An airborne regional carbon balance for Central Amazonia

Abstract. We obtained regional estimates of surface CO2 exchange rates using atmospheric boundary layer budgeting techniques above tropical forest near Manaus, Brazil. Comparisons were made with simultaneous measurements from two eddy covariance towers below. Although there was good agreement for daytime measurements, large differences emerged for integrating periods dominated by the night-time fluxes. These results suggest that a systematic underestimation of night time respiratory effluxes may be responsible for the high Amazonian carbon sink suggested by several previous eddy covariance studies. Large CO2 fluxes from riverine sources or high respiratory losses from recently disturbed forests do not need to be invoked in order to balance the carbon budget of the Amazon. Our results do not, however, discount some contribution of these processes to the overall Amazon carbon budget.

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Effects of a windthrow disturbance on the carbon balance of a broadleaf deciduous forest in Hokkaido, Japan

Biogeosciences Discussions ◽

10.5194/bgd-12-10425-2015 ◽

2015 ◽

Vol 12 (13) ◽

pp. 10425-10468

Author(s):

K. Yamanoi ◽

Y. Mizoguchi ◽

H. Utsugi

Keyword(s):

Forest Management ◽

Carbon Balance ◽

Carbon Budget ◽

Deciduous Forest ◽

Carbon Sink ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

White Birch ◽

Eddy Covariance Method ◽

Area Index

Abstract. Forests play an important role in the terrestrial carbon budget, with most being in a carbon sequestration stage. The net carbon releases that occur result from forest disturbance, and windthrow is a typical disturbance event affecting the forest carbon balance in eastern Asia. The carbon budget has been measured using the eddy covariance method in a deciduous broadleaf forest (Japanese white birch, Japanese oak, and castor aralia) in Hokkaido, where accidental damage by the strong typhoon, Songda, in 2004 occurred. We also used the biometrical method to demonstrate the carbon flow within the forest in detail. Damaged trees amounted to 40 % of all trees, and they remained on site where they were not extracted by forest management. Gross primary production (GPP), ecosystem respiration (Re), and net ecosystem production were 1350, 975, and 375 g C m−2 yr−1 before the disturbance and 1262, 1359, and −97 g C m−2 yr−1 2 years after the disturbance, respectively. Before the disturbance, the forest was an evident carbon sink, and it subsequently transformed to net a carbon source. Because of light enrichment at the forest floor, the leaf area index and biomass of the undergrowth (Sasa kurilensis and S. senanensis) increased by factors of 2.4 and 1.7, respectively, in 3 years subsequent to the disturbance. The photosynthesis of Sasa increased rapidly and contributed to the total GPP after the disturbance. The annual GPP only decreased by 6 % just after the disturbance. On the other hand, the annual Re increased by 39 % mainly because of the decomposition of residual coarse-wood debris. The carbon balance after the disturbance was controlled by the new growth and the decomposition of residues. The forest management, which resulted in the dead stands remaining at the study site, strongly affected the carbon budget over the years. When comparing the carbon uptake efficiency at the study site with that at others, including those with various kinds of disturbances, we emphasized the importance of forest management as well as disturbance type in the carbon budget.

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Ventilation of subterranean CO<sub>2</sub> and Eddy covariance incongruities over carbonaceous ecosystems

Biogeosciences Discussions ◽

10.5194/bgd-6-10911-2009 ◽

2009 ◽

Vol 6 (6) ◽

pp. 10911-10934 ◽

Cited By ~ 2

Author(s):

A. Were ◽

P. Serrano-Ortiz ◽

C. Moreno de Jong ◽

L. Villagarcía ◽

F. Domingo ◽

...

Keyword(s):

