissen, S. Coulson, E. Dorrepaal, B. Elberling, S. Elmendorf, Cassandra Elphinstone, T. Forte, E. Frei, Sonya R. Geange, Friederike Gehrmann, C. Gibson, P. Grogan, Aud Halbritter Rechsteiner, J. Harte, G. Henry, D. Inouye, Rebecca E. Irwin, G. Jespersen, I. Jónsdóttir, J. Jung, D. Klinges, G. Kudo, Juho Lämsä, Hanna Lee, J. Lembrechts, Signe Lett, J. Lynn, Hjalte M. R. Mann, M. Mastepanov, J. Morse, I. Myers-Smith, J. Olofsson, Riku Paavola, A. Petraglia, G. Phoenix, P. Semenchuk, M. Siewert, R. Slatyer, M. Spasojevic, K. Suding, P. Sullivan, K. Thompson, M. Väisänen, V. Vandvik, S. Venn, Josefine Walz, R. Way, J. Welker, S. Wipf, Shengwei Zong
Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, plant-animal interactions, permafrost conditions, microbial processes and biogeochemical cycling. We also compare studies of natural snow gradients with snow manipulation studies, altering snow depth and duration, to assess time scale difference of these approaches. The number of studies on snow in tundra ecosystems has increased considerably in recent years, yet we still lack a comprehensive overview of how altered snow conditions will affect these ecosystems. In specific, we found a mismatch in the timing of snowmelt when comparing studies of natural snow gradients with snow manipulations. We found that snowmelt timing achieved by manipulative studies (average 7.9 days advance, 5.5 days delay) were substantially lower than those observed over spatial gradients (mean range of 56 days) or due to interannual variation (mean range of 32 days). Differences between snow study approaches need to be accounted for when projecting snow dynamics and their impact on ecosystems in future climates.
{"title":"Winters are changing: snow effects on Arctic and alpine tundra ecosystems","authors":"C. Rixen, T. Høye, P. Macek, R. Aerts, J. Alatalo, J. Andeson, P. Arnold, I. Barrio, J. Bjerke, Mats P. Björkman, D. Blok, G. Blume‐Werry, J. Boike, S. Bokhorst, M. Carbognani, C. Christiansen, P. Convey, E. Cooper, J. Cornelissen, S. Coulson, E. Dorrepaal, B. Elberling, S. Elmendorf, Cassandra Elphinstone, T. Forte, E. Frei, Sonya R. Geange, Friederike Gehrmann, C. Gibson, P. Grogan, Aud Halbritter Rechsteiner, J. Harte, G. Henry, D. Inouye, Rebecca E. Irwin, G. Jespersen, I. Jónsdóttir, J. Jung, D. Klinges, G. Kudo, Juho Lämsä, Hanna Lee, J. Lembrechts, Signe Lett, J. Lynn, Hjalte M. R. Mann, M. Mastepanov, J. Morse, I. Myers-Smith, J. Olofsson, Riku Paavola, A. Petraglia, G. Phoenix, P. Semenchuk, M. Siewert, R. Slatyer, M. Spasojevic, K. Suding, P. Sullivan, K. Thompson, M. Väisänen, V. Vandvik, S. Venn, Josefine Walz, R. Way, J. Welker, S. Wipf, Shengwei Zong","doi":"10.1139/as-2020-0058","DOIUrl":"https://doi.org/10.1139/as-2020-0058","url":null,"abstract":"Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, plant-animal interactions, permafrost conditions, microbial processes and biogeochemical cycling. We also compare studies of natural snow gradients with snow manipulation studies, altering snow depth and duration, to assess time scale difference of these approaches. The number of studies on snow in tundra ecosystems has increased considerably in recent years, yet we still lack a comprehensive overview of how altered snow conditions will affect these ecosystems. In specific, we found a mismatch in the timing of snowmelt when comparing studies of natural snow gradients with snow manipulations. We found that snowmelt timing achieved by manipulative studies (average 7.9 days advance, 5.5 days delay) were substantially lower than those observed over spatial gradients (mean range of 56 days) or due to interannual variation (mean range of 32 days). Differences between snow study approaches need to be accounted for when projecting snow dynamics and their impact on ecosystems in future climates.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41797991","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. Wilson, S. Sonsthagen, Philip Lavretsky, A. Majewski, E. Árnason, Katrín Halldórsdóttir, A. W. Einarsson, K. Wedemeyer, S. Talbot
As marine ecosystems respond to climate change and other stressors, it is necessary to evaluate current and past hybridization events to gain insight on the outcomes and drivers of such events. Ancestral introgression within the gadids has been suggested to allow cod to inhabit a variety of habitats. Little attention has been given to contemporary hybridization especially within cold-water adapted cod (Boreogadus saida and Arctogadus glacialis). We used whole-genome, restriction-site associated, and mitochondrial sequence data to explore the degree and direction of hybridization between these species where previous hybridization had not been reported. Although nearly identical morphologically at certain life stages, we detected very distinct nuclear and mitochondrial lineages. We detected one potential hybrid with a Arctogadus mitochondrial haplotype and Boreogadus nuclear genotype, but no early generational hybrids. The presence of a late generation hybrid suggests that at least some hybrids survive to maturity and reproduce. However, a historical introgression event could not be excluded. Contemporary gene flow appears asymmetrical from Arctogadus into Boreogadus which may be due to overlap in timing of spawning, environmental heterogeneity, or differences in population size. This study provides important baseline information for the degree of potential hybridization between these species within Alaska marine environments.
