scholarly journals Impact of peatlands on carbon dioxide (CO<sub>2</sub>) emissions from the Rajang River and Estuary, Malaysia

2018 ◽  
Author(s):  
Denise Müller-Dum ◽  
Thorsten Warneke ◽  
Tim Rixen ◽  
Moritz Müller ◽  
Antje Baum ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Co2 Flux ◽  
Southeast Asian ◽  
Dry Season ◽  
Carbon Dioxide Partial Pressure ◽  
Wet Season ◽  
Peat Deposits ◽  
Carbon Dioxide Co2

Abstract. Tropical peat-draining rivers are known as potentially large sources of carbon dioxide (CO2) to the atmosphere due to high loads of carbon they receive from surrounding soils. However, not many seasonally resolved data are available, limiting our understanding of these systems. We report the first measurements of carbon dioxide partial pressure (pCO2) in the Rajang River and Estuary, the longest river in Malaysia. The Rajang River catchment is characterized by extensive peat deposits found in the delta region, and by human impact such as logging, land use and river damming. pCO2 averaged 2919 ± 573 µatm during the wet season and 2732 ± 443 µatm during the dry season. This is at the low end of reported values for Southeast Asian peat-draining rivers, but higher than values reported for Southeast Asian rivers that do not flow through peat deposits. However, dissolved inorganic carbon (DIC) and δ13C-DIC data did not suggest that peatlands were an important source of inorganic carbon to the river, with an average DIC concentration of 203.9 ± 59.6 µmol L−1 and an average δ13C-DIC of −8.06 ± 1.90 ‰. Also, compared to rivers with similar peat coverage, the pCO2 in the Rajang was rather low. Thus, we suggest that peat coverage is, by itself, insufficient as sole predictor of CO2 emissions from peat-draining rivers, and that other factors, like the spatial distribution of peat in the catchment and pH, need to be considered as well. In the Rajang River, peatlands probably do not contribute much to the CO2 flux due to the proximity of the peatlands to the coast. CO2 fluxes to the atmosphere were 2.28 ± 0.52 gC m−2 d−1 (wet season) and 2.45 ± 0.45 gC m−2 d−1 (dry season), making the Rajang River a moderate source of carbon to the atmosphere.

scholarly journals Impact of peatlands on carbon dioxide (CO<sub>2</sub>) emissions from the Rajang River and Estuary, Malaysia

2019 ◽  
Vol 16 (1) ◽  
pp. 17-32 ◽  
Author(s):  
Denise Müller-Dum ◽  
Thorsten Warneke ◽  
Tim Rixen ◽  
Moritz Müller ◽  
Antje Baum ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Flux ◽  
Southeast Asian ◽  
Dry Season ◽  
Carbon Dioxide Partial Pressure ◽  
Gas Transfer ◽  
Wet Season ◽  
Transfer Velocity ◽  
Organic C ◽  
Peat Deposits

Abstract. Tropical peat-draining rivers are known as potentially large sources of carbon dioxide (CO2) to the atmosphere due to the high loads of carbon they receive from surrounding soils. However, not many seasonally resolved data are available, limiting our understanding of these systems. We report the first measurements of carbon dioxide partial pressure (pCO2) in the Rajang River and Estuary, the longest river in Malaysia. The Rajang River catchment is characterized by extensive peat deposits found in the delta region, and by human impact such as logging, land use and river damming. pCO2 averaged 2540±189 µatm during the wet season and 2350±301 µatm during the dry season. Using three different parameterizations for the gas transfer velocity, calculated CO2 fluxes to the atmosphere were 1.5 (0.5–2.0) g C m−2 d−1 (mean, minimum – maximum) during the wet season and 1.7 (0.6–2.6) g C m−2 d−1 during the dry season. This is at the low end of reported values for Southeast Asian peat-draining rivers, but similar to values reported for Southeast Asian rivers that do not flow through peat deposits. In the Rajang River, peatlands probably do not contribute much to the CO2 flux due to the proximity of the peatlands to the coast, which limits the opportunity for degradation of organic C during transport. Thus, we suggest that peat coverage is, by itself, insufficient as the sole predictor of CO2 emissions from peat-draining rivers, and that other factors, like the spatial distribution of peat in the catchment and pH, also need to be considered.

scholarly journals Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

2014 ◽  
Vol 11 (3) ◽  
pp. 4251-4299 ◽  
Author(s):  
E. M. Thaysen ◽  
D. Jacques ◽  
S. Jessen ◽  
C. E. Andersen ◽  
E. Laloy ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Vadose Zone ◽  
Inorganic Carbon ◽  
Plant Biomass ◽  
Dissolved Inorganic Carbon ◽  
Carbon Fluxes ◽  
Atmospheric Co2 ◽  
Carbon Dioxide Partial Pressure ◽  
Post Harvest ◽  
Unplanted Soil

