Minimal Evidence of Permafrost Carbon in Siberia’s Kolyma River

Abstract. Lakes in permafrost regions are dynamic landscape components and play an important role for climate change feedbacks. Lake processes such as mineralization and flocculation of dissolved organic carbon (DOC), one of the main carbon fractions in lakes, contribute to the greenhouse effect and are part of the global carbon cycle. These processes are in the focus of climate research, but studies so far are limited to specific study regions. In our synthesis, we analyzed 2167 water samples from 1833 lakes across the Arctic in permafrost regions of Alaska, Canada, Greenland, and Siberia to provide first pan-Arctic insights for linkages between DOC concentrations and the environment. Using published data and unpublished datasets from the author team, we report regional DOC differences linked to latitude, permafrost zones, ecoregions, geology, near-surface soil organic carbon contents, and ground ice classification of each lake region. The lake DOC concentrations in our dataset range from 0 to 1130 mg L−1 (10.8 mg L−1 median DOC concentration). Regarding the permafrost regions of our synthesis, we found median lake DOC concentrations of 12.4 mg L−1 (Siberia), 12.3 mg L−1 (Alaska), 10.3 mg L−1 (Greenland), and 4.5 mg L−1 (Canada). Our synthesis shows a significant relationship between lake DOC concentration and lake ecoregion. We found higher lake DOC concentrations at boreal permafrost sites compared to tundra sites. We found significantly higher DOC concentrations in lakes in regions with ice-rich syngenetic permafrost deposits (yedoma) compared to non-yedoma lakes and a weak but significant relationship between soil organic carbon content and lake DOC concentration as well as between ground ice content and lake DOC. Our pan-Arctic dataset shows that the DOC concentration of a lake depends on its environmental properties, especially on permafrost extent and ecoregion, as well as vegetation, which is the most important driver of lake DOC in this study. This new dataset will be fundamental to quantify a pan-Arctic lake DOC pool for estimations of the impact of lake DOC on the global carbon cycle and climate change.

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Climate change effects on peatland decomposition and porewater dissolved organic carbon biogeochemistry

Biogeochemistry ◽

10.1007/s10533-016-0214-8 ◽

2016 ◽

Vol 128 (3) ◽

pp. 385-396 ◽

Cited By ~ 18

Author(s):

Catherine M. Dieleman ◽

Zoë Lindo ◽

James W. McLaughlin ◽

Aaron E. Craig ◽

Brian A. Branfireun

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Climate Change Effects ◽

Carbon Biogeochemistry

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Characterization of bacterioplankton communities and quantification of organic carbon pools off the Galapagos Archipelago under contrasting environmental conditions

PeerJ ◽

10.7717/peerj.5984 ◽

2018 ◽

Vol 6 ◽

pp. e5984 ◽

Cited By ~ 4

Author(s):

Nataly Carolina Guevara Campoverde ◽

Christiane Hassenrück ◽

Pier Luigi Buttigieg ◽

Astrid Gärdes

Keyword(s):

Organic Carbon ◽

Carbon Cycle ◽

Dissolved Organic Carbon ◽

Bacterial Communities ◽

Carbon Pools ◽

Aggregate Formation ◽

Galapagos Archipelago ◽

Carbon Concentrations ◽

Bacterioplankton Communities

Bacteria play a crucial role in the marine carbon cycle, contributing to the production and degradation of organic carbon. Here, we investigated organic carbon pools, aggregate formation, and bacterioplankton communities in three contrasting oceanographic settings in the Galapagos Archipelago. We studied a submarine CO2 vent at Roca Redonda (RoR), an upwelling site at Bolivar Channel (BoC) subjected to a weak El Niño event at the time of sampling in October 2014, as well as a site without volcanic or upwelling influence at Cowley Islet (CoI). We recorded physico-chemical parameters, and quantified particulate and dissolved organic carbon, transparent exopolymeric particles, and the potential of the water to form larger marine aggregates. Free-living and particle-attached bacterial communities were assessed via 16S rRNA gene sequencing. Both RoR and BoC exhibited temperatures elevated by 1–1.5 °C compared to CoI. RoR further experienced reduced pH between 6.8 and 7.4. We observed pronounced differences in organic carbon pools at each of the three sites, with highest dissolved organic carbon concentrations at BoC and RoR, and highest particulate organic carbon concentrations and aggregate formation at BoC. Bacterioplankton communities at BoC were dominated by opportunistic copiotrophic taxa, such as Alteromonas and Roseobacter, known to thrive in phytoplankton blooms, as opposed to oligotrophic taxa dominating at CoI, such as members of the SAR11 clade. Therefore, we propose that bacterial communities were mainly influenced by the availability of organic carbon at the investigated sites. Our study provides a comprehensive characterization of organic carbon pools and bacterioplankton communities, highlighting the high heterogeneity of various components of the marine carbon cycle around the Galapagos Archipelago.

