scholarly journals Importance of extracellular organic carbon production in the total primary production by tidal-flat diatoms in comparison to phytoplankton

1999 ◽  
Vol 190 ◽  
pp. 289-295 ◽  
Author(s):  
N Goto ◽  
T Kawamura ◽  
O Mitamura ◽  
H Terai
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Tidal Flat ◽  
Carbon Production ◽  
Total Primary Production

scholarly journals Rapid carbon cycling in the oligotrophic ocean

2011 ◽  
Vol 8 (6) ◽  
pp. 11661-11687 ◽  
Author(s):  
C. M. Duarte ◽  
S. Agustí
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Time Scales ◽  
Net Primary Production ◽  
Cell Lysis ◽  
Carbon Flow ◽  
Phytoplankton Production ◽  
Carbon Production ◽  
Phytoplankton Cell ◽  
Net Phytoplankton

Abstract. The dynamics of organic carbon production, release and bacterial use was examined across a range of communities spanning from highly oligotrophic ones in the Subtropical Atlantic Ocean, mesotrophic ones in the Mediterranean Sea and productive ones in the Northern African upwelling and the Southern Ocean. A comparative analysis of experiments examining total and particulate organic carbon production across a range of time scales (15 min to 24 h) for 20 communities with contrasting phytoplankton cell status, as assessed by cell lysis rates, and the use of a simple inverse model was used to resolve patterns of carbon flow in the microbial food web. Communities in productive ocean waters accumulated organic carbon over hourly time scales, whereas only a small fraction of net primary production accumulated in communities from oligotrophic waters. These communities supported high phytoplankton cell lysis rates leading to a rapid flux of organic carbon to bacteria, which had high affinity for phytoplankton-derived carbon, much of which was rapidly respired. Conventional assessments of primary production in the oligotrophic ocean severely underestimate net phytoplankton production, as carbon flow in microbial communities from oligotrophic ocean waters occurs within short