Eddy Covariance ◽

Ground Penetrating Radar ◽

Carbon Balance ◽

Surface Heterogeneity ◽

Co2 Exchange ◽

Co2 Fluxes ◽

Regression Slope ◽

The World ◽

Radar Measurements ◽

Ground Penetrating

Abstract. Measurements of CO2 fluxes with Eddy Covariance (EC) systems are ongoing over different ecosystems around the world, through different measuring networks, in order to assess the carbon balance of these ecosystems. In carbonaceous ecosystems, characterized by the presence of subterranean pores and cavities, ventilation of the CO2 accumulated in these cavities and pores can act as an extra source of CO2 exchange between the ecosystem and the atmosphere. In this work we analyse the effect of the subterranean heterogeneity of a carbonaceous ecosystem on measurements of CO2 fluxes by comparing measurements from two EC systems with distinct footprints. Results showed that both EC systems agreed for measurements of evapotranspiration and of CO2 in periods when respiratory and photosynthetic processes were dominant (biological periods), with a regression slope of 0.99 and 0.97, respectively. However, in periods when the main source of CO2 comes from the ventilation of subterranean pores and caves (abiotic periods) agreement is not good, with a regression slope of 0.6. Ground-penetrating radar measurements of the sub-surface confirmed the existence of high sub-surface heterogeneity that, combined with different footprints, lead to differences in the measurements of the two EC systems. These results show that measurements of CO2 fluxes with Eddy covariance systems over carbonaceous ecosystems must be taken carefully, as they may not be representative of the ecosystem under consideration.

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Ventilation of subterranean CO<sub>2</sub> and Eddy covariance incongruities over carbonate ecosystems

Biogeosciences ◽

10.5194/bg-7-859-2010 ◽

2010 ◽

Vol 7 (3) ◽

pp. 859-867 ◽

Cited By ~ 19

Author(s):

A. Were ◽

P. Serrano-Ortiz ◽

C. Moreno de Jong ◽

L. Villagarcía ◽

F. Domingo ◽

...

Keyword(s):

Eddy Covariance ◽

Ground Penetrating Radar ◽

Carbon Balance ◽

Surface Heterogeneity ◽

Co2 Exchange ◽

Co2 Fluxes ◽

Regression Slope ◽

The World ◽

Radar Measurements ◽

Ground Penetrating

Abstract. Measurements of CO2 fluxes with Eddy Covariance (EC) systems are ongoing over different ecosystems around the world, through different measuring networks, in order to assess the carbon balance of these ecosystems. In carbonate ecosystems, characterized by the presence of subterranean pores and cavities, ventilation of the CO2 accumulated in these cavities and pores can act as an extra source of CO2 exchange between the ecosystem and the atmosphere. In this work we analyse the effect of the subterranean heterogeneity of a carbonate ecosystem on measurements of CO2 fluxes by comparing measurements from two EC systems with distinct footprints. Results showed that both EC systems agreed for measurements of evapotranspiration and of CO2 in periods when respiratory and photosynthetic processes were dominant (biological periods), with a regression slope of 0.99 and 0.97, respectively. However, in periods when the main source of CO2 comes from the ventilation of subterranean pores and cavities (abiotic periods) agreement is not good, with a regression slope of 0.6. Ground-penetrating radar measurements of the sub-surface confirmed the existence of high sub-surface heterogeneity that, combined with different footprints, lead to differences in the measurements of the two EC systems. These results show that measurements of CO2 fluxes with Eddy covariance systems over carbonate ecosystems must be taken carefully, as they may not be representative of the ecosystem under consideration.

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Anrechnung der CO2-Senken des Schweizer Waldes: Grundlagenpapier und Empfehlungen | Accounting of CO2 sinks in Swiss forests. Working paper and recommendations

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2005.0438 ◽

2005 ◽

Vol 156 (11) ◽

pp. 438-441

Author(s):

Arbeitsgruppe Wald- und ◽

Holzwirtschaft im Klimaschutz

Keyword(s):

Forest Management ◽

Greenhouse Gases ◽

Climate Policy ◽

Federal Government ◽

Kyoto Protocol ◽

Carbon Balance ◽

Carbon Sink ◽

Management Policy ◽

Working Paper ◽

Reduction Of Co2

With the ratification of the Kyoto Protocol aimed at reducing greenhouse gases, Switzerland is committed to reducing CO2emissions by 4.2 million tonnes by 2008. The forests in Switzerland could contribute to the country's national carbon balance with maximum 1.8 million tonnes reduction of CO2. With an increased use of the forest the emissions could be reduced by up to 2 million tonnes by the substitution of other materials. With a targeted forest management policy carbon sink reduction and the substitution value of the forest could be balanced against one another. In the framework of climate policy the Federal government should create the legal and organisational conditions for this.

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Responses of Forest Carbon Cycle to Drought and Elevated CO2

Atmosphere ◽

10.3390/atmos12020212 ◽

2021 ◽

Vol 12 (2) ◽

pp. 212

Author(s):

Jun-Lan Xiao ◽

Feng Zeng ◽

Qiu-Lan He ◽

Yu-Xia Yao ◽

Xiao Han ◽

...

