scholarly journals Sequestration of macroalgal carbon: the elephant in the Blue Carbon room

2018 ◽  
Vol 14 (6) ◽  
pp. 20180236 ◽  
Author(s):  
Dorte Krause-Jensen ◽  
Paul Lavery ◽  
Oscar Serrano ◽  
Núria Marbà ◽  
Pere Masque ◽  
...  
Keyword(s):  
Paradigm Shift ◽  
Carbon Sink ◽  
Blue Carbon ◽  
Coastal Habitats ◽  
Management Actions ◽  
Carbon Burial

Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) tracing it back to source habitats, and (iii) showing that management actions at the habitat lead to increased sequestration at the sink site. These challenges apply equally to carbon exported from BC coastal habitats. Because of the large carbon sink they support, incorporation of macroalgae into BC accounting and actions is an imperative. This requires a paradigm shift in accounting procedures as well as developing methods to enable the capacity to trace carbon from donor to sink habitats in the ocean.

scholarly journals Phosphorus supply affects long-term carbon accumulation in mid-latitude ombrotrophic peatlands

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Daniel N. Schillereff ◽  
Richard C. Chiverrell ◽  
Jenny K. Sjöström ◽  
Malin E. Kylander ◽  
John F. Boyle ◽  
...  
Keyword(s):  
Carbon Sink ◽  
Threshold Effect ◽  
Carbon Accumulation ◽  
Ecosystem Productivity ◽  
Microbial Decomposition ◽  
Nutrient Deposition ◽  
Carbon Burial ◽  
Carbon Store ◽  
Post Industrial

AbstractOmbrotrophic peatlands are a globally important carbon store and depend on atmospheric nutrient deposition to balance ecosystem productivity and microbial decomposition. Human activities have increased atmospheric nutrient fluxes, but the impacts of variability in phosphorus supply on carbon sequestration in ombrotrophic peatlands are unclear. Here, we synthesise phosphorus, nitrogen and carbon stoichiometric data in the surface and deeper layers of mid-latitude Sphagnum-dominated peatlands across Europe, North America and Chile. We find that long-term elevated phosphorus deposition and accumulation strongly correlate with increased organic matter decomposition and lower carbon accumulation in the catotelm. This contrasts with literature that finds short-term increases in phosphorus supply stimulates rapid carbon accumulation, suggesting phosphorus deposition imposes a threshold effect on net ecosystem productivity and carbon burial. We suggest phosphorus supply is an important, but overlooked, factor governing long-term carbon storage in ombrotrophic peatlands, raising the prospect that post-industrial phosphorus deposition may degrade this carbon sink.

scholarly journals Relevance of carbon burial and storage in two contrasting blue carbon ecosystems of a north-east Pacific coastal lagoon

2019 ◽  
Vol 675 ◽  
pp. 581-593 ◽  
Author(s):  
Tomasa Cuellar-Martinez ◽  
Ana Carolina Ruiz-Fernández ◽  
Joan-Albert Sanchez-Cabeza ◽  
Libia-Hascibe Pérez-Bernal ◽  
Jose Sandoval-Gil
Keyword(s):  
Coastal Lagoon ◽  
Blue Carbon ◽  
North East ◽  
East Pacific ◽  
Carbon Burial ◽  
And Storage

scholarly journals Beyond burial: lateral exchange is a significant atmospheric carbon sink in mangrove forests

2018 ◽  
Vol 14 (7) ◽  
pp. 20180200 ◽  
Author(s):  
Damien T. Maher ◽  
Mitchell Call ◽  
Isaac R. Santos ◽  
Christian J. Sanders
Keyword(s):  
Organic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Carbon Sink ◽  
Blue Carbon ◽  
Mangrove Forests ◽  
Carbon Framework ◽  
Sequestration Potential ◽  
Seagrass Ecosystems ◽  
Atmospheric Carbon

