Centennial scale environmental change at key arctic observational sites

2020 ◽  
Author(s):  
Torben Røjle Christensen ◽  
Kerstin Rasmussen ◽  
Jakob Abermann ◽  
Katrine Raundrup ◽  
Kirsten Christoffersen ◽  
...  
Keyword(s):  
High Arctic ◽  
Ecosystem Dynamics ◽  
The Arctic ◽  
Base Line ◽  
Historical Sources ◽  
Ecosystem Monitoring ◽  
Decadal Scale ◽  
Frequency Monitoring ◽  
Low Arctic ◽  
The Individual

<p>The Arctic is changing in response to ongoing warming. Multiple effects have been documented in terms of sea-ice distribution, land-ice volume and ecosystems both in the marine and terrestrial realm, which are clear responses to the overall global warming. Targeted efforts documenting individual components of the arctic system build the base-line for quantification of these effects.</p><p>Comprehensive ecosystem observational programs covering both glacial, terrestrial and marine components are rare in the Arctic but one such, the Greenland Ecosystem Monitoring (GEM) program, has now been operational for nearly 25 years at three main sites in Greenland. Zackenberg valley and Young Sund in NE Greenland is representing the high-arctic environment, Disko Island on the central west coast of Greenland at the border between the high and the low-arctic and Nuuk-Kobbefjord in SW Greenland the low-arctic.</p><p>The GEM program at all three sites cover inter-annual variation in ecosystem dynamics of glacial, terrestrial and marine ecosystems with data gathered from more than 2000 parameters some of which being automatically recorded at very high frequencies (up  to 20 Hz for micro-meteorological measurements). This present-day detailed, comprehensive and high-frequency monitoring of ecosystem dynamics calls for the question: Which historical sources may be used in order to anchor the environmental status of the monitored areas back in time?</p><p>For the composite landscape dynamics including glacier, terrestrial and near-coastal environments it is of great value to study visual, mainly photographic evidences that are available from different parts of the portfolio of arctic exploration during the 19<sup>th</sup> and 20<sup>th</sup> centuries. We will in this presentation review available historical archival data (early photographs, paintings, drawings) from the GEM monitoring locations and their immediate surroundings.</p><p>The different historical setting over the centennial timescale is briefly discussed and particular illustrative records from the individual sites are shown. The evidence of change hereby shown at the centennial time scale is evaluated in the perspective of results from decadal scale present day monitoring.</p>

Revision of the life history of the High Arctic moth Gynaephora groenlandica (Wocke) (Lepidoptera: Lymantriidae)

1998 ◽  
Vol 76 (7) ◽  
pp. 1371-1381 ◽  
Author(s):  
W Dean Morewood ◽  
Richard A Ring
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Head Capsule ◽  
High Arctic ◽  
The Arctic ◽  
Base Line ◽  
Laboratory Rearing ◽  
History Information ◽  
History Of ◽  
Gynaephora Groenlandica

Many studies have explored the adaptations of arctic and alpine Gynaephora species (Lepidoptera: Lymantriidae) to their environment, and base-line life-history information is important for the interpretation of such studies. Data and observations on G. groenlandica (Wocke) collected in recent years at Alexandra Fiord, Ellesmere Island, Canada, contradict some of the life-history information previously published for this species from the same site. Detailed analysis of larval head capsule widths and consideration of growth ratios indicate that there are seven rather than six larval instars and that the pattern of development does not deviate significantly from that defined by the Brooks-Dyar rule. Field-rearing of larvae indicates that first-instar larvae overwinter, while field- and laboratory-rearing both indicate that larvae moult once per year, every year. These data and observations greatly shorten and simplify the life history from that previously published and suggest a life cycle of 7 rather than 14 years. This revised life cycle is not presented as an absolute, in recognition of the potential for individual variation, but rather as typical of the developmental pattern of most of the population. As such, it should provide a useful base line for further studies, especially those addressing the influence of predicted climate change in the Arctic.

