scholarly journals Spatial Patterns of Organic and Inorganic Carbon in Lake Qinghai Surficial Sediments and Carbon Burial Estimation

2021 ◽  
Vol 9 ◽  
Author(s):  
Xi Chen ◽  
Xianqiang Meng ◽  
Yinxian Song ◽  
Bin Zhang ◽  
Zhiwei Wan ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Budget ◽  
Inorganic Carbon ◽  
Carbon Pool ◽  
Total Carbon ◽  
Tibet Plateau ◽  
Lake Area ◽  
Lake Qinghai ◽  
Carbon Burial ◽  
Global Carbon

Lake carbon burial is of vital significance in global carbon cycle and carbon budget, particularly in the large deepwater lakes. However, carbon burial in large deepwater lakes is hard to estimate due to the difficulty in obtaining high spatial-resolution samples. In this study, we investigated distributions of total organic carbon (TOC) and inorganic carbon (TIC), two main carbon components in lake sediments, based on dozens of surficial sedimentary samples (n = 26) covering whole Lake Qinghai, the largest saline lake in China. The results showed that the TOC content, with a range of 1.4–4.8%, was significantly higher in the lake area near the northern lakeshore where human activities are concentrated and lower in the lake areas near the Buha River mouth and the eastern lake area. In contrast, the TIC content, ranging from 1.5 to 3.8%, increased from the northwestern and southeastern lake areas toward the lake center, and mainly depended on hydro-chemical and hydraulic characteristics. The inorganic carbon burial (47.77 ± 19.73 Gg C yr−1) was approximately equal to organic carbon burial (47.50 ± 22.68 Gg C yr−1) and accounted for about 50% of the total carbon burial (95.27 ± 37.74 Gg C yr−1), suggesting that saline lakes constitute a large inorganic carbon pool in addition to an organic carbon pool. Because of saline water body type in arid and semiarid regions and alpine Qinghai–Tibet Plateau, lakes in these regions have huge inorganic carbon burial potential and important contributions to the global carbon budget.

Carbon storage in cotton soils of northern New South Wales

Soil Research ◽  
2003 ◽  
Vol 41 (5) ◽  
pp. 889 ◽  
Author(s):  
T. A. Knowles ◽  
B. Singh
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Soil Carbon ◽  
Inorganic Carbon ◽  
Carbon Pool ◽  
Total Carbon ◽  
Soil Types ◽  
Soil Carbon Pool ◽  
Total Soil

Soil carbon is an important component of the global carbon cycle with an estimated pool of soil organic carbon of about 1500 Gt. There are few estimates of the pool of inorganic carbon, but it is thought to be approximately 50% of the organic carbon pool. There is no detailed study on the estimation of the soil carbon pool for Australian soils.In order to quantify the carbon pools and to determine the extent of spatial variability in the organic and inorganic carbon pools, 120 soil cores were taken down to a depth of 0.90 m from a typical cotton field in northern NSW. Three cores were also taken from nearby virgin bushland and these samples were used as paired samples. Each soil core was separated into 4 samples, i.e. 0–0.15, 0.15–0.30, 0.30–0.60, and 0.60–0.90 m. Soil organic carbon was determined by wet oxidation and inorganic carbon content was determined using the difference between total carbon and organic carbon, and confirmed by the acid dissolution method. Total carbon was measured using a LECO CHN analyser. Soil organic carbon of the field constituted 62% (0–0.15 m), 58% (0.15–0.30 m), 60% (0.30–0.60 m), and 67% (0.60–0.90 m) of the total soil carbon. The proportion of inorganic carbon in total carbon is higher than the global average of 32%. Organic carbon content was relatively higher in the deeper layers (>0.30�m) of the studied soils (Vertosols) compared with other soil types of Australia. The carbon content varied across the field, however, there was little correlation between the soil types (grey, red, or intergrade colour) and carbon content. The total soil carbon pool of the studied field was estimated to be about 78 t/ha for 0–0.90 m layer, which was approximately 58% of the total soil carbon in the soil under nearby remnant bushland (136 t/ha). The total pool of carbon in the cotton soils of NSW was estimated to be 44.8 Mt C, where organic carbon and inorganic carbon constitute 34.9 Mt C and 9.9 Mt C, respectively. Based on the results of a limited number of paired sites under remnant vegetation, it was estimated that about 18.9 Mt of C has been lost from Vertosols by cotton cropping in NSW. With more sustainable management practices such as conservation tillage and green manuring, some of the lost carbon can be resequestered, which will help to mitigate the greenhouse effect, improve soil quality and may increase crop yield.

scholarly journals Reviews and syntheses: Hidden forests, the role of vegetated coastal habitats in the ocean carbon budget

2017 ◽  
Vol 14 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Carlos M. Duarte
Keyword(s):  
Carbon Sequestration ◽  
Organic Carbon ◽  
Primary Production ◽  
Deep Sea ◽  
Carbon Budget ◽  
Net Primary Production ◽  
Global Ocean ◽  
Coastal Habitats ◽  
Global Carbon Budget ◽  
Global Carbon

Abstract. Vegetated coastal habitats, including seagrass and macroalgal beds, mangrove forests and salt marshes, form highly productive ecosystems, but their contribution to the global carbon budget remains overlooked, and these forests remain hidden in representations of the global carbon budget. Despite being confined to a narrow belt around the shoreline of the world's oceans, where they cover less than 7 million km2, vegetated coastal habitats support about 1 to 10 % of the global marine net primary production and generate a large organic carbon surplus of about 40 % of their net primary production (NPP), which is either buried in sediments within these habitats or exported away. Large, 10-fold uncertainties in the area covered by vegetated coastal habitats, along with variability about carbon flux estimates, result in a 10-fold bracket around the estimates of their contribution to organic carbon sequestration in sediments and the deep sea from 73 to 866 Tg C yr−1, representing between 3 % and 1∕3 of oceanic CO2 uptake. Up to 1∕2 of this carbon sequestration occurs in sink reservoirs (sediments or the deep sea) beyond these habitats. The organic carbon exported that does not reach depositional sites subsidizes the metabolism of heterotrophic organisms. In addition to a significant contribution to organic carbon production and sequestration, vegetated coastal habitats contribute as much to carbonate accumulation as coral reefs do. While globally relevant, the magnitude of global carbon fluxes supported by salt-marsh, mangrove, seagrass and macroalgal habitats is declining due to rapid habitat loss, contributing to loss of CO2 sequestration, storage capacity and carbon subsidies. Incorporating the carbon fluxes' vegetated coastal habitats' support into depictions of the carbon budget of the global ocean and its perturbations will improve current representations of the carbon budget of the global ocean.

scholarly journals Total carbon analysis may overestimate organic carbon content of fresh waters in the presence of high dissolved inorganic carbon

2010 ◽  
Vol 8 (5) ◽  
pp. 196-201 ◽  
Author(s):  
Stuart Findlay ◽  
William H. McDowell ◽  
David Fischer ◽  
Michael L. Pace ◽  
Nina Caraco ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Carbon ◽  
Organic Carbon Content ◽  
Fresh Waters ◽  
Carbon Analysis

scholarly journals Extended evaluation of quality of swimming pool water - importance of selected pollutant fractions

2018 ◽  
Vol 44 ◽  
pp. 00098
Author(s):  
Edyta Łaskawiec ◽  
Mariusz Dudziak ◽  
Joanna Wyczarska-Kokot
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Main Parameter ◽  
Inorganic Carbon ◽  
Separation Process ◽  
Total Carbon ◽  
Distribution Characteristics ◽  
Fraction Distribution ◽  
Swimming Pool Water

The authors of the study attempted to determine the fraction of selected impurities in the filter backwash water from the pool circuit (hot tub). Ultrafiltration membranes were used for the separation process. The main parameter informing about the content of impurities in a given fraction was total carbon (including the total organic carbon). In the studies, fractions with the following sizes of > 200 kDa, 50–200 kDa, < 50 kDa were separated. The fraction distribution in > 5 kDa and < 5kDa was also analyzed. The percentage content of inorganic carbon and total organic carbon changed depending on the ultrafiltration membrane with different distribution characteristics. The concentration of total organic carbon decreased gradually with a decrease in the MWCO value of the membrane. On the basis of the total carbon value, it was found that the tested washings contained: 30.40 wt.% of > 200 kDa fraction, 55.62 wt.% of fraction in the range of 50–200 kDa and 13.98 wt.% of fraction < 50kDa.

scholarly journals Lateral Export of Dissolved Inorganic and Organic Carbon from a Small Mangrove Estuary with Tidal Fluctuation

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1041 ◽  
Author(s):  
Toshiyuki Ohtsuka ◽  
Takeo Onishi ◽  
Shinpei Yoshitake ◽  
Mitsutoshi Tomotsune ◽  
Morimaru Kida ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Budget ◽  
Water Exchange ◽  
Inorganic Carbon ◽  
River Mouth ◽  
Mangrove Area ◽  
Ecosystem Carbon ◽  
Mangrove Estuary ◽  
Methodological Difficulty ◽  
Mangrove Ecosystems

The significance of aquatic lateral carbon (C) export in mangrove ecosystems highlights the extensive contribution of aquatic pathways to the net ecosystem carbon budget. However, few studies have investigated lateral fluxes of dissolved organic carbon (DOC) and inorganic carbon (DIC), partly due to methodological difficulty. Therefore, we evaluated area-based lateral C fluxes in a small mangrove estuary that only had one exit for water exchange to the coast. We sampled water from the mouth of the creek and integrated discharge and consecutive concentration of mangrove-derived C (ΔC). Then, we estimated the area-normalized C fluxes based on the inundated mangrove area. DIC and DOC concentrations at the river mouth increased during ebb tide during both summer and winter. We quantified the ΔC in the estuary using a two-component conservative mixing model of freshwater and seawater. DIC and DOC proportions of ΔC concentrations at the river mouth during ebb tide was between 34% and 56% in the winter and 26% and 42% in the summer, respectively. DIC and DOC fluxes from the estuary were estimated to be 1.36 g C m−2 d−1 and 0.20 g C m−2 d−1 in the winter and 3.35 g C m−2 d−1 and 0.86 g C m−2 d−1 in the summer, respectively. Based on our method, daily fluxes are mangrove area-based DIC and DOC lateral exports that can be directly incorporated into the mangrove carbon budget.

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