Traces of sunlight in carbon biochemistry of shallow subarctic lakes

2020 ◽  
Author(s):  
Marttiina Rantala ◽  
Henriikka Kivilä ◽  
Carsten Meyer-Jacob ◽  
Maxime Wauthy ◽  
Milla Rautio ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Time Scales ◽  
Carbon Pools ◽  
Uv Spectrum ◽  
Subarctic Lakes ◽  
Climate Fluctuations ◽  
Underwater Light ◽  
Long Time ◽  
Experimental Treatments

<p>Sunlight fuels the drawdown and evasion of carbon in shallow northern lakes. Amplified polar warming is altering the sunlit transport and transformation of aquatic carbon at an alarming rate entailing potential for climate feedbacks. We combined experimental and retrospective approaches to explore the synoptic interlinks between underwater light, aquatic carbon biochemistry, landscape carbon cycling and climate change in two shallow subarctic lakes with divergent light and carbon regime (a clear lake low in organic carbon and a dark organic rich lake). In situ enclosures (treatments under full sunlight, sunlight without the ultraviolet [UV] spectrum, no light) were first deployed on the lakes to decipher the effect of photochemical alteration on the spectral, elemental and isotopic properties of lake water organic carbon pools under short term (four weeks) exposure. We then focused on elemental, isotopic and spectral fingerprints archived in the sediments of the lakes to trace coeval variability in aquatic primary production, terrestrial carbon transport, and underwater light under centennial climate fluctuations. We observed distinct differences in carbon biochemistry between the experimental treatments illustrating the importance of sunlight, and particularly the UV spectrum, in shaping the carbon pools of the lakes already over short time scales. Over the past centennia, sediment biogeochemical composition carried signatures of change in carbon origins (algal vs terrestrial) and shifting underwater light regime. The results shed light on how climate change and sunlight shape carbon flows in shallow northern lakes over short and long time scales.</p>

scholarly journals Total organic carbon sensitivity to climate change from Lake Qinghai sediments at different time scales

2019 ◽  
Vol 31 (5) ◽  
pp. 1468-1478
Author(s):  
ZHANG Yao ◽  
◽  
WU Duo ◽  
ZHANG Huan ◽  
ZHOU Aifeng ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Time Scales ◽  
Lake Qinghai ◽  
Different Time Scales

scholarly journals Publishing trends on climate change vulnerability in the conservation literature reveal a predominant focus on direct impacts and long time-scales

2014 ◽  
Vol 20 (10) ◽  
pp. 1221-1228 ◽  
Author(s):  
Sarah Chapman ◽  
Karen Mustin ◽  
Anna R. Renwick ◽  
Daniel B. Segan ◽  
David G. Hole ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Climate Change Vulnerability ◽  
Long Time

scholarly journals Develop Agricultural Strategies to Increase Soil Carbon Sequestration and Reducing Greenhouse Gases Emission (Desenvolvimento de Estratégias Agrícolas para Aumentar o Sequestro de Carbono e Reduzir Emissões de Gases de Efeito Estufa)

2012 ◽  
Vol 4 (6) ◽  
pp. 1222
Author(s):  
John Kimble
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Time Increase ◽  
Forestry Practices ◽  
The World ◽  
Long Time ◽  
Per Se ◽  
Reduce Emissions

