3. Arctic ecosystems

2021 ◽  
pp. 39-62
Author(s):  
Klaus Dodds ◽  
Jamie Woodward
Keyword(s):  
Environmental Change ◽  
Soil Depth ◽  
Nutrient Supply ◽  
The Arctic ◽  
High Latitudes ◽  
Arctic Ecosystems ◽  
Arctic Vegetation ◽  
Animal Populations ◽  
Key Characteristics ◽  
The Arctic Ocean

‘Arctic ecosystems’ highlights the treeless landscapes that fringe the Arctic Ocean, in which the diversity of plants is low, nutrient supply is limited, and soil depth is constrained by permafrost. The aim is to capture some of the key characteristics of the Arctic biome in the past and present. How do ecosystems function in the northern high latitudes? How have they responded to the recent environmental change? Arctic vegetation is grouped into twenty-one provinces based on various characteristics including relative uniformity of species and number of endemics. High fluctuation in animal populations is a key feature of the Arctic biome.

scholarly journals Diversity and biogeography of SAR11 bacteria from the Arctic Ocean

2019 ◽  
Author(s):  
Susanne Kraemer ◽  
Arthi Ramachandran ◽  
David Colatriano ◽  
Connie Lovejoy ◽  
David A. Walsh
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Adaptive Evolution ◽  
Brackish Water ◽  
Water Mass ◽  
The Arctic ◽  
High Latitudes ◽  
Bacterial Group ◽  
The Arctic Ocean ◽  
Globally Distributed

AbstractThe Arctic Ocean is relatively isolated from other oceans and consists of strongly stratified water masses with distinct histories, nutrient, temperature and salinity characteristics, therefore providing an optimal environment to investigate local adaptation. The globally distributed SAR11 bacterial group consists of multiple ecotypes that are associated with particular marine environments, yet relatively little is known about Arctic SAR11 diversity. Here, we examined SAR11 diversity using ITS analysis and metagenome-assembled genomes (MAGs). Arctic SAR11 assemblages were comprised of the S1a, S1b, S2, and S3 clades, and structured by water mass and depth. The fresher surface layer was dominated by an ecotype (S3-derived P3.2) previously associated with Arctic and brackish water. In contrast, deeper waters of Pacific origin were dominated by the P2.3 ecotype of the S2 clade, within which we identified a novel subdivision (P2.3s1) that was rare outside the Arctic Ocean. Arctic S2-derived SAR11 MAGs were restricted to high latitudes and included MAGs related to the recently defined S2b subclade, a finding consistent with bi-polar ecotypes and Arctic endemism. These results place the stratified Arctic Ocean into the SAR11 global biogeography and have identified SAR11 lineages for future investigation of adaptive evolution in the Arctic Ocean.

scholarly journals Carbon dynamics in the western Arctic Ocean: insights from full-depth carbon isotope profiles of DIC, DOC, and POC

2012 ◽  
Vol 9 (3) ◽  
pp. 1217-1224 ◽  
Author(s):  
D. R. Griffith ◽  
A. P. McNichol ◽  
L. Xu ◽  
F. A. McLaughlin ◽  
R. W. Macdonald ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Carbon Isotope ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Canada Basin ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
The Arctic Ocean

Abstract. Arctic warming is projected to continue throughout the coming century. Yet, our currently limited understanding of the Arctic Ocean carbon cycle hinders our ability to predict how changing conditions will affect local Arctic ecosystems, regional carbon budgets, and global climate. We present here the first set of concurrent, full-depth, dual-isotope profiles for dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and suspended particulate organic carbon (POCsusp) at two sites in the Canada Basin of the Arctic Ocean. The carbon isotope composition of sinking and suspended POC in the Arctic contrasts strongly with open ocean Atlantic and Pacific sites, pointing to a combination of inputs to Arctic POCsusp at depth, including surface-derived organic carbon (OC), sorbed/advected OC, and OC derived from in situ DIC fixation. The latter process appears to be particularly important at intermediate depths, where mass balance calculations suggest that OC derived from in situ DIC fixation contributes up to 22% of POCsusp. As in other oceans, surface-derived OC is still a dominant source to Arctic POCsusp. Yet, we suggest that significantly smaller vertical POC fluxes in the Canada Basin make it possible to see evidence of DIC fixation in the POCsusp pool even at the bulk isotope level.