Abstract. The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles, and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modelled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol carbon (C) m−2 s−1, respectively, and largely exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Plant biomass and soil pCO2 were high in the mesocosms as compared to a standard field situation. Our results indicate no change of the cropland C balance under elevated atmospheric CO2 in a warmer future climate, in which plant biomass and soil pCO2 are expected to increase.

scholarly journals Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

2014 ◽  
Vol 11 (24) ◽  
pp. 7179-7192 ◽  
Author(s):  
E. M. Thaysen ◽  
D. Jacques ◽  
S. Jessen ◽  
C. E. Andersen ◽  
E. Laloy ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Plant Growth ◽  
Vadose Zone ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Carbon Dioxide Partial Pressure ◽  
Co2 Production ◽  
Post Harvest ◽  
Unplanted Soil ◽  
Soil Mesocosms

Abstract. The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying mechanisms. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modeled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol C m−2 s−1, respectively, and grossly exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Plant biomass was high in the mesocosms as compared to a standard field situation. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one-third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Modeling suggested that increasing soil alkalinity during plant growth was due to nutrient buffering during root nitrate uptake.

scholarly journals CO<sub>2</sub> perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

2009 ◽  
Vol 6 (2) ◽  
pp. 4441-4462 ◽  
Author(s):  
K. G. Schulz ◽  
J. Barcelos e Ramos ◽  
R. E. Zeebe ◽  
U. Riebesell
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Carbonate Chemistry ◽  
Surface Ocean ◽  
Seawater Carbonate Chemistry ◽  
Similarities And Differences ◽  
Carbon Dioxide Co2

Abstract. Increasing atmospheric carbon dioxide (CO2) through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3

scholarly journals Hydrochemistry and Dissolved Inorganic Carbon (DIC) Cycling in a Tropical Agricultural River, Mun River Basin, Northeast Thailand

2019 ◽  
Vol 16 (18) ◽  
pp. 3410 ◽  
Author(s):  
Xiaoqiang Li ◽  
Guilin Han ◽  
Man Liu ◽  
Chao Song ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Surface Water ◽  
Carbon Isotope ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Anthropogenic Activities ◽  
Co2 Flux ◽  
Carbon Isotope Composition ◽  
Human Disturbances

Dissolved inorganic carbon isotope composition (δ13CDIC), together with major ion concentrations were measured in the Mun River and its tributaries in March 2018 to constrain the origins and cycling of dissolved inorganic carbon. In the surface water samples, the DIC content ranged from 185 to 5897 μmol/L (average of 1376 μmol/L), and the δ13CDIC of surface water ranged from −19.6‰ to −2.7‰. In spite of the high variability in DIC concentrations and partial pressure of carbon dioxide (pCO2), the δ13CDIC values of the groundwater were relatively consistent, with a mean value of −16.9 ± 1.4‰ (n = 9). Spatial changes occurred in the direction and magnitude of CO2 flux through water-air interface (FCO2). In the dry season, fluxes varied from −6 to 1826 mmol/(m2·d) with an average of 240 mmol/(m2·d). In addition to the dominant control on hydrochemistry and dissolved inorganic carbon isotope composition by the rock weathering, the impacts from anthropogenic activities were also observed in the Mun River, especially higher DIC concentration of waste water from urban activities. These human disturbances may affect the accurate estimate contributions of carbon dioxide from tropical rivers to the atmospheric carbon budgets.

scholarly journals Technical Note: Mesocosm approach to quantify dissolved inorganic carbon percolation fluxes

2014 ◽  
Vol 11 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
E. M. Thaysen ◽  
S. Jessen ◽  
P. Ambus ◽  
C. Beier ◽  
D. Postma ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Experimental Period ◽  
Technical Note ◽  
Transport Processes ◽  
Carbon Dioxide Partial Pressure ◽  
Physical Factors ◽  
Soil Carbon Dioxide ◽  
Promising Tool ◽  
Unplanted Soil

Abstract. Dissolved inorganic carbon (DIC) fluxes across the vadose zone are influenced by a complex interplay of biological, chemical and physical factors. A novel soil mesocosm system was evaluated as a tool for providing information on the mechanisms behind DIC percolation to the groundwater from unplanted soil. Carbon dioxide partial pressure (pCO2), alkalinity, soil moisture and temperature were measured with depth and time, and DIC in the percolate was quantified using a sodium hydroxide trap. Results showed good reproducibility between two replicate mesocosms. The pCO2 varied between 0.2 and 1.1%, and the alkalinity was 0.1–0.6 meq L−1. The measured cumulative effluent DIC flux over the 78-day experimental period was 185–196 mg L−1 m−2 and in the same range as estimates derived from pCO2 and alkalinity in samples extracted from the side of the mesocosm column and the drainage flux. Our results indicate that the mesocosm system is a promising tool for studying DIC percolation fluxes and other biogeochemical transport processes in unsaturated environments.

scholarly journals Groundwater data improve modelling of headwater stream CO<sub>2</sub> outgassing with a stable DIC isotope approach

2017 ◽  
Author(s):  
Anne Marx ◽  
Marcus Conrad ◽  
Vadym Aizinger ◽  
Alexander Prechtel ◽  
Robert van Geldern ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Temporal Variations ◽  
Headwater Stream ◽  
Integral Approach ◽  
Gas Transfer ◽  
Transfer Velocity ◽  
Outgassing Rate ◽  
Carbon Dioxide Co2

Abstract. A large portion of terrestrially-derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams was indicated as highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e., 0.93 petagrams C yr−1) of total CO2 outgassing from all rivers and streams worldwide. In this study, stream pCO2, dissolved inorganic carbon (DIC) and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlirska catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle, that the 13C / 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k) that is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed 80 % to the annual stream inorganic carbon loss in the Uhlirska catchment. This translated to a CO2 outgassing rate from the stream of 5.2 t C yr−1 and to 2.9 g C m−2 yr−1, when normalised to the catchment area. Large temporal variations with maximum values during spring snowmelt and summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.

scholarly journals Impact of seawater <i>p</i>CO<sub>2</sub> on calcification and Mg/Ca and Sr/Ca ratios in benthic foraminifera calcite: results from culturing experiments with <i>Ammonia tepida</i>

2010 ◽  
Vol 7 (1) ◽  
pp. 81-93 ◽  
Author(s):  
D. Dissard ◽  
G. Nehrke ◽  
G. J. Reichart ◽  
J. Bijma
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Benthic Foraminifera ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Planktonic Foraminifera ◽  
Ambient Conditions ◽  
Precipitated Calcium Carbonate ◽  
Shell Weight ◽  
Dissolved Carbon

Abstract. Evidence of increasing concentrations of dissolved carbon dioxide, especially in the surface ocean and its associated impacts on calcifying organisms, is accumulating. Among these organisms, benthic and planktonic foraminifera are responsible for a large amount of the globally precipitated calcium carbonate. Hence, their response to an acidifying ocean may have important consequences for future inorganic carbon cycling. To assess the sensitivity of benthic foraminifera to changing carbon dioxide levels and subsequent alteration in seawater carbonate chemistry, we cultured specimens of the shallow water species Ammonia tepida at two concentrations of atmospheric CO2 (230 and 1900 ppmv) and two temperatures (10 °C and 15 °C). Shell weights and elemental compositions were determined. Impact of high and low pCO2 on elemental composition are compared with results of a previous experiment were specimens were grown under ambient conditions (380 ppvm, no shell weight measurements of specimen grown under ambient conditions are, however, available). Results indicate that shell weights decrease with decreasing [CO32−], although calcification was observed even in the presence of calcium carbonate under-saturation, and also decrease with increasing temperature. Thus both warming and ocean acidification may act to decrease shell weights in the future. Changes in [CO32−] or total dissolved inorganic carbon do not affect the Mg distribution coefficient. On the contrary, Sr incorporation is enhanced under increasing [CO32−]. Implications of these results for the paleoceanographic application of foraminifera are discussed.

scholarly journals Installing kelp forests/seaweed beds for mitigation and adaptation against global warming: Korean Project Overview

2013 ◽  
Vol 70 (5) ◽  
pp. 1038-1044 ◽  
Author(s):  
Ik Kyo Chung ◽  
Jung Hyun Oak ◽  
Jin Ae Lee ◽  
Jong Ahm Shin ◽  
Jong Gyu Kim ◽  
...  
Keyword(s):  
Global Warming ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Coastal Region ◽  
Pharmaceutical Products ◽  
Kelp Forests ◽  
Co2 Removal ◽  
Mitigation And Adaptation ◽  
Southern Korea ◽  
Carbon Dioxide Co2

Abstract Chung, I. K., Oak, J. H., Lee, J. A., Shin, J. A., Kim, J. G., and Park, K.-S. 2013. Installing kelp forests/seaweed beds for mitigation and adaptation against global warming: Korean Project Overview. – ICES Journal of Marine Science, 70: 1038–1044. Seaweed beds can serve as a significant carbon dioxide (CO2) sink while also satisfying global needs for food, fodder, fuel, and pharmaceutical products. The goal of our Korean Project has been to develop new baseline and monitoring methodologies for mitigation and adaptation within the context of climate change. Using innovative research approaches, we have established the Coastal CO2 Removal Belt (CCRB), which comprises both natural and man-made plant communities in the coastal region of southern Korea. Implemented on various spatial–temporal scales, this scheme promotes the removal of CO2 via marine forests. For example, when populated with the perennial brown alga Ecklonia, a pilot CCRB farm can draw down ∼10 t of CO2 per ha per year. This success is manifested by an increment in biomass accumulations and a decrease in the amount of dissolved inorganic carbon in the water column.

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