Amorphous Si and Ca affect microbial community structure in arctic permafrost soils

2021 ◽  
Author(s):  
Peter Stimmler ◽  
Jörg Schaller
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
High Arctic ◽  
The Arctic ◽  
Gram Positive Bacteria ◽  
Arctic Soil ◽  
Permafrost Soils ◽  
Low Arctic ◽  
Amorphous Si

<p>Arctic warming affects the permafrost soils in different ways. Increase soil temperature and thawing of deeper horizons modifies the release of greenhouse gases (GHG) by release of nutrients. A lot of research was done about nutrient cycling of C, N and P, but little is known about the influence of Ca and amorphous Si (ASi) on this elements. To show the potential of this two elements in the Arctic systems, we analysed the effect of ASi and Ca on microbial community structure with next generation sequencing and qPCR. We analyzed fungal and bacterial community structure in two different soils from Greenland after incubation with different levels of ASi and Ca. Microbial community reacted differently in the high Arctic (Peary Land) and low Arctic soil (Disko Island) to changing concentrations of ASi and Ca. We found a significant change with linear correlation from gram-negative to gram-positive bacteria classes with increasing Ca and/or ASi levels. Further, abundance of Ascomycota and Basidiomycota changed. We postulate this changes as an important factor for changed GHG production as potential response to modified nutrient availability.</p>

scholarly journals Assessing volumetric change distributions and scaling relations of retrogressive thaw slumps across the Arctic

2021 ◽  
Author(s):  
Philipp Bernhard ◽  
Simon Zwieback ◽  
Nora Bergner ◽  
Irena Hajnsek
Keyword(s):  
Regional Differences ◽  
Scaling Laws ◽  
Remote Sensing Data ◽  
High Arctic ◽  
The Arctic ◽  
Scaling Relations ◽  
Volumetric Change ◽  
Total Size ◽  
Inverse Gamma ◽  
The Individual

Abstract. Arctic ice-rich permafrost is becoming increasingly vulnerable to terrain altering thermokarst, and among the most rapid and dramatic of these changes are retrogressive thaw slumps (RTS). They initiate when ice-rich soils are exposed and thaw, leading to the formation of a steep headwall which retreats during the summer months. These impacts, the distribution and scaling laws governing RTS changes within and between regions are unknown. Using TanDEM-X-derived digital elevation models, we estimated RTS volume and area changes over a 5-year period. We contrasted 9 regions (Eurasia: 4, North America: 5), with a total size of 220,000 km3, and over that time all 1853 RTSs combined mobilized a total volume of 17 · 106 m3 yr−1 corresponding to a volumetric change density of 77 m3 yr−1 km−2. Our remote sensing data revealed inter-regional differences in mobilized volumes, scaling laws and terrain controls. The area-to-volume scaling could be well described by a power law with an exponent of 1.15 across all regions, however the individual regions had scaling exponents ranging from 1.05 to 1.37 indicating that regional characteristics need to be taken into account when estimating RTS volumetric change from area change. The distributions of RTS area and volumetric change rates followed an inverse gamma function with a distinct peak and an exponential decrease for the largest RTSs. We found that distributions in the high Arctic were shifted towards larger values. Among the terrain controls on RTS distributions that we examined, slope, adjacency to waterbodies and aspect, the latter showed the greatest, but regionally variable association with thaw slump occurrence. Accounting for the observed regional differences in volumetric change distributions, scaling relations and terrain controls may enhance the modelling and monitoring of Arctic carbon, nutrient and sediment cycles.

scholarly journals Variation in Egg Size and Laying Date in Thick-Billed Murre Populations Breeding in the Low Arctic and High Arctic

The Condor ◽  
2005 ◽  
Vol 107 (3) ◽  
pp. 657-664 ◽  
Author(s):  
J. Mark Hipfner ◽  
Anthony J. Gaston ◽  
H. Grant Gilchrist
Keyword(s):  
Life History ◽  
Egg Size ◽  
Life History Traits ◽  
High Arctic ◽  
The Arctic ◽  
Laying Date ◽  
Uria Lomvia ◽  
Ice Conditions ◽  
Low Arctic ◽  
Historia De Vida