The blue carbon paradigm has evolved in recognition of the high carbon storage and sequestration potential of mangrove, saltmarsh and seagrass ecosystems. However, fluxes of the potent greenhouse gases CH 4 and N 2 O, and lateral export of carbon are often overlooked within the blue carbon framework. Here, we show that the export of dissolved inorganic carbon (DIC) and alkalinity is approximately 1.7 times higher than burial as a long-term carbon sink in a subtropical mangrove system. Fluxes of methane offset burial by approximately 6%, while the nitrous oxide sink was approximately 0.5% of burial. Export of dissolved organic carbon and particulate organic carbon to the coastal zone is also significant and combined may account for an atmospheric carbon sink similar to burial. Our results indicate that the export of DIC and alkalinity results in a long-term atmospheric carbon sink and should be incorporated into the blue carbon paradigm when assessing the role of these habitats in sequestering carbon and mitigating climate change.

scholarly journals Riverine carbon export in the arid-semiarid Wuding River catchment on the Chinese Loess Plateau

2018 ◽  
Author(s):  
Lishan Ran ◽  
Mingyang Tian ◽  
Nufang Fang ◽  
Suiji Wang ◽  
Xixi Lu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Carbon Sink ◽  
Terrestrial Ecosystems ◽  
Chinese Loess Plateau ◽  
Spatial And Temporal Variability ◽  
Wet Season ◽  
Carbon Export ◽  
Chinese Loess ◽  
Carbon Burial ◽  
The Chinese Loess Plateau

Abstract. Riverine export of terrestrially-derived carbon represent a key component of the global carbon cycle. In this study we quantify the redistribution of riverine carbon within the Wuding catchment on the Chinese Loess Plateau. Export of dissolved organic and inorganic carbon (DOC and DIC) exhibited pronounced spatial and temporal variability. While the DOC concentration was spatially comparable within the catchment, it was generally higher in spring and summer than in autumn, especially in the loess subcatchment. This reflects the enhanced organic matter inputs from agricultural tillage in spring and from terrestrial ecosystems in summer. DIC concentration in the loess subcatchment is significantly higher than that in the sandy subcatchment, due largely to dissolution of carbonates that are abundant in loess. In addition, content of particulate organic carbon (POC) shown strong seasonal variability with low values in the wet season owing to input of subsurface soils by gully erosion. The downstream carbon flux was (7±1.9)×1010 g C year−1 and dominated by DIC and POC. Total CO2 emissions from water surface were (3.7±0.5)×1010 g C year−1. Radiocarbon analysis revealed that the degassed CO2 was 810–1890 years old, indicating the release of old carbon previously stored in soil horizons. Riverine carbon export in the Wuding catchment has been greatly modified by check dams. Our estimate shows that carbon burial through sediment storage was (7.8±4.1)×1010 g C year−1, representing 42% of the total riverine carbon export from terrestrial ecosystems on an annual basis ((18.5±4.5)×1010 g C year−1). Moreover, the riverine carbon export accounted for 16 % of the catchment NEP. It appears that the magnitude of carbon sink of terrestrial ecosystems in this arid-semiarid catchment has been significantly offset by riverine carbon export.

scholarly journals Major role of marine vegetation on the oceanic carbon cycle

2005 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
C. M. Duarte ◽  
J. J. Middelburg ◽  
N. Caraco
Keyword(s):  
Organic Carbon ◽  
Salt Marshes ◽  
Total Carbon ◽  
Organic Carbon Content ◽  
Top Down ◽  
Coastal Habitats ◽  
Bottom Up ◽  
Seagrass Meadows ◽  
Carbon Burial ◽  
Oceanic Carbon