scholarly journals Carbon dynamics in the western Arctic Ocean: insights from full-depth carbon isotope profiles of DIC, DOC, and POC

2011 ◽  
Vol 8 (5) ◽  
pp. 10677-10696
Author(s):  
D. R. Griffith ◽  
A. P. McNichol ◽  
L. Xu ◽  
F. A. McLaughlin ◽  
R. W. Macdonald ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Carbon Isotope ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Canada Basin ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
The Arctic Ocean

Abstract. Arctic warming is projected to continue throughout the coming century. Yet, our currently limited understanding of the Arctic Ocean carbon cycle hinders our ability to predict how changing conditions will affect local Arctic ecosystems, regional carbon budgets, and global climate. We present here the first set of concurrent, full-depth, dual-isotope profiles for dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and suspended particulate organic carbon (POCsusp) at two sites in the Canada Basin of the Arctic Ocean. The carbon isotope composition of sinking and suspended POC in the Arctic contrasts strongly with open ocean Atlantic and Pacific sites, pointing to a combination of inputs to Arctic POCsusp at depth, including surface-derived organic carbon (OC), sorbed/advected OC, and OC derived from in situ DIC fixation. The latter process appears to be particularly important at intermediate depths, where mass balance results suggest that OC derived from in situ DIC fixation contributes up to 22% of POCsusp. As in other oceans, surface-derived OC is still a dominant source to Arctic POCsusp. Yet, we suggest that significantly smaller vertical POC fluxes in the Canada Basin make it possible to see evidence of DIC fixation in the POCsusp pool even at the bulk isotope level.

scholarly journals Dispersal limitation and climate-related environmental gradients structure microcrustacean composition in freshwater lakes, Ellesmere Island, Canada

2008 ◽  
Vol 65 (9) ◽  
pp. 1905-1918 ◽  
Author(s):  
Angela L. Strecker ◽  
Rebecca Milne ◽  
Shelley E. Arnott
Keyword(s):  
Species Richness ◽  
Environmental Change ◽  
Community Composition ◽  
Environmental Gradients ◽  
Negative Relationship ◽  
Ellesmere Island ◽  
Arctic Lakes ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Daphnia Middendorffiana

Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra , Tachidius discipes , and Artemeopsis stefanssoni . Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, and conductivity and negatively affected by elevation. In contrast to most findings in temperate systems, we detected a negative relationship between species richness and surface area. Community composition was influenced by DOC, nutrients, and elevation but was also related to spatial variables, suggesting that spatial gradients in environmental conditions and dispersal are important drivers of differences among sites. Arctic ecosystems are expected to change rapidly in the coming years because of climate change and ozone thinning, and we expect that associated changes in DOC, temperature, and nutrients will affect microcrustacean species richness and distribution throughout the landscape.

IP25 AND BRASSICASTEROL: THE BIOMARKER AS ICE PROXY FOR THE SEA ICE COVERING IN THE ARCTIC OCEAN

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Adelina Manurung
Keyword(s):  
Sea Ice ◽  
The Arctic ◽  
High Latitudes ◽  
Major Focus ◽  
Secondary Importance ◽  
Degradation Processes ◽  
East Siberian Sea ◽  
The Arctic Ocean ◽  
The Stability ◽  
And Storage

Stable biomolecules play an important role in the oceans because they can be used to determine the origin and the translocation of the organic material such as sterols which are synthesized by plants. In recent times, a major focus has been on a new biomarker in the high latitudes, a highly branched Isoprenoid (HBI) as the new sea ice proxy 2,6,10,14-tetramethyl-7-(3-methylpent-4-enyl) Pentadecane (IP25, Ice Proxy with 25 carbon atoms). The stability of the proxies such as sterols and HBI is important because only an almost inert character of the molecules ensures its reproducible use as biomarker proxy.In this research, different analytical methods were used to check whether these components actually fulfill the requirements of duration and storage to be stable that possible degradation processes such as microbial degradation and autoxidation. However, duration and storage are proven negligible or can be treated as the secondary essential factors. For this purpose, samples of a sediment core from the continental shelf of the East Siberian Sea were analyzed. Samples from this core were stored (1) deep frozen directly after sampling (-30°C) and (2) at 5°C for an extended time period.The results show that the degradation processes are negligible or least only of secondary importance. The concentrations of the biomarker show good correlations. The ratio between Brassicasterol and IP25 (PIP25-Index) is not affected by the different storages. In addition, all measurements using gas chromatography and mass spectrometry result in nearly the same concentrations of the compounds. 