Abstract We used data collected across 28 years (1975–2002) to compare how timing of laying and egg size respond to environmental variability in two low-arctic and two high-arctic Thick-billed Murre (Uria lomvia) populations. Ice conditions strongly affect food availability to marine birds in the Arctic, and the percentage of the sea's surface covered by ice within 300 km of the breeding colony varied more among years near the start of laying at our high-arctic study colonies (Prince Leopold and Coburg Islands, Nunavut, Canada) than at our low-arctic study colonies (Coats and Digges Islands, Nunavut). However, mean values differed little. These results indicate that Thick-billed Murres breeding in the High Arctic experience more variable ice conditions, but not necessarily more severe ice conditions, during the period of egg formation. In response, both median laying date and mean egg size varied more among years at high-arctic than at low-arctic colonies. Several lines of evidence suggested that the variation was a result of within-female effects, i.e., phenotypic plasticity rather than different individuals breeding in years in which environmental conditions differed. Previous studies have shown that Thick-billed Murres lay eggs later in years of heavier ice coverage, especially in the High Arctic where ice conditions can be severe, and only in the High Arctic was later laying associated with reduced egg size. The relationship tended towards a negative asymptote suggesting that each female may have her own minimum egg size. Our results show that Thick-billed Murres that inhabit a more variable environment display greater variability in life-history traits. More generally, they offer insight into mechanisms linking environmental heterogeneity to phenotypic variation in life-history traits. Variación en el Tamaño del Huevo y la Fecha de Puesta en Poblaciones Reproductivas de Uria lomvia en el Ártico Bajo y el Ártico Alto Resumen. Empleamos datos colectados a lo largo de 28 años (1975–2002) para determinar cómo el ajuste temporal de la puesta y del tamaño del huevo responde a la variabilidad ambiental en dos poblaciones del Ártico bajo y dos poblaciones del Ártico alto de Uria lomvia. Las condiciones del hielo afectaron fuertemente la disponibilidad de alimentos para las aves marinas en el Ártico. El porcentaje de la superficie del mar cubierta por hielo a menos de 300 km de la colonia reproductiva varió más entre años cerca del inicio de la puesta en nuestras colonias de estudio del Ártico alto (Islas Prince Leopold y Coburg, Nunavut, Canadá) que en nuestras colonias de estudio del Ártico bajo (Islas Coats and Digges, Nunavut). Sin embargo, los valores medios difirieron poco. Estos resultados indican que los individuos de Uria lomvia que crían en el Ártico alto experimentan condiciones de hielo más variables, pero no necesariamente más severas, durante el período de la formación del huevo. Como respuesta, tanto la fecha mediana de puesta y la media del tamaño del huevo variaron más entre años en las colonias del Ártico alto que en las del Ártico bajo. Varias líneas de evidencia sugirieron que esta variación fue el resultado de variaciones propias de las hembras (i.e., plasticidad fenotípica) y no de variación entre individuos diferentes que criaron en años en los cuales las condiciones ambientales difirieron. Estudios previos han mostrado que Uria lomvia realiza su puesta más tarde en los años de mucha cobertura de hielo, especialmente en el Ártico alto, donde las condiciones de hielo pueden ser severas, y sólo en el Ártico alto la demora de la puesta se asoció con una reducción del tamaño del huevo. La relación tendió hacia una asíntota negativa, sugiriendo que cada hembra podría tener su propio tamaño mínimo del huevo. Nuestros resultados muestran que los individuos de Uria lomvia que habitan un ambiente más variable muestran mayor variabilidad en los rasgos de historia de vida. De modo más general, nuestros resultados ofrecen información sobre los mecanismos que vinculan la heterogeneidad ambiental con la variación fenotípica en los rasgos de historia de vida.

scholarly journals Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments

2019 ◽  
Vol 16 (23) ◽  
pp. 4535-4553 ◽  
Author(s):  
Caroline Coch ◽  
Bennet Juhls ◽  
Scott F. Lamoureux ◽  
Melissa J. Lafrenière ◽  
Michael Fritz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
High Arctic ◽  
The Arctic ◽  
Permafrost Degradation ◽  
Low Arctic ◽  
Arctic Rivers ◽  
Flow Pathways ◽  
Small Catchments

Abstract. Climate change is affecting the rate of carbon cycling, particularly in the Arctic. Permafrost degradation through deeper thaw and physical disturbances results in the release of carbon dioxide and methane to the atmosphere and to an increase in lateral dissolved organic matter (DOM) fluxes. Whereas riverine DOM fluxes of the large Arctic rivers are well assessed, knowledge is limited with regard to small catchments that cover more than 40 % of the Arctic drainage basin. Here, we use absorption measurements to characterize changes in DOM quantity and quality in a low Arctic (Herschel Island, Yukon, Canada) and a high Arctic (Cape Bounty, Melville Island, Nunavut, Canada) setting with regard to geographical differences, impacts of permafrost degradation, and rainfall events. We find that DOM quantity and quality is controlled by differences in vegetation cover and soil organic carbon content (SOCC). The low Arctic site has higher SOCC and greater abundance of plant material resulting in higher chromophoric dissolved organic matter (cDOM) and dissolved organic carbon (DOC) than in the high Arctic. DOC concentration and cDOM in surface waters at both sites show strong linear relationships similar to the one for the great Arctic rivers. We used the optical characteristics of DOM such as cDOM absorption, specific ultraviolet absorbance (SUVA), ultraviolet (UV) spectral slopes (S275–295), and slope ratio (SR) for assessing quality changes downstream, at base flow and storm flow conditions, and in relation to permafrost disturbance. DOM in streams at both sites demonstrated optical signatures indicative of photodegradation downstream processes, even over short distances of 2000 m. Flow pathways and the connected hydrological residence time control DOM quality. Deeper flow pathways allow the export of permafrost-derived DOM (i.e. from deeper in the active layer), whereas shallow pathways with shorter residence times lead to the export of fresh surface- and near-surface-derived DOM. Compared to the large Arctic rivers, DOM quality exported from the small catchments studied here is much fresher and therefore prone to degradation. Assessing optical properties of DOM and linking them to catchment properties will be a useful tool for understanding changing DOM fluxes and quality at a pan-Arctic scale.