Abstract. The carbon burial in vegetated sediments, ignored in past assessments of carbon burial in the ocean, was evaluated using a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes and mangrove forests) to the global level and a top-down approach derived from considerations of global sediment balance and a compilation of the organic carbon content of vegeatated sediments. Up-scaling of individual burial estimates values yielded a total carbon burial in vegetated habitats of 111 Tmol C y-1. The total burial in unvegetated sediments was estimated to be 126 Tg C y-1, resulting in a bottom-up estimate of total burial in the ocean of about 244 Tg C y-1, two-fold higher than estimates of oceanic carbon burial that presently enter global carbon budgets. The organic carbon concentrations in vegetated marine sediments exceeds by 2 to 10-fold those in shelf/deltaic sediments. Top-down recalculation of ocean sediment budgets to account for these, previously neglected, organic-rich sediments, yields a top-down carbon burial estimate of 216 Tg C y-1, with vegetated coastal habitats contributing about 50%. Even though vegetated carbon burial contributes about half of the total carbon burial in the ocean, burial represents a small fraction of the net production of these ecosystems, estimated at about 3388 Tg C y-1, suggesting that bulk of the benthic net ecosystem production must support excess respiration in other compartments, such as unvegetated sediments and the coastal pelagic compartment. The total excess organic carbon available to be exported to the ocean is estimated at between 1126 to 3534 Tg C y-1, the bulk of which must be respired in the open ocean. Widespread loss of vegetated coastal habitats must have reduced carbon burial in the ocean by about 30 Tg C y-1, identifying the destruction of these ecosystems as an important loss of CO2 sink capacity in the biosphere.

scholarly journals Methane emissions partially offset “blue carbon” burial in mangroves

2018 ◽  
Vol 4 (6) ◽  
pp. eaao4985 ◽  
Author(s):  
Judith A. Rosentreter ◽  
Damien T. Maher ◽  
Dirk V. Erler ◽  
Rachel H. Murray ◽  
Bradley D. Eyre
Keyword(s):  
Methane Emissions ◽  
Blue Carbon ◽  
Carbon Burial

scholarly journals A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO 2

2011 ◽  
Vol 9 (10) ◽  
pp. 552-560 ◽  
Author(s):  
Elizabeth Mcleod ◽  
Gail L Chmura ◽  
Steven Bouillon ◽  
Rodney Salm ◽  
Mats Björk ◽  
...  
Keyword(s):  
Blue Carbon ◽  
Coastal Habitats

scholarly journals Major role of marine vegetation on the oceanic carbon cycle

2004 ◽  
Vol 1 (1) ◽  
pp. 659-679 ◽  
Author(s):  
C. M. Duarte ◽  
J. J. Middelburg ◽  
N. Caraco
Keyword(s):  
Organic Carbon ◽  
Salt Marshes ◽  
Total Carbon ◽  
Organic Carbon Content ◽  
Top Down ◽  
Coastal Habitats ◽  
Bottom Up ◽  
Seagrass Meadows ◽  
Carbon Burial ◽  
Oceanic Carbon

Abstract. The carbon burial in vegetated sediments, ignored in past assessments of carbon burial in the ocean, was evaluated using a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes and mangrove forests) to the global level and a top-down approach derived from considerations of global sediment balance and a compilation of the organic carbon content of vegeatated sediments. Up-scaling of individual burial estimates values yielded a total carbon burial in vegetated habitats of 111 Tg C y-1. The total burial in unvegetated sediments was estimated to be 126 Tg C y-1, resulting in a bottom-up estimate of total burial in the ocean of 244 Tg C y-1, two-fold higher than estimates of oceanic carbon burial that presently enter global carbon budgets. The organic carbon concentrations in vegetated marine sediments exceeds by 2 to 10-fold those in shelf/deltaic sediments. Top-down recalculation of ocean sediment budgets to account for these, previously neglected, organic-rich sediments, yields a top-down carbon burial estimate of 197 Tg C y-1, with vegetated coastal habitats contributing about 50%. Even though vegetated carbon burial contribute about half of the total carbon burial in the ocean, burial represents a small fraction of the net production of these ecosystems, estimated at about 3031 Tg C y-1, suggesting that bulk of the benthic NEP must support excess respiration in other compartments, such as unvegetated sediments and the coastal pelagic compartment. The total excess organic carbon available to be exported to the ocean is estimated at between 769 to 3177 Tg C y-1, the bulk of which must be respired in the open ocean. Widespread loss of vegetated coastal habitats must have reduced carbon burial in the ocean by about 30 Tg C y-1, identifying the destruction of these ecosystems as an important loss of CO2 sink capacity in the biosphere.

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