scholarly journals Nutrient pathways and their susceptibility to past and future change in the Eurasian Arctic Ocean

AMBIO ◽  
2021 ◽  
Author(s):  
Robyn E. Tuerena ◽  
Claire Mahaffey ◽  
Sian F. Henley ◽  
Camille de la Vega ◽  
Louisa Norman ◽  
...  
Keyword(s):  
Primary Production ◽  
Arctic Ocean ◽  
Nutrient Dynamics ◽  
Barents Sea ◽  
Nitrogen Loss ◽  
Standing Stock ◽  
Research Priorities ◽  
Nutrient Supply ◽  
The Arctic ◽  
Arctic Ecosystems

AbstractClimate change is altering nutrient cycling within the Arctic Ocean, having knock-on effects to Arctic ecosystems. Primary production in the Arctic is principally nitrogen-limited, particularly in the western Pacific-dominated regions where denitrification exacerbates nitrogen loss. The nutrient status of the eastern Eurasian Arctic remains under debate. In the Barents Sea, primary production has increased by 88% since 1998. To support this rapid increase in productivity, either the standing stock of nutrients has been depleted, or the external nutrient supply has increased. Atlantic water inflow, enhanced mixing, benthic nitrogen cycling, and land–ocean interaction have the potential to alter the nutrient supply through addition, dilution or removal. Here we use new datasets from the Changing Arctic Ocean program alongside historical datasets to assess how nitrate and phosphate concentrations may be changing in response to these processes. We highlight how nutrient dynamics may continue to change, why this is important for regional and international policy-making and suggest relevant research priorities for the future.

Workshop on biodiversity and functioning of arctic ecosystems — continuing work on the «Arctic Vegetation Archive» (Arkhangelsk, 21–23 May 2019)

2019 ◽  
pp. 85-90
Author(s):  
K. V. Ivanova ◽  
A. M. Lapina ◽  
D. D. Karsonova
Keyword(s):  
International Communication ◽  
The Arctic ◽  
Breakout Session ◽  
Arctic Ecosystems ◽  
Arctic Vegetation ◽  
National Archives ◽  
Working Groups ◽  
To Come ◽  
International Archive

The three-days Arctic Vegetation Archive and Classification Workshop, in which 32 participants from 9 countries (Canada, Finland, Germany, Italy, Norway, Republic of Slovakia, Russia, Switzerland, USA) participated, took place at the Northern Arctic Federal University, Arkhangelsk, Russia on 21–23 May 2019. The participants reviewed success in archiving data into the AVA and regional Archives, which has been achieved in the last 2 years. International Archive already contains large number of datasets, which allowed to define the ways to use this data for the assessment the dynamic of vegetation due to climate change. Discussion was also focused on the results of regional classification with an attempt to come up with a common approach. During the breakout session, attention was brought to the necessity of international communication: everyone agreed that developing a network will make cooperation easier. At the end of the meeting on 23 May the participants stated long-term goals for the next 4 years: Integrate Russian data entries into AVA by Komarov Botanical Institute and A. N. Severtsov Institute working groups; Develop standardized methods for surveys, archiving and classification; Establish the system of databases management and rules for sharing data; Create a central website containing basic information about national Archives, georeferences and links; Establish funding to complete AVA, AVC and the website. Next meeting will take place at Arctic Science Summit Week in Portugal 2021.

scholarly journals Essai: Is Arctic Palynology a “Blunt Instrument”?

2007 ◽  
Vol 60 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Konrad Gajewski
Keyword(s):  
Environmental Change ◽  
Spatial Resolution ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Temporal And Spatial ◽  
Pollen Analyses ◽  
The Way

AbstractFor nearly forty years, palynologists and other scientists studying the Quaternary have claimed that palynology, when applied in the Arctic, is a “blunt instrument” for analysing environmental change in this region. In this essay, the author explains why this expression should be laid to rest. Limits to palynological resolution are spatial, temporal and taxonomic. These are discussed and examples are shown where both the temporal and spatial resolution of pollen analyses is far higher than previously thought possible. The supposed “bluntness” of Arctic palynology is due to the way this tool has been applied in Arctic environments rather than inherent limits of palynology in Arctic ecosystems.

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