scholarly journals Characterizing organic matter composition in small Low and High Arctic catchments using terrestrial colored dissolved organic matter (cDOM)

2019 ◽  
Author(s):  
Caroline Coch ◽  
Bennet Juhls ◽  
Scott F. Lamoureux ◽  
Melissa Lafrenière ◽  
Michael Fritz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
High Arctic ◽  
The Arctic ◽  
Permafrost Degradation ◽  
Low Arctic ◽  
Arctic Rivers ◽  
Flow Pathways ◽  
Small Catchments

Abstract. Climate change is an important control of carbon cycling, particularly in the Arctic. Permafrost degradation through deeper thaw and physical disturbances result in the release of carbon dioxide and methane to the atmosphere and to an increase in riverine dissolved organic matter (DOM) fluxes. Whereas riverine DOM fluxes of the large Arctic rivers are well assessed, knowledge is limited with regard to small catchments that cover more than 40 % of the Arctic drainage basin. Here, we use absorption measurements to characterize changes in DOM quantity and quality in a Low Arctic (Herschel Island, Yukon, Canada) and a High Arctic (Cape Bounty, Melville Island, Nunavut, Canada) setting with regard to geographical differences, impacts of permafrost degradation and rainfall events. We find that DOM quantity and quality is controlled by differences in vegetation cover and soil organic carbon content. The Low Arctic site has higher SOCC and greater abundance of plant material introducing higher lignin concentrations into the aquatic system and resulting in a stronger color of DOM than in the High Arctic. There is a strong relationship between dissolved organic carbon (DOC) concentration and absorption characteristics (cDOM) for surface waters at both sites similar to the one for the great Arctic rivers. We used the optical characteristics of DOM such as cDOM absorption, Specific UltraViolet Absorbance SUVA, UltraViolet UV Slope, Slope Ratio for assessing quality changes downstream, at baseflow and stormflow conditions and in relation to permafrost disturbance. DOM in streams at both sites demonstrated optical signatures indicative of photodegradation downstream processes, even over short distances of 2000 m. It was determined that flow pathways and the connected hydrological residence time control DOM quality. Deeper flow pathways allow the export of permafrost-derived DOM, whereas shallow pathways with shorter residence times lead to the export of fresh near-surface derived DOM. Compared to the large Arctic rivers, DOM quality exported from the small catchments studied here is much fresher and therefore prone to degradation. This work shows that optical properties of DOM will be a useful tool for understanding DOM sources and quality at a pan-Arctic scale.

scholarly journals Climate warming may affect the optimal timing of reproduction for migratory geese differently in the low and high Arctic

Oecologia ◽  
2019 ◽  
Vol 191 (4) ◽  
pp. 1003-1014 ◽  
Author(s):  
Thomas K. Lameris ◽  
Margje E. de Jong ◽  
Michiel P. Boom ◽  
Henk P. van der Jeugd ◽  
Konstantin E. Litvin ◽  
...  
Keyword(s):  
Climate Warming ◽  
High Arctic ◽  
Egg Laying ◽  
The Arctic ◽  
Laying Date ◽  
Optimal Timing ◽  
Negative Effects ◽  
Barnacle Goose ◽  
Timing Of Reproduction ◽  
Low Arctic

Abstract Rapid climate warming is driving organisms to advance timing of reproduction with earlier springs, but the rate of advancement shows large variation, even among populations of the same species. In this study, we investigated how the rate of advancement in timing of reproduction with a warming climate varies for barnacle goose (Branta leucopsis) populations breeding at different latitudes in the Arctic. We hypothesized that populations breeding further North are generally more time constrained and, therefore, produce clutches earlier relative to the onset of spring than southern populations. Therefore, with increasing temperatures and a progressive relief of time constraint, we expected latitudinal differences to decrease. For the years 2000–2016, we determined the onset of spring from snow cover data derived from satellite images, and compiled data on egg laying date and reproductive performance in one low-Arctic and two high-Arctic sites. As expected, high-Arctic geese laid their eggs earlier relative to snowmelt than low-Arctic geese. Contrary to expectations, advancement in laying dates was similar in high- and low-Arctic colonies, at a rate of 27% of the advance in date of snowmelt. Although advancement of egg laying did not fully compensate for the advancement of snowmelt, geese laying eggs at intermediate dates in the low Arctic were the most successful breeders. In the high Arctic, however, early nesting geese were the most successful breeders, suggesting that high-Arctic geese have not advanced their laying dates sufficiently to earlier springs. This indicates that high-Arctic geese especially are vulnerable to negative effects of climate warming.

