| 1. |
- Bouchard, Frederic, et al.
(author)
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"Frozen-Ground Cartoons" : Permafrost comics as an innovative tool for polar outreach, education, and engagement
- 2018
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In: Polar Record. - : Cambridge University Press. - 0032-2474 .- 1475-3057. ; 54:5-6, s. 366-372
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Journal article (peer-reviewed)abstract
- Permafrost occupies 20 million square kilometres of Earth's high-latitude and high-altitude landscapes. These regions are sensitive to climate change and human activities; hence, permafrost research is of considerable scientific and societal importance. However, the results of this research are generally not known by the general public. Communicating scientific concepts is an increasingly important task in the research world. Different ways to engage learners and incorporate narratives in teaching materials exist, yet they are generally underused. Here we report on an international scientific outreach project called "Frozen-Ground Cartoons", which aims at making permafrost science accessible and fun for students, teachers, and parents through the creation of comic strips. We present the context in which the project was initiated, as well as recent education and outreach activities. The future phases of the project primarily involve a series of augmented reality materials, such as maps, photos, videos, and 3D drawings. With this project we aim to foster understanding of permafrost research among broader audiences, inspire future permafrost researchers, and raise public and science community awareness of polar science, education, outreach, and engagement.
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| 2. |
- Bruhn, Anders Dalhoff, et al.
(author)
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Terrestrial Dissolved Organic Matter Mobilized From Eroding Permafrost Controls Microbial Community Composition and Growth in Arctic Coastal Zones
- 2021
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In: Frontiers in Earth Science. - : Frontiers Media SA. - 2296-6463. ; 9
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Journal article (peer-reviewed)abstract
- Climate warming is accelerating erosion along permafrost-dominated Arctic coasts. This results in the additional supply of organic matter (OM) and nutrients into the coastal zone. In this study we investigate the impact of coastal erosion on the marine microbial community composition and growth rates in the coastal Beaufort Sea. Dissolved organic matter (DOM) derived from three representative glacial deposit types (fluvial, lacustrine, and moraine) along the Yukon coastal plain, Canada, were used as substrate to cultivate marine bacteria using a chemostat setup. Our results show that DOM composition (inferred from UV-Visible spectroscopy) and biodegradability (inferred from DOC concentration, bacterial production and respiration) significantly differ between the three glacial deposit types. DOM derived from fluvial and moraine types show clear terrestrial characteristics with low aromaticity (Sr: 0.63 ± 0.02 and SUVA254: 1.65 ± 0.06 L mg C−1 m−1 & Sr: 0.68 ± 0.01 and SUVA254: 1.17 ± 0.06 L mg C−1 m−1, respectively) compared to the lacustrine soil type (Sr: 0.71 ± 0.02 and SUVA254: 2.15 ± 0.05 L mg C−1 m−1). The difference in composition of DOM leads to the development of three different microbial communities. Whereas Alphaproteobacteria dominate in fluvial and lacustrine deposit types (67 and 87% relative abundance, respectively), Gammaproteobacteria is the most abundant class for moraine deposit type (88% relative abundance). Bacterial growth efficiency (BGE) is 66% for DOM from moraine deposit type, while 13 and 28% for DOM from fluvial and lacustrine deposit types, respectively. The three microbial communities therefore differ strongly in their net effect on DOM utilization depending on the eroded landscape type. The high BGE value for moraine-derived DOM is probably caused by a larger proportion of labile colorless DOM. These results indicate that the substrate controls marine microbial community composition and activities in coastal waters. This suggests that biogeochemical changes in the Arctic coastal zone will depend on the DOM character of adjacent deposit types, which determine the speed and extent of DOM mineralization and thereby carbon channeling into the microbial food web. We conclude that marine microbes strongly respond to the input of terrestrial DOM released by coastal erosion and that the landscape type differently influence marine microbes.
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| 3. |
- Lindgren, Amelie, et al.
(author)
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Millennial-scale analysis of land >23 ˚N as a carbon source and sink since the Last Glacial Maximum
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Other publication (other academic/artistic)abstract
- The transfers of carbon between land, ocean and atmosphere, and their relation to temperature variability over glacial and interglacial cycles continue to intrigue the scientific community. Over the past four decades, many have focused on the role of the Southern Ocean to explain the atmospheric carbon dioxide (CO2) patterns seen in ice core records, but recent advances also include mentions of a possible terrestrial component. We quantify important terrestrial organic soil carbon (C) stocks north of 23˚, using palaeo-data and modeled climate to reconstruct terrestrial C dynamics from the Last Glacial Maximum until present at millennial time steps. During the deglaciation, C storage declined to reach a minimum around 10 kyr BP, a trend which then turned and led to progressively higher soil C stocks during the Holocene. Net changes in mineral soil C stocks are small, even though significant geographic shifts occurred; instead, deglacial and interglacial terrestrial C stock dynamics are dominated by losses from permafrost loess, inundation of continental shelves and gains in peatlands, processes commonly overlooked in complex Earth System Models.
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| 4. |
- Speetjens, Niek Jesse, et al.