Keyword(s):

Water Stress ◽

Elevated Co2 ◽

Carbon Sink ◽

Ecosystem Respiration ◽

Co2 Exchange ◽

Positive Influence ◽

Research Field ◽

Co2 Fertilization ◽

Global Trends ◽

Elevated Atmospheric Co2

Forests play a pivotal role in mitigating global warming as an important carbon sink. Recent global greening trends reflect a positive influence of elevated atmospheric CO2 on terrestrial carbon uptake. However, increasingly frequent and intense drought events endanger the carbon sequestration function of forests. This review integrates previous studies across scales to identify potential global trends in forest responses to drought and elevated CO2 as well as to identify data needs in this important research field. The inconsistent responses of ecosystem respiration to drought contributes to the change of forest net CO2 exchange, which depends on the balance of opposite effects of warming and water stress on respiration. Whether CO2 fertilization can offset the effects of drought remains controversial, however, we found a potential overestimation of global CO2 fertilization effects because of increasing water stress and other limitations such as light and nutrients (N, P) as well as the possibility of photosynthetic acclimation.

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Global trends in air-water CO2 exchange over seagrass meadows revealed by atmospheric Eddy Covariance

10.1002/essoar.10504484.1 ◽

2020 ◽

Author(s):

Bryce R Van Dam ◽

Pierre Polsenaere ◽

Aylin Barreras-Apodaca ◽

Christian Lopes ◽

Zulia Mayari Sanchez-Mejia ◽

...

Keyword(s):

Eddy Covariance ◽

Co2 Exchange ◽

Global Trends ◽

Seagrass Meadows

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Eddy covariance and biometric measurements show that a savanna ecosystem in Southwest China is a carbon sink

Scientific Reports ◽

10.1038/srep41025 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 11

Author(s):

Xuehai Fei ◽

Yanqiang Jin ◽

Yiping Zhang ◽

Liqing Sha ◽

Yuntong Liu ◽

...

Keyword(s):

Eddy Covariance ◽

Southwest China ◽

Carbon Sink ◽

Biometric Measurements

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Biometric and eddy-covariance-based estimates of carbon balance for a warm-temperate mixed forest in Japan

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2008.01.017 ◽

2008 ◽

Vol 148 (5) ◽

pp. 723-737 ◽

Cited By ~ 46

Author(s):

Yuji Kominami ◽

Mayuko Jomura ◽

Masako Dannoura ◽

Yoshiaki Goto ◽

Koji Tamai ◽

...

Keyword(s):

Eddy Covariance ◽

Carbon Balance ◽

Mixed Forest ◽

Temperate Mixed Forest ◽

Warm Temperate

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Vertical advection and nocturnal deposition of ozone over a boreal pine forest

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-2089-2009 ◽

2009 ◽

Vol 9 (6) ◽

pp. 2089-2095 ◽

Cited By ~ 21

Author(s):

Ü. Rannik ◽

I. Mammarella ◽

P. Keronen ◽

T. Vesala

Keyword(s):

Carbon Dioxide ◽

Eddy Covariance ◽

Turbulence Intensity ◽

Carbon Dioxide Flux ◽

Pine Forest ◽

Night Time ◽

Vertical Advection ◽

Ozone Deposition ◽

Storage Change ◽

Ozone Sink

Abstract. Night-time ozone deposition for a Scots pine forest in Southern Finland was studied at the SMEAR II measurement station by evaluating the turbulent eddy covariance (EC), storage change and vertical advection fluxes. Similarly to night-time carbon dioxide flux, the eddy-covariance flux of ozone was decreasing with turbulence intensity (friction velocity), and storage change of the compound did not compensate the reduction (well-known night-time measurement problem). Accounting for vertical advection resulted in invariance of ozone deposition rate on turbulence intensity. This was also demonstrated for carbon dioxide, verified by independent measurements of NEE by chamber systems. The result highlights the importance of advection when considering the exchange measurements of any scalar. Analysis of aerodynamic and laminar boundary layer resistances by the model approach indicated that the surface resistance and/or chemical sink strength was limiting ozone deposition. The possible aerial ozone sink by known fast chemical reactions with sesquiterpenes and NO explain only a minor fraction of ozone sink. Thus the deposition is controlled either by stomatal uptake or surface reactions or both of them, the mechanisms not affected by turbulence intensity. Therefore invariance of deposition flux on turbulence intensity is expected also from resistance and chemical sink analysis.

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