The mangrove blue carbon sink potential: Evidence from three net primary production assessment methods

Abstract. Recent studies based on remote sensing and carbon process models have revealed that terrestrial net primary production (NPP) in the middle and high latitudes of the Northern Hemisphere has increased significantly; this is crucial for explaining the increased terrestrial carbon sink in the past several decades. Regional NPP estimation based on significant field data, however, has been rare. In this study, we estimated the long-term changes in aboveground NPP (ANPP) for Japan's forests from 1980 to 2005 using forest inventory data, direct field measurements, and an allometric method. The overall ANPP for all forest types averaged 10.5 Mg ha−1 yr−1, with a range of 9.6 to 11.5 Mg ha−1 yr−1, and ANPP for the whole country totaled 249.1 Tg yr−1 (range: 230.0 to 271.4 Tg yr−1) during the study period. Over the 25 years, the net effect of increased ANPP in needle-leaf forests and decreased ANPP in broadleaf forests has led to an increase of 1.9 Mg ha−1 yr−1 (i.e., 0.79 % yr−1). This increase may be mainly due to the establishment of plantations and the rapid early growth of these planted forests.

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Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

Biogeosciences ◽

10.5194/bg-13-1597-2016 ◽

2016 ◽

Vol 13 (5) ◽

pp. 1597-1607 ◽

Cited By ~ 5

Author(s):

Wolfgang Buermann ◽

Claudie Beaulieu ◽

Bikash Parida ◽

David Medvigy ◽

George J. Collatz ◽

...

Keyword(s):

Climate Variability ◽

Primary Production ◽

North Atlantic ◽

Large Scale ◽

Net Primary Production ◽

Carbon Sink ◽

Northern Eurasia ◽

Sink Strength ◽

Independent Evidence ◽

The North

Abstract. The world's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, have uncovered an abrupt, substantial ( ∼  1 PgC yr−1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been ∼  30 % larger than observed (or ∼  12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production significantly increased in the late 1980s (more so than heterotrophic respiration), consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

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Inventory-based estimation of aboveground net primary production in Japan's forests from 1980 to 2005

Biogeosciences Discussions ◽

10.5194/bgd-8-1463-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 1463-1481 ◽

Cited By ~ 1

Author(s):

Y. Wang ◽

J. Y. Fang ◽

T. Kato ◽

Z. D. Guo ◽

B. Zhu ◽

...

Keyword(s):

Primary Production ◽

Net Primary Production ◽

Carbon Sink ◽

Field Measurements ◽

Process Models ◽

Aboveground Net Primary Production ◽

Planted Forests ◽

The Past ◽

Terrestrial Carbon Sink

Abstract. Recent studies based on remote sensing and carbon process models have revealed that terrestrial net primary production (NPP) in the middle and high latitudes of the Northern Hemisphere has increased significantly; this is crucial for explaining the increased terrestrial carbon sink in the past several decades. Regional NPP estimation based on significant field data, however, has been rare. In this study, we estimated the long-term changes in aboveground NPP (ANPP) for Japan's forests from 1980 to 2005, using forest inventory data, direct field measurements, and an allometric method. The overall ANPP for all forest types averaged 10.5 Mg ha−1 yr−1, with a range of 9.6 to 11.5 Mg ha−1 yr−1, and ANPP for the whole country totaled 249.1 Tg yr−1 (range: 230.0 to 271.4 Tg yr−1) during the study period. Over the 25 years, the net effect of increased ANPP in needle-leaf forests and decreased ANPP in broadleaf forests has led to an increase of 1.9 Mg ha−1 yr−1 (i.e., 0.79% yr−1). This increase may be mainly due to the establishment of plantations and the rapid early growth of these planted forests.

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Change in net primary production and heterotrophic respiration: How much is necessary to sustain the terrestrial carbon sink?