(author)
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Dissolved organic matter characterization in soils and streams in a small coastal low-Arctic catchment
- 2022
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In: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 19:12, s. 3073-3097
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Journal article (peer-reviewed)abstract
- Ongoing climate warming in the western Canadian Arctic is leading to thawing of permafrost soils and subsequent mobilization of its organic matter pool. Part of this mobilized terrestrial organic matter enters the aquatic system as dissolved organic matter (DOM) and is laterally transported from land to sea. Mobilized organic matter is an important source of nutrients for ecosystems, as it is available for microbial breakdown, and thus a source of greenhouse gases. We are beginning to understand spatial controls on the release of DOM as well as the quantities and fate of this material in large Arctic rivers. Yet, these processes remain systematically understudied in small, high-Arctic watersheds, despite the fact that these watersheds experience the strongest warming rates in comparison. Here, we sampled soil (active layer and permafrost) and water (porewater and stream water) from a small ice wedge polygon (IWP) catchment along the Yukon coast, Canada, during the summer of 2018. We assessed the organic carbon (OC) quantity (using dissolved (DOC) and particulate OC (POC) concentrations and soil OC content), quality (δ13C DOC, optical properties and source apportionment) and bioavailability (incubations; optical indices such as slope ratio, Sr; and humification index, HIX) along with stream water properties (temperature, T; pH; electrical conductivity, EC; and water isotopes). We classify and compare different landscape units and their soil horizons that differ in microtopography and hydrological connectivity, giving rise to differences in drainage capacity. Our results show that porewater DOC concentrations and yield reflect drainage patterns and waterlogged conditions in the watershed. DOC yield (in mg DOC g−1 soil OC) generally increases with depth but shows a large variability near the transition zone (around the permafrost table). Active-layer porewater DOC generally is more labile than permafrost DOC, due to various reasons (heterogeneity, presence of a paleo-active-layer and sampling strategies). Despite these differences, the very long transport times of porewater DOC indicate that substantial processing occurs in soils prior to release into streams. Within the stream, DOC strongly dominates over POC, illustrated by DOC/POC ratios around 50, yet storm events decrease that ratio to around 5. Source apportionment of stream DOC suggests a contribution of around 50 % from permafrost/deep-active-layer OC, which contrasts with patterns observed in large Arctic rivers (12 ± 8 %; Wild et al., 2019). Our 10 d monitoring period demonstrated temporal DOC patterns on multiple scales (i.e., diurnal patterns, storm events and longer-term trends), underlining the need for high-resolution long-term monitoring. First estimates of Black Creek annual DOC (8.2 ± 6.4 t DOC yr−1) and POC (0.21 ± 0.20 t yr−1) export allowed us to make a rough upscaling towards the entire Yukon Coastal Plain (34.51 ± 2.7 kt DOC yr−1 and 8.93 ± 8.5 kt POC yr−1). Rising Arctic temperatures, increases in runoff, soil organic matter (OM) leaching, permafrost thawing and primary production are likely to increase the net lateral OC flux. Consequently, altered lateral fluxes may have strong impacts on Arctic aquatic ecosystems and Arctic carbon cycling.
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| 5. |
- Tanski, George, et al.
(author)
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The Permafrost Young Researchers Network (PYRN) is getting older : The past, present, and future of our evolving community
- 2019
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In: Polar Record. - 0032-2474 .- 1475-3057. ; 55:4, s. 216-219
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Journal article (peer-reviewed)abstract
- A lasting legacy of the International Polar Year (IPY) 2007-2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. This research note summarises (1) PYRN's development since 2005 and the IPY's role, (2) the first 2015 PYRN census and survey results, and (3) PYRN's future plans to improve international and interdisciplinary exchange between young researchers. The review concludes that PYRN is an established network within the polar research community that has continually developed since 2005. PYRN's successful activities were largely fostered by IPY. With >200 of the 1200 registered members active and engaged, PYRN is capitalising on the availability of social media tools and rising to meet environmental challenges while maintaining its role as a successful network honouring the legacy of IPY.
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| 6. |
- Wagner, Julia, et al.
(author)
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High resolution mapping shows differences in soil carbon and nitrogen stocks in areas of varying landscape history in Canadian lowland tundra
- 2023
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In: Geoderma. - 0016-7061 .- 1872-6259. ; 438
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Journal article (peer-reviewed)abstract
- Soil organic carbon (SOC) in Arctic coastal polygonal tundra is vulnerable to climate change, especially in soils with occurrence of large amounts of ground ice. Pan-arctic studies of mapping SOC exist, yet they fail to describe the high spatial variability of SOC storage in permafrost landscapes. An important factor is the landscape history which determines landform development and consequently the spatial variability of SOC. Our aim was to map SOC stocks, and which environmental variables that determine SOC, in two adjacent coastal areas along Canadian Beaufort Sea coast with different glacial history. We used the machine learning technique random forest and environmental variables to map the spatial distribution of SOC stocks down to 1 m depth at a spatial resolution of 2 m for depth increments of 0-5, 5-15, 15-30, 30-60 and 60-100 cm. The results show that the two study areas had large differences in SOC stocks in the depth 60-100 cm due to high amounts of ground ice in one of the study areas. There are also differences in variable importance of the explanatory variables between the two areas. The area low in ground ice content had with 66.6 kg C/m(-2) more stored SOC than the area rich in ground ice content with 40.0 kg C/m(-2). However, this SOC stock could be potentially more vulnerable to climate change if ground ice melts and the ground subsides. The average N stock of the area low in ground ice is 3.77 kg m(-2) and of the area rich in ground ice is 3.83 kg m(-2). These findings support that there is a strong correlation between ground ice and SOC, with less SOC in ice-rich layers on a small scale. In addition to small scale studies of SOC mapping, detailed maps of ground ice content and distribution are needed for a validation of large-scale quantifications of SOC stocks and transferability of models.
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