scholarly journals Specific Features of the Macrozoobenthic Communities of Small Arctic Lakes in Eurasia

2021 ◽  
Vol 14 (4) ◽  
pp. 401-414
Author(s):  
M. V. Chertoprud ◽  
S. V. Krylenko ◽  
A. I. Lukinych ◽  
P. M. Glazov ◽  
O. P. Dubovskaya ◽  
...  
Keyword(s):  
Original Data ◽  
High Arctic ◽  
Arctic Lakes ◽  
The Arctic ◽  
Taxonomic Structure ◽  
Macroinvertebrate Communities ◽  
Total Abundance ◽  
Small Lakes ◽  
Low Arctic ◽  
Kolguev Island

Abstract The taxonomic structure, typology, species richness, and total abundance of bentic and littoral macroinvertebrate communities from small lakes of the Arctic and Subarctic zones are considered on the basis of original data from three northern Palearctic regions (the foot of the Putorana Plateau, Kolguev Island, and Western Svalbard Island). A comparative analysis of the communities of these regions has been carried out. The features of High Arctic insular, Low Arctic, subarctic, and boreal lake communities are discussed using a large volume of literature data. The complex pattern of changes in the total benthos biomass of small lakes has been revealed: it decreases in the subarctic taiga, increases in the hypoarctic tundra, and decreases again in the High Arctic.

Summer phytoplankton of the northern Barents Sea (75–80º N)

2019 ◽  
pp. 8-19
Author(s):  
Larisa A. Pautova ◽  
Vladimir A. Silkin ◽  
Marina D. Kravchishina ◽  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Weighted Average ◽  
Arctic Basin ◽  
High Arctic ◽  
Alexandrium Tamarense ◽  
Warm Water ◽  
The Arctic ◽  
Absolute Maximum ◽  
Deep Trench ◽  
Maximum Biomass

The structure of the summer planktonic communities of the Northern part of the Barents sea in the first half of August 2017 were studied. In the sea-ice melting area, the average phytoplankton biomass producing upper 50-meter layer of water reached values levels of eutrophic waters (up to 2.1 g/m3). Phytoplankton was presented by diatoms of the genera Thalassiosira and Eucampia. Maximum biomass recorded at depths of 22–52 m, the absolute maximum biomass community (5,0 g/m3) marked on the horizon of 45 m (station 5558), located at the outlet of the deep trench Franz Victoria near the West coast of the archipelago Franz Josef Land. In ice-free waters, phytoplankton abundance was low, and the weighted average biomass (8.0 mg/m3 – 123.1 mg/m3) corresponded to oligotrophic waters and lower mesotrophic waters. In the upper layers of the water population abundance was dominated by small flagellates and picoplankton from, biomass – Arctic dinoflagellates (Gymnodinium spp.) and cold Atlantic complexes (Gyrodinium lachryma, Alexandrium tamarense, Dinophysis norvegica). The proportion of Atlantic species in phytoplankton reached 75%. The representatives of warm-water Atlantic complex (Emiliania huxleyi, Rhizosolenia hebetata f. semispina, Ceratium horridum) were recorded up to 80º N, as indicators of the penetration of warm Atlantic waters into the Arctic basin. The presence of oceanic Atlantic species as warm-water and cold systems in the high Arctic indicates the strengthening of processes of “atlantificacion” in the region.

Determination of allostatic load dynamics in the assessment of adaptation in temporary workers in the Arctic

2020 ◽  
pp. 547-548
Author(s):  
O. Yu. Atkov ◽  
S. G. Gorokhova
Keyword(s):  
Body Mass Index ◽  
Glucose Level ◽  
Shift Work ◽  
Allostatic Load ◽  
The Arctic ◽  
Temporary Workers ◽  
Short Term ◽  
Short Term Adaptation ◽  
The Individual

The individual dynamics of the allostatic load index was revealed mainly due to changes in the glucose level, body mass index, which makes it applicable for assessing the short-term adaptation to the stay in the conditions of shift work

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