{"title":"Low levels of hybridization between sympatric cold-water adapted Arctic cod and Polar cod in Beaufort Sea confirms genetic distinctiveness","authors":"R. Wilson, S. Sonsthagen, Philip Lavretsky, A. Majewski, E. Árnason, Katrín Halldórsdóttir, A. W. Einarsson, K. Wedemeyer, S. Talbot","doi":"10.1139/as-2021-0030","DOIUrl":"https://doi.org/10.1139/as-2021-0030","url":null,"abstract":"As marine ecosystems respond to climate change and other stressors, it is necessary to evaluate current and past hybridization events to gain insight on the outcomes and drivers of such events. Ancestral introgression within the gadids has been suggested to allow cod to inhabit a variety of habitats. Little attention has been given to contemporary hybridization especially within cold-water adapted cod (Boreogadus saida and Arctogadus glacialis). We used whole-genome, restriction-site associated, and mitochondrial sequence data to explore the degree and direction of hybridization between these species where previous hybridization had not been reported. Although nearly identical morphologically at certain life stages, we detected very distinct nuclear and mitochondrial lineages. We detected one potential hybrid with a Arctogadus mitochondrial haplotype and Boreogadus nuclear genotype, but no early generational hybrids. The presence of a late generation hybrid suggests that at least some hybrids survive to maturity and reproduce. However, a historical introgression event could not be excluded. Contemporary gene flow appears asymmetrical from Arctogadus into Boreogadus which may be due to overlap in timing of spawning, environmental heterogeneity, or differences in population size. This study provides important baseline information for the degree of potential hybridization between these species within Alaska marine environments.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42308094","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}
Snow cover is a key component in Arctic ecosystems and will likely be affected by changes in winter precipitation. Increased snow depth and consequent later snowmelt leads to greater microbial mineralization in winter, improving soil and vegetation nutrient status. We studied areas with naturally differing snow depths and date of snowmelt in Adventdalen, Svalbard. Soil properties, plant leaf nutrient status and species composition along with vegetation indices (NDVI) were compared for three snowmelt regimes (Early, Mid and Late). We showed 1) Late regimes (snow beds) had wetter soils, higher pH and leaves of Bistorta vivipara and Salix polaris had higher concentration of nutrients (nitrogen and δ15N). Little to no difference was found in soil nutrient concentrations between snowmelt regimes. 2) Late regimes had highest NDVI values, while those of Early and Mid regimes were similar 3) vegetation composition differed between Early and Late regimes, with Dryas octopetala and Luzula arcuata subsp. confusa characterizing the former and Equisetum arvense and Eriophorum scheuchzeri the latter. 4) Trends for plant nutrients contents were similar to those found in a nearby snow manipulation experiment. Snow distribution and time of snowmelt played an important role in determining regional environmental heterogeneity, patchiness in plant community distribution, their species composition and plant phenology.
{"title":"Natural variation in snow depth and snow melt timing in the High Arctic have implications for soil and plant nutrient status and vegetation composition","authors":"Mikel Moriana-Armendariz, L. Nilsen, E. Cooper","doi":"10.1139/as-2020-0025","DOIUrl":"https://doi.org/10.1139/as-2020-0025","url":null,"abstract":"Snow cover is a key component in Arctic ecosystems and will likely be affected by changes in winter precipitation. Increased snow depth and consequent later snowmelt leads to greater microbial mineralization in winter, improving soil and vegetation nutrient status. We studied areas with naturally differing snow depths and date of snowmelt in Adventdalen, Svalbard. Soil properties, plant leaf nutrient status and species composition along with vegetation indices (NDVI) were compared for three snowmelt regimes (Early, Mid and Late). We showed 1) Late regimes (snow beds) had wetter soils, higher pH and leaves of Bistorta vivipara and Salix polaris had higher concentration of nutrients (nitrogen and δ15N). Little to no difference was found in soil nutrient concentrations between snowmelt regimes. 2) Late regimes had highest NDVI values, while those of Early and Mid regimes were similar 3) vegetation composition differed between Early and Late regimes, with Dryas octopetala and Luzula arcuata subsp. confusa characterizing the former and Equisetum arvense and Eriophorum scheuchzeri the latter. 4) Trends for plant nutrients contents were similar to those found in a nearby snow manipulation experiment. Snow distribution and time of snowmelt played an important role in determining regional environmental heterogeneity, patchiness in plant community distribution, their species composition and plant phenology.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48084627","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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