scholarly journals Calcification-driven CO 2 emissions exceed “Blue Carbon” sequestration in a carbonate seagrass meadow

2021 ◽  
Vol 7 (51) ◽  
Author(s):  
Bryce R. Van Dam ◽  
Mary A. Zeller ◽  
Christian Lopes ◽  
Ashley R. Smyth ◽  
Michael E. Böttcher ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Seagrass Meadow ◽  
Blue Carbon

scholarly journals Calcification-driven CO2 emissions exceed “Blue Carbon” sequestration in a carbonate seagrass meadow

2021 ◽  
Author(s):  
Bryce Van Dam ◽  
Mary Zeller ◽  
Christian Lopes ◽  
Ashley Smyth ◽  
Michael Böttcher ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Sequestration ◽  
Organic Carbon ◽  
Seagrass Meadow ◽  
Blue Carbon ◽  
Carbonate Sediments ◽  
Seagrass Meadows ◽  
Carbon Burial ◽  
Organic Carbon Burial

Abstract Long-term “blue carbon” burial in seagrass meadows is complicated by other carbon and alkalinity exchanges that shape net carbon sequestration. We measured a suite of such processes, including denitrification, sulfur, and inorganic carbon cycling, and assessed their impact on air-water carbon dioxide exchange in a typical seagrass meadow underlain by carbonate sediments. Contrary to the prevailing concept of seagrass meadows acting as carbon sinks, eddy covariance measurements reveal this ecosystem as a consistent source of carbon dioxide to the atmosphere, at an average rate of 610 ± 990 µmol m-2 hr-1 during our study and 700 ± 660 µmol m-2 hr-1 over an annual cycle. A robust mass-balance shows that net alkalinity consumption by ecosystem calcification explains >95% of the observed carbon dioxide emissions, far exceeding alkalinity generated by net reduced sulfur, iron and organic carbon burial. Isotope geochemistry of porewaters suggests substantial dissolution and re-crystallization of more stable carbonates mediated by sulfide oxidation-induced acidification, enhancing long-term carbonate burial and ultimate carbon dioxide production. We show that the “blue carbon” sequestration potential of calcifying seagrass meadows has been over-estimated, and that in-situ organic carbon burial only offsets a small fraction (<5%) of calcification-induced CO2 emissions. Ocean-based climate change mitigation activities in such calcifying regions should be approached with caution and an understanding that net carbon sequestration may not be possible.

scholarly journals Brazilian Mangroves: Blue Carbon Hotspots of National and Global Relevance to Natural Climate Solutions

2022 ◽  
Vol 4 ◽  
Author(s):  
Andre S. Rovai ◽  
Robert R. Twilley ◽  
Thomas A. Worthington ◽  
Pablo Riul
Keyword(s):  
Carbon Sequestration ◽  
National Level ◽  
Cost Effective ◽  
Woody Biomass ◽  
Carbon Stocks ◽  
Blue Carbon ◽  
Carbon Accumulation ◽  
Amazon Forest ◽  
Nationally Determined Contributions ◽  
Natural Climate

Mangroves are known for large carbon stocks and high sequestration rates in biomass and soils, making these intertidal wetlands a cost-effective strategy for some nations to compensate for a portion of their carbon dioxide (CO2) emissions. However, few countries have the national-level inventories required to support the inclusion of mangroves into national carbon credit markets. This is the case for Brazil, home of the second largest mangrove area in the world but lacking an integrated mangrove carbon inventory that captures the diversity of coastline types and climatic zones in which mangroves are present. Here we reviewed published datasets to derive the first integrated assessment of carbon stocks, carbon sequestration rates and potential CO2eq emissions across Brazilian mangroves. We found that Brazilian mangroves hold 8.5% of the global mangrove carbon stocks (biomass and soils combined). When compared to other Brazilian vegetated biomes, mangroves store up to 4.3 times more carbon in the top meter of soil and are second in biomass carbon stocks only to the Amazon forest. Moreover, organic carbon sequestration rates in Brazilian mangroves soils are 15–30% higher than recent global estimates; and integrated over the country’s area, they account for 13.5% of the carbon buried in world’s mangroves annually. Carbon sequestration in Brazilian mangroves woody biomass is 10% of carbon accumulation in mangrove woody biomass globally. Our study identifies Brazilian mangroves as a major global blue carbon hotspot and suggest that their loss could potentially release substantial amounts of CO2. This research provides a robust baseline for the consideration of mangroves into strategies to meet Brazil’s intended Nationally Determined Contributions.

scholarly journals Improving Estimates of Coastal Carbon Sequestration

Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Carbon Sequestration ◽  
Tidal Marsh ◽  
Blue Carbon ◽  
Carbon Accumulation ◽  
Model Approach

A new two-model approach could reduce uncertainties in calculated rates of “blue carbon” accumulation within soils of seagrass, tidal marsh, and mangrove habitats.

scholarly journals Seagrass Restoration Enhances “Blue Carbon” Sequestration in Coastal Waters

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e72469 ◽  
Author(s):  
Jill T. Greiner ◽  
Karen J. McGlathery ◽  
John Gunnell ◽  
Brent A. McKee
Keyword(s):  
Carbon Sequestration ◽  
Coastal Waters ◽  
Blue Carbon ◽  
Seagrass Restoration

Sediment microbes mediate the impact of nutrient loading on blue carbon sequestration by mixed seagrass meadows

2017 ◽  
Vol 599-600 ◽  
pp. 1479-1484 ◽  
Author(s):  
Songlin Liu ◽  
Zhijian Jiang ◽  
Jingping Zhang ◽  
Yunchao Wu ◽  
Xiaoping Huang ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Nutrient Loading ◽  
Blue Carbon ◽  
Seagrass Meadows ◽  
The Impact ◽  
Sediment Microbes

scholarly journals Effects of shading and simulated grazing on carbon sequestration in a tropical seagrass meadow

2016 ◽  
Vol 104 (3) ◽  
pp. 654-664 ◽  
Author(s):  
Martin Dahl ◽  
Diana Deyanova ◽  
Liberatus D. Lyimo ◽  
Johan Näslund ◽  
Göran S. Samuelsson ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Seagrass Meadow ◽  
Simulated Grazing

scholarly journals Comparison of marine macrophytes for their contributions to blue carbon sequestration

Ecology ◽  
2015 ◽  
Vol 96 (11) ◽  
pp. 3043-3057 ◽  
Author(s):  
Stacey M. Trevathan-Tackett ◽  
Jeffrey Kelleway ◽  
Peter I. Macreadie ◽  
John Beardall ◽  
Peter Ralph ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Blue Carbon ◽  
Marine Macrophytes
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