Global Biogeochemical Cycles ◽

10.1029/96gb01667 ◽

1996 ◽

Vol 10 (4) ◽

pp. 711-726 ◽

Cited By ~ 89

Author(s):

Matthew V. Thompson ◽

James T. Randerson ◽

Carolyn M. Malmström ◽

Christopher B. Field

Keyword(s):

Primary Production ◽

Net Primary Production ◽

Carbon Sink ◽

Heterotrophic Respiration ◽

Terrestrial Carbon ◽

Terrestrial Carbon Sink

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Neglecting plant–microbe symbioses leads to underestimation of modeled climate impacts

Biogeosciences ◽

10.5194/bg-16-457-2019 ◽

2019 ◽

Vol 16 (2) ◽

pp. 457-465 ◽

Cited By ~ 6

Author(s):

Mingjie Shi ◽

Joshua B. Fisher ◽

Richard P. Phillips ◽

Edward R. Brzostek

Keyword(s):

Climate Change ◽

Primary Production ◽

Climate Model ◽

Net Primary Production ◽

Carbon Sink ◽

Climate Impacts ◽

Nitrogen Acquisition ◽

Carbon Cost ◽

Precipitation Regimes ◽

Microbial Symbionts

Abstract. The extent to which terrestrial ecosystems slow climate change by sequestering carbon hinges in part on nutrient limitation. We used a coupled carbon–climate model that accounts for the carbon cost to plants of supporting nitrogen-acquiring microbial symbionts to explore how nitrogen limitation affects global climate. To do this, we first calculated the reduction in net primary production due to the carbon cost of nitrogen acquisition. We then used a climate model to estimate the impacts of the resulting increase in atmospheric CO2 on temperature and precipitation regimes. The carbon costs of supporting symbiotic nitrogen uptake reduced net primary production by 8.1 Pg C yr−1, with the largest absolute effects occurring in tropical forest biomes and the largest relative changes occurring in boreal and alpine biomes. Globally, our model predicted relatively small changes in climate due to the carbon cost of nitrogen acquisition with temperature increasing by 0.1 ∘C and precipitation decreasing by 6 mm yr−1. However, there were strong regional impacts, with the largest impact occurring in boreal and alpine ecosystems, where such costs were estimated to increase temperature by 1.0 ∘C and precipitation by 9 mm yr−1. As such, our results suggest that carbon expenditures to support nitrogen-acquiring microbial symbionts have critical consequences for Earth's climate, and that carbon–climate models that omit these processes will overpredict the land carbon sink and underpredict climate change.

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Comment: Blue carbon is not substantial in Australian kelp forests

10.31219/osf.io/et2n3 ◽

2020 ◽

Author(s):

John Barry Gallagher

Keyword(s):

Primary Production ◽

Greenhouse Gas ◽

Conceptual Model ◽

Carbon Stock ◽

Net Primary Production ◽

Carbon Stocks ◽

Blue Carbon ◽

Greenhouse Gas Mitigation ◽

Kelp Forests ◽

Southern Reef

Blue carbon refers to the greenhouse gas mitigation services, regarded as primarily supplied by seagrass, mangrove, and saltmarsh relative to a likely alternative ecosystem1. However, a recent study calculates that kelp forests across the Australian Great Southern Reef (GSR) represent globally significant blue carbon stocks and sequestration services, suggesting that these ecosystems should be explicitly included within the blue carbon conceptual model. The article brings together data on the ostensibly Ecklonia radiata assemblage of the GSR in a worthy attempt to quantify the magnitude and importance of these systems as carbon sinks. Their sequestration calculations are based on the fraction of Ecklonia’s net primary production (NPP) that is either buried in adjacent sediments or exported away to the deeper parts of the ocean. The article also makes a carbon stock comparison between kelp forests and seagrass, mangrove, and saltmarsh ecosystems, which is based on the remnant standing biomass of these systems in Australia.

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Carbon cycle uncertainty in the Alaskan Arctic

Biogeosciences ◽

10.5194/bg-11-4271-2014 ◽

2014 ◽

Vol 11 (15) ◽

pp. 4271-4288 ◽

Cited By ~ 51

Author(s):

J. B. Fisher ◽

M. Sikka ◽

W. C. Oechel ◽

D. N. Huntzinger ◽

J. R. Melton ◽

...