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Climate Change Impacts on the Organic Carbon Cycle at the Land-Ocean Interface

Annual Review of Earth and Planetary Sciences ◽

10.1146/annurev-earth-042711-105511 ◽

2012 ◽

Vol 40 (1) ◽

pp. 685-711 ◽

Cited By ~ 60

Author(s):

Elizabeth A. Canuel ◽

Sarah S. Cammer ◽

Hadley A. McIntosh ◽

Christina R. Pondell

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Carbon Cycle ◽

Climate Change Impacts

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Assessment of potential climate change impacts on peatland dissolved organic carbon release and drinking water treatment from laboratory experiments

Environmental Pollution ◽

10.1016/j.envpol.2012.09.022 ◽

2013 ◽

Vol 173 ◽

pp. 270-277 ◽

Cited By ~ 24

Author(s):

R. Tang ◽

J.M. Clark ◽

T. Bond ◽

N. Graham ◽

D. Hughes ◽

...

Keyword(s):

Climate Change ◽

Drinking Water ◽

Water Treatment ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Laboratory Experiments ◽

Drinking Water Treatment ◽

Climate Change Impacts ◽

Carbon Release ◽

Potential Climate Change

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Globally Carbon Cycle and Measurement of Dissolved Organic Carbon in Sea Water.

Journal of Environmental Chemistry ◽

10.5985/jec.4.1 ◽

1994 ◽

Vol 4 (1) ◽

pp. 1-18

Author(s):

Yoshimi SUZUKI ◽

Hiroshi ITO

Keyword(s):

Organic Carbon ◽

Carbon Cycle ◽

Dissolved Organic Carbon ◽

Sea Water

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Global soil organic carbon removal by water erosion under climate change and land use change during 1850–2005 AD

10.5194/bg-2017-527 ◽

2018 ◽

Author(s):

Victoria Naipal ◽

Philippe Ciais ◽

Yilong Wang ◽

Ronny Lauerwald ◽

Bertrand Guenet ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Soil Erosion ◽

Organic Carbon ◽

Land Use Change ◽

Soil Organic Carbon ◽

Climate Variability ◽

Carbon Cycle ◽

Atmospheric Co2 ◽

Terrestrial Carbon

Abstract. The onset and expansion of agriculture has accelerated soil erosion by rainfall and runoff substantially, mobilizing vast quantities of soil organic carbon (SOC) globally. Studies show that at timescales of decennia to millennia this mobilized SOC can significantly alter previously estimated carbon emissions from land use change (LUC). However, a full understanding of the impact of erosion on land-atmosphere carbon exchange is still missing. The aim of our study is to better constrain the terrestrial carbon fluxes by developing methods compatible with Earth System Models (ESMs) in order to explicitly represent the links between soil erosion by rainfall and runoff and carbon dynamics. For this we use an emulator that represents the carbon cycle of a land surface model, in combination with the Revised Universal Soil Loss Equation model. We applied this modeling framework at the global scale to evaluate the effects of potential soil erosion (soil removal only) in the presence of other perturbations of the carbon cycle: elevated atmospheric CO2, climate variability, and LUC. We found that over the period 1850–2005 AD acceleration of soil erosion leads to a total potential SOC removal flux of 100 Pg C of which 80 % occurs on agricultural, pasture and natural grass lands. Including soil erosion in the SOC-dynamics scheme results in a doubling of the cumulative loss of SOC over 1850–2005 due to the combined effects of climate variability, increasing atmospheric CO2 and LUC. This additional erosional loss decreases the cumulative global carbon sink on land by 5 Pg for this specific period, with the largest effects found for the tropics, where deforestation and agricultural expansion increased soil erosion rates significantly. We also show that the potential effects of soil erosion on the global SOC stocks cannot be ignored when compared to the effects of climate change or land use change on the carbon cycle. We conclude that it is necessary to include soil erosion in assessments of LUC and evaluations of the terrestrial carbon cycle.

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Hydrological controls on DOC : nitrate resource stoichiometry in a lowland, agricultural catchment, southern UK

10.5194/hess-2017-30 ◽

2017 ◽

Cited By ~ 2

Author(s):

Catherine M. Heppell ◽

Andrew Binley ◽

Mark Trimmer ◽

Tegan Darch ◽

Ashley Jones ◽

...

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

River Water ◽

Positive Relationship ◽

Agricultural Landscapes ◽

Lowland River ◽

Significant Positive Relationship ◽

Molar Ratios ◽

The Relationship

Abstract. The role that hydrology plays in governing the interactions between dissolved organic carbon (DOC) and nitrogen in rivers draining lowland, agricultural landscapes is currently poorly understood, yet important to assess given the potential changes to production and delivery of DOC and nitrate arising from climate change. We measured DOC and nitrate concentrations in river water of six reaches of the lowland River Hampshire Avon (Wiltshire, southern UK) in order to quantify the relationship between Baseflow Index (BFI) and DOC : nitrate molar ratios across contrasting geologies (Chalk, Greensand and clay). We found a significant positive relationship between nitrate and Baseflow Index (p

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