O solo é uma dos nossos mais importantes recursos naturais.  Melhor manejo dos nossos solos pode aumentar o carbono orgânico e melhorar o ambiente de modo geral. Mudanças nas práticas agrícolas/florestais podem reduzir as emissões.  Muitas além de reduzir emissões aumentam a matéria orgânica do solo. Essas práticas agrícolas/florestais têm sido estudadas por um longo período de tempo  e vem sendo usadas em muitas áreas no mundo, mas elas não tem sido aceitas ou usadas na extensão necessária. O que é preciso são estratégias que levem a adoção de práticas que resultem em sequestro de carbono orgânico no solo e reduzam a emissão de GEE. Estratégias não são as práticas per se, mas as políticas de incentivo e penalização que as implementam. Devem ser desenvolvidas estratégias que superem as resistências a mudanças nas práticas agrícolas/florestais para aqueles que trabalham na terra. Essas estratégias não podem ser desenvolvidas sem a participação d e fazendeiros e florestais. Elas devem permitir lucratividade como parte da equação e devem ser ambientalmente amigáveis. Palavras - chave: mitigação, mudanças climáticas.  Desenvolvimento de Estratégias Agrícolas para Aumentar o Sequestro de Carbono e Reduzir Emissões de Gases de Efeito Estufa  ABSTRACTSoils are one of our most important resources.  Better management of our soils can increase Soil Organic Carbon (SOC) and improve the overall environment.  Changing farming/ forestry practices can reduce emissions.  Many practices will reduce emissions and at the same time increase SOC.  These farming/forestry practices have been studied for a long time and are being used in many areas of the world but they have not been accepted and or used to the necessary extent.  What is needed are strategies that will lead to the adoption of practices that lead to SOC sequestration and a reduction of GHG’s.  Strategies are not the practices per se but the policies and or carrot and sticks that get the known practices on the ground.  Strategies need to be developed that overcome the resistance to changes in farming/forestry practices for the ones doing the work on the ground.  Strategies cannot be developed without input from the farmers/foresters.  These strategies need to allow profitability as part of the equation and they need to be environmentally friendly.Keywords: mitigation, climate change 

scholarly journals Climate change increases riverine carbon outgassing, while export to the ocean remains uncertain

2016 ◽  
Vol 7 (3) ◽  
pp. 559-582 ◽  
Author(s):  
F. Langerwisch ◽  
A. Walz ◽  
A. Rammig ◽  
B. Tietjen ◽  
K. Thonicke ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Atlantic Ocean ◽  
Organic Material ◽  
Large Scale ◽  
Amazon Basin ◽  
Carbon Budget ◽  
Carbon Pools ◽  
Carbon Budgets ◽  
Sres Scenario

Abstract. Any regular interaction of land and river during flooding affects carbon pools within the terrestrial system, riverine carbon and carbon exported from the system. In the Amazon basin carbon fluxes are considerably influenced by annual flooding, during which terrigenous organic material is imported to the river. The Amazon basin therefore represents an excellent example of a tightly coupled terrestrial–riverine system. The processes of generation, conversion and transport of organic carbon in such a coupled terrigenous–riverine system strongly interact and are climate-sensitive, yet their functioning is rarely considered in Earth system models and their response to climate change is still largely unknown. To quantify regional and global carbon budgets and climate change effects on carbon pools and carbon fluxes, it is important to account for the coupling between the land, the river, the ocean and the atmosphere. We developed the RIVerine Carbon Model (RivCM), which is directly coupled to the well-established dynamic vegetation and hydrology model LPJmL, in order to account for this large-scale coupling. We evaluate RivCM with observational data and show that some of the values are reproduced quite well by the model, while we see large deviations for other variables. This is mainly caused by some simplifications we assumed. Our evaluation shows that it is possible to reproduce large-scale carbon transport across a river system but that this involves large uncertainties. Acknowledging these uncertainties, we estimate the potential changes in riverine carbon by applying RivCM for climate forcing from five climate models and three CO2 emission scenarios (Special Report on Emissions Scenarios, SRES). We find that climate change causes a doubling of riverine organic carbon in the southern and western basin while reducing it by 20 % in the eastern and northern parts. In contrast, the amount of riverine inorganic carbon shows a 2- to 3-fold increase in the entire basin, independent of the SRES scenario. The export of carbon to the atmosphere increases as well, with an average of about 30 %. In contrast, changes in future export of organic carbon to the Atlantic Ocean depend on the SRES scenario and are projected to either decrease by about 8.9 % (SRES A1B) or increase by about 9.1 % (SRES A2). Such changes in the terrigenous–riverine system could have local and regional impacts on the carbon budget of the whole Amazon basin and parts of the Atlantic Ocean. Changes in riverine carbon could lead to a shift in the riverine nutrient supply and pH, while changes in the exported carbon to the ocean lead to changes in the supply of organic material that acts as a food source in the Atlantic. On larger scales the increased outgassing of CO2 could turn the Amazon basin from a sink of carbon to a considerable source. Therefore, we propose that the coupling of terrestrial and riverine carbon budgets should be included in subsequent analysis of the future regional carbon budget.

scholarly journals Climate change effects on the stability and chemistry of soil organic carbon pools in a subalpine grassland

2017 ◽  
Vol 132 (1-2) ◽  
pp. 123-139 ◽  
Author(s):  
Jérémy Puissant ◽  
Robert T. E. Mills ◽  
Bjorn J. M. Robroek ◽  
Konstantin Gavazov ◽  
Yves Perrette ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Pools ◽  
Climate Change Effects ◽  
Soil Organic Carbon Pools ◽  
The Stability

scholarly journals Orbital forcing of climate 1.4 billion years ago

2015 ◽  
Vol 112 (12) ◽  
pp. E1406-E1413 ◽  
Author(s):  
Shuichang Zhang ◽  
Xiaomei Wang ◽  
Emma U. Hammarlund ◽  
Huajian Wang ◽  
M. Mafalda Costa ◽  
...  
Keyword(s):  
Time Scales ◽  
Ocean Circulation ◽  
Climate Fluctuations ◽  
The North ◽  
Organic Carbon Flux ◽  
Stratigraphic Framework ◽  
Long Time ◽  
Detrital Particles ◽  
Xiamaling Formation

Fluctuating climate is a hallmark of Earth. As one transcends deep into Earth time, however, both the evidence for and the causes of climate change become difficult to establish. We report geochemical and sedimentological evidence for repeated, short-term climate fluctuations from the exceptionally well-preserved ∼1.4-billion-year-old Xiamaling Formation of the North China Craton. We observe two patterns of climate fluctuations: On long time scales, over what amounts to tens of millions of years, sediments of the Xiamaling Formation record changes in geochemistry consistent with long-term changes in the location of the Xiamaling relative to the position of the Intertropical Convergence Zone. On shorter time scales, and within a precisely calibrated stratigraphic framework, cyclicity in sediment geochemical dynamics is consistent with orbital control. In particular, sediment geochemical fluctuations reflect what appear to be orbitally forced changes in wind patterns and ocean circulation as they influenced rates of organic carbon flux, trace metal accumulation, and the source of detrital particles to the sediment.

scholarly journals Climate change increases riverine carbon outgassing while export to the ocean remains uncertain

2015 ◽  
Vol 6 (2) ◽  
pp. 1445-1497 ◽  
Author(s):  
F. Langerwisch ◽  
A. Walz ◽  
A. Rammig ◽  
B. Tietjen ◽  
K. Thonicke ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Atlantic Ocean ◽  
Organic Material ◽  
Amazon Basin ◽  
Carbon Budget ◽  
Climate Models ◽  
Carbon Fluxes ◽  
Carbon Pools ◽  
Sres Scenario

Abstract. Carbon fluxes in the Amazon Basin are considerably influenced by annual flooding during which terrigenous organic material is imported to the river. This regular interaction affects carbon pools within the riverine system, terrestrial carbon, and carbon exported to the ocean and released to the atmosphere. The processes of generation, conversion, and transport of organic carbon in this coupled terrigenous–riverine system strongly interact and are climate-sensitive, yet their response to climate change is still largely unknown. To quantify climate change effects on carbon pools and on carbon fluxes within the river and to the ocean and the atmosphere, we developed the riverine carbon model RivCM, which is directly coupled to the well-established dynamic vegetation and hydrology model LPJmL. We show here that RivCM successfully reproduces observed values in exported carbon and riverine carbon concentration. We evaluate future changes in riverine carbon by applying RivCM for climate forcing from five climate models and three CO2 emission scenarios (SRES). We find that climate change causes a doubling of riverine organic carbon in the Southern and Western basin while reducing it by 20 % in the eastern and northern parts. In contrast, the amount of riverine inorganic carbon shows a 2- to 3-fold increase in the entire basin, independent of the SRES scenario. The export of carbon to the atmosphere increases as well with an average of about 30 %. In contrast, changes in future export of organic carbon to the Atlantic Ocean depend on the SRES scenario and are projected to either decrease by about 8.9 % (SRES A1B) or increase by about 9.1 % (SRES A2). Such changes in the terrigenous–riverine system could have local and regional impacts on the carbon budget of the whole Amazon Basin and parts of the Atlantic Ocean. Changes in the riverine carbon could lead to a shift in the riverine nutrient supply and pH, while changes in the exported carbon to the ocean leads to changes in the supply of organic material that acts as food source in the Atlantic. On the larger scale the increased outgassing of CO2 could turn the Amazon Basin from a sink of carbon to a considerable source. Therefore we propose that the coupling of terrestrial and riverine carbon budget should be included in subsequent analysis of the future regional carbon budget.

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