Keyword(s):

Climate Change ◽

Carbon Cycle ◽

Primary Production ◽

Net Primary Production ◽

Carbon Sink ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

The Arctic ◽

Regional Patterns ◽

Alaskan Arctic

Abstract. Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for the Alaskan Arctic from four recent model intercomparison projects – NACP (North American Carbon Program) site and regional syntheses, TRENDY (Trends in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland CH4 Inter-comparison of Models Project) – we provide a baseline of terrestrial carbon cycle uncertainty, defined as the multi-model standard deviation (σ) for each quantity that follows. Mean annual absolute uncertainty was largest for soil carbon (14.0 ± 9.2 kg C m−2), then gross primary production (GPP) (0.22 ± 0.50 kg C m−2 yr−1), ecosystem respiration (Re) (0.23 ± 0.38 kg C m−2 yr−1), net primary production (NPP) (0.14 ± 0.33 kg C m−2 yr−1), autotrophic respiration (Ra) (0.09 ± 0.20 kg C m−2 yr−1), heterotrophic respiration (Rh) (0.14 ± 0.20 kg C m−2 yr−1), net ecosystem exchange (NEE) (−0.01 ± 0.19 kg C m−2 yr−1), and CH4 flux (2.52 ± 4.02 g CH4 m−2 yr−1). There were no consistent spatial patterns in the larger Alaskan Arctic and boreal regional carbon stocks and fluxes, with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic and larger boreal region.

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Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

Biogeosciences Discussions ◽

10.5194/bgd-12-13767-2015 ◽

2015 ◽

Vol 12 (16) ◽

pp. 13767-13791

Author(s):

W. Buermann ◽

C. Beaulieu ◽

B. Parida ◽

D. Medvigy ◽

G. J. Collatz ◽

...

Keyword(s):

Climate Variability ◽

Primary Production ◽

North Atlantic ◽

Large Scale ◽

Net Primary Production ◽

Carbon Sink ◽

Northern Eurasia ◽

Sink Strength ◽

Independent Evidence ◽

The North

Abstract. The World's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, uncovered an abrupt, substantial (~ 1 PgC yr−1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been ~ 30 % larger than observed (or ~ 12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production has significantly increased in the late 1980s (more so than heterotrophic respiration) consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

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Carbon cycle uncertainty in the Alaskan Arctic

Biogeosciences Discussions ◽

10.5194/bgd-11-2887-2014 ◽

2014 ◽

Vol 11 (2) ◽

pp. 2887-2932 ◽

Cited By ~ 2

Author(s):

J. B. Fisher ◽

M. Sikka ◽

W. C. Oechel ◽

D. N. Huntzinger ◽

J. R. Melton ◽

...

Keyword(s):

Climate Change ◽

Carbon Cycle ◽

Primary Production ◽

Net Primary Production ◽

Carbon Sink ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

The Arctic ◽

Regional Patterns ◽

Alaskan Arctic

Abstract. Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for Alaska, we provide a baseline of terrestrial carbon cycle structural and parametric uncertainty, defined as the multi-model standard deviation (σ) against the mean (x) for each quantity. Mean annual uncertainty (σ/x) was largest for net ecosystem exchange (NEE) (−0.01± 0.19 kg C m−2 yr−1), then net primary production (NPP) (0.14 ± 0.33 kg C m−2 yr−1), autotrophic respiration (Ra) (0.09 ± 0.20 kg C m−2 yr−1), gross primary production (GPP) (0.22 ± 0.50 kg C m−2 yr−1), ecosystem respiration (Re) (0.23 ± 0.38 kg C m−2 yr−1), CH4 flux (2.52 ± 4.02 g CH4 m−2 yr−1), heterotrophic respiration (Rh) (0.14 ± 0.20 kg C m−2 yr−1), and soil carbon (14.0± 9.2 kg C m−2). The spatial patterns in regional carbon stocks and fluxes varied widely with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Additionally, a feedback (i.e., sensitivity) analysis was conducted of 20th century NEE to CO2 fertilization (β) and climate (γ), which showed that uncertainty in γ was 2x larger than that of β, with neither indicating that the Alaskan Arctic is shifting towards a certain net carbon sink or source. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic.

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