The renaissance of Odum's outwelling hypothesis in 'Blue Carbon' science

Estuarine Coastal and Shelf Science, Journal Year: 2021, Volume and Issue: 255, P. 107361 - 107361

Published: April 3, 2021

The term 'Blue Carbon' was coined about a decade ago to highlight the important carbon sequestration capacity of coastal vegetated ecosystems. has paved way for development programs and policies that preserve restore these threatened ecosystems climate change mitigation. Blue research focused on quantifying stocks burial rates in sediments or accumulating as biomass. This focus habitat-bound led us losing sight mobile blue fraction. Oceans, largest active reservoir carbon, have become somewhat blind spot. Multiple recent investigations revealed high outwelling (i.e., lateral fluxes horizontal exports) dissolved inorganic (DIC) organic (DOC) well particulate (POC) from habitats. In this paper, we conceptualize mangrove, saltmarsh, seagrass macroalgae ecosystems, diagnose key challenges preventing robust quantification, pave future work integrating framework. Outwelling mangroves saltmarshes is usually dominated by DIC (mostly bicarbonate), while POC seems be major species exported meadows forests. Carbon science still its infancy, estimates remain limited spatially temporally. Nevertheless, existing datasets imply followed ocean storage relevant may exceed local sediment long-term (>centuries) mechanism. If proves correct more data emerge, ignoring underestimate perceived

Language: Английский

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Global Patterns in Marine Sediment Carbon Stocks

Frontiers in Marine Science, Journal Year: 2020, Volume and Issue: 7

Published: March 25, 2020

To develop more accurate global carbon (C) budgets and to better inform management of human activities in the ocean, we need high-resolution estimates marine C stocks. Here quantify sedimentary stocks at a 1-km resolution, find that sediments store 2322 (2239–2391) Pg top 1 m (nearly twice terrestrial soils). Sediments abyss/basin zones account for 79% sediment stock, 49% stock is within 200-mile Exclusive Economic Zones countries. Currently, only ∼2% are located highly fully protected areas prevent disturbance seafloor. Our results show represent large globally important sink. However, lack protection makes them vulnerable disturbances can lead their remineralization CO 2 , further aggravating climate change impacts.

Language: Английский

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Rice paddy soils are a quantitatively important carbon store according to a global synthesis

Communications Earth & Environment, Journal Year: 2021, Volume and Issue: 2(1)

Published: Aug. 6, 2021

Abstract Rice paddies account for ~9% or the world’s cropland area and are characterized by environmental conditions promoting soil organic carbon storage, methane emissions to a lesser extent nitrous oxide emissions. Here, we synthesize data from 612 sites across 51 countries estimate global stocks in paddy soils determine main factors affecting storage. Paddy (0–100 cm) contain 18 Pg worldwide. decrease with increasing mean annual temperature pH, whereas precipitation clay content had minor impacts. Meta-analysis shows that can be increased through several management practices. However, greenhouse gas mitigation storage is generally outweighed increases Our results emphasize key role of cycle, importance minimizing anthropogenic

Language: Английский

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Future carbon emissions from global mangrove forest loss

Global Change Biology, Journal Year: 2021, Volume and Issue: 27(12), P. 2856 - 2866

Published: March 1, 2021

Abstract Mangroves have among the highest carbon densities of any tropical forest. These ‘blue carbon’ ecosystems can store large amounts for long periods, and their protection reduces greenhouse gas emissions supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to Paris Agreement valuation on markets requires predicting how management different land‐uses prevent future increase CO 2 sequestration. We integrated comprehensive global datasets stocks, mangrove distribution, deforestation rates, land‐use drivers a predictive model emissions. project foregone soil sequestration potential under ‘business as usual’ rates loss. Emissions from loss could reach 2391 Tg eq by end century, or 3392 when considering The were predicted in southeast south Asia (West Coral Triangle, Sunda Shelf, Bay Bengal) due conversion aquaculture agriculture, followed Caribbean (Tropical Northwest Atlantic) clearing erosion, Andaman coast Myanmar) north Brazil erosion. Together, these six regions accounted 90% total Mangrove has been slowing, be more than halved if reduced remain future. Notably, location emission hotspots was consistent with every dataset used calculate alternative assumptions about storage Our results indicate need policy actions address arising that managed them.

Language: Английский

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Long‐term, amplified responses of soil organic carbon to nitrogen addition worldwide

Global Change Biology, Journal Year: 2020, Volume and Issue: 27(6), P. 1170 - 1180

Published: Dec. 18, 2020

Abstract Soil organic carbon (SOC) is the largest sink in terrestrial ecosystems and plays a critical role mitigating climate change. Increasing reactive nitrogen (N) caused by anthropogenic N input substantially affects SOC dynamics. However, uncertainties remain concerning effects of addition on both mineral soil layers over time at global scale. Here, we analysed large empirical data set spanning 60 years across 369 sites worldwide to explore temporal dynamics addition. We found that significantly increased globe 4.2% (2.7%–5.8%). increases were amplified from short‐ long‐term durations layers. The positive independent ecosystem types, mean annual temperature precipitation. Our findings suggest largely resulted enhanced plant C soils coupled with reduced loss decomposition amplification was associated microbial biomass respiration under study suggests will enhance sequestration contribute future change mitigation.

Language: Английский

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