| 1. |
- Palmtag, Juri, 1980-, et al.
(författare)
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Controls on the storage of organic carbon in permafrost soil in northern Siberia
- 2016
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Ingår i: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 67:4, s. 478-491
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Tidskriftsartikel (refereegranskat)abstract
- This research examined soil organic carbon (SOC), total nitrogen (TN) and aboveground phytomass carbon(PhC) stocks in two areas of the Taymyr Peninsula, northern Siberia.We combined field sampling, chemical and14C radiocarbon dating analyses with land cover classifications for landscape-level assessments. The estimatedmean for the 0–100-cm depth SOC stocks was 14.8 and 20.8 kgCm−2 in Ary-Mas and Logata, respectively. Thecorresponding values for TN were 1.0 and 1.3 kgNm−2. On average, about 2% only (range 0–12%) of the totalecosystem C is stored in PhC. In both study areas about 34% of the SOC at 0–100 cm is stored in cryoturbatedpockets, which have formed since at least the early Holocene. The larger carbon/nitrogen (C/N) ratio of thiscryoturbated material indicates that it consists of relatively undecomposed soil organic matter (SOM). Thereare substantial differences in SOC stocks and SOM properties within and between the two study areas, whichemphasizes the need to consider both geomorphology and soil texture in the assessment of landscape-level andregional SOC stocks.Highlights• This research addresses landscape-scale and regional variation in SOC stocks.• Landform and soil texture are taken into account in the analysis.• The contribution of phytomass to total ecosystem C stored is limited.• Large SOC stocks are susceptible to decomposition following permafrost thaw.
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| 2. |
- Ramage, Justine L., et al.
(författare)
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Distribution of carbon and nitrogen along hillslopes in three valleys on Herschel Island, Yukon Territory, Canada
- 2019
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Ingår i: Catena (Cremlingen. Print). - : Elsevier BV. - 0341-8162 .- 1872-6887. ; 178, s. 132-140
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Tidskriftsartikel (refereegranskat)abstract
- Thermokarst results from the thawing of ice-rich permafrost and alters the biogeochemical cycling in the Arctic by reworking soil material and redistributing soil organic carbon (SOC) and total nitrogen (TN) along uplands, hillslopes, and lowlands. Understanding the impact of this redistribution is key to better estimating the storage of SOC in permafrost terrains. However, there are insufficient studies quantifying long-term impacts of thaw processes on the distribution of SOC and TN along hillslopes. We address this issue by providing estimates of SOC and TN stocks along the hillslopes of three valleys located on Herschel Island (Yukon, Canada), and by discussing the impact of hillslope thermokarst on the variability of SOC and TN stocks. We found that the average SOC and TN 0-100 cm stocks in the valleys were 26.4 +/- 8.9 kg C m(-2) and 2.1 +/- 0.6 kg N m(-2). We highlight the strong variability in the soils physical and geochemical properties within hillslope positions. High SOC stocks were found at the summits, essentially due to burial of organic matter by cryoturbation, and at the toeslopes due to impeded drainage which favored peat formation and SOC accumulation. The average carbon-to-nitrogen ratio in the valleys was 12.9, ranging from 9.7 to 18.9, and was significantly higher at the summits compared to the backslopes and footslopes (p < 0.05), suggesting a degradation of SOC downhill. Carbon and nitrogen contents and stocks were significantly lower on 16% of the sites that were previously affected by hillslope thermokarst (p < 0.05). Our results showed that lateral redistribution of SOC and TN due to hillslope thermokarst has a strong impact on the SOC storage in ice-rich permafrost terrains.
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| 3. |
- Ramage, Justine, et al.
(författare)
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'No longer solid' : perceived impacts of permafrost thaw in three Arctic communities
- 2022
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Ingår i: Polar Geography. - 1088-937X .- 1939-0513. ; 45:3, s. 226-239
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Tidskriftsartikel (refereegranskat)abstract
- Permafrost characterizes ground conditions in most of the Arctic and is increasingly thawing. While environmental consequences of permafrost thaw are under intense scrutiny by natural and life sciences, social sciences' studies on local communities' perceptions of change is thus far limited. This hinders the development of targeted adaptation and mitigation measures. We present the results of a survey on communities' perceptions of permafrost thaw, with a focus on subsistence activities, carried out between 2019 and 2020 in Aklavik (Northwest Territories, Canada), Longyearbyen (Svalbard, Norway), and Qeqertarsuaq (Qeqertalik Municipality, Greenland). Results show that the majority of the 237 participants are well aware of the consequences of permafrost thaw on the landscape as well as the connection between increased air temperature and permafrost thaw. The majority perceive permafrost thaw negatively although they do not perceive it as a challenge in all life domains. Permafrost thaw is perceived as a major cause for challenges in subsistence activities, infrastructure, and the physical environment. Different perceptions within the three study communities suggests that perceptions of thaw are not solely determined by physical changes but also influenced by factors related to the societal context, including discourses of climate change, cultural background, and land use.
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| 4. |
- Ramage, Justine, 1988-, et al.
(författare)
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The Net GHG Balance and Budget of the Permafrost Region (2000–2020) From Ecosystem Flux Upscaling
- 2024
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Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 38:4
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Tidskriftsartikel (refereegranskat)abstract
- The northern permafrost region has been projected to shift from a net sink to a net source of carbon under global warming. However, estimates of the contemporary net greenhouse gas (GHG) balance and budgets of the permafrost region remain highly uncertain. Here, we construct the first comprehensive bottom-up budgets of CO2, CH4, and N2O across the terrestrial permafrost region using databases of more than 1000 in situ flux measurements and a land cover-based ecosystem flux upscaling approach for the period 2000–2020. Estimates indicate that the permafrost region emitted a mean annual flux of 12 (−606, 661) Tg CO2–C yr−1, 38 (22, 53) Tg CH4–C yr−1, and 0.67 (0.07, 1.3) Tg N2O–N yr−1 to the atmosphere throughout the period. Thus, the region was a net source of CH4 and N2O, while the CO2 balance was near neutral within its large uncertainties. Undisturbed terrestrial ecosystems had a CO2 sink of −340 (−836, 156) Tg CO2–C yr−1. Vertical emissions from fire disturbances and inland waters largely offset the sink in vegetated ecosystems. When including lateral fluxes for a complete GHG budget, the permafrost region was a net source of C and N, releasing 144 (−506, 826) Tg C yr−1 and 3 (2, 5) Tg N yr−1. Large uncertainty ranges in these estimates point to a need for further expansion of monitoring networks, continued data synthesis efforts, and better integration of field observations, remote sensing data, and ecosystem models to constrain the contemporary net GHG budgets of the permafrost region and track their future trajectory.
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| 5. |
- Tanski, George, et al.
(författare)
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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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Ingår i: Polar Record. - 0032-2474 .- 1475-3057. ; 55:4, s. 216-219
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Tidskriftsartikel (refereegranskat)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. |
- Timlin, Ulla, et al.
(författare)
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Self-Rated Health, Life Balance and Feeling of Empowerment When Facing Impacts of Permafrost Thaw-A Case Study from Northern Canada
- 2022
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Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 13:5
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming in Arctic Canada, e.g., permafrost thaw, comprehensively impacts biota and the environment, which then affects the lives of people. This study aimed to investigate which perceived environmental and adaptation factors relate to self-rated well-being, quality of life, satisfaction with life (sum variable = life balance), self-rated health, and feeling of empowerment to face the changes related to permafrost thaw. The study sample was collected from one community using a questionnaire (n = 53) and analyzed by cross-tabulation. Results indicated that most participants had at least good well-being, quality of life, satisfaction with life, and a medium level of health, and over 40% assessed being empowered to face the changes related to permafrost thaw. Problems and challenges associated with permafrost thaw, e.g., health, traditional lifeways, and infrastructure, were recognized; these had impacts on life balance, feeling of empowerment, and self-rated health. Traditional knowledge regarding adaptation to face changes was seen as important. More adaptation actions from the individual to global level seemed to be needed. This study provides an overview of the situation in one area, but more research, with a larger study sample, should be conducted to achieve a deeper understanding of climate-related impacts on life and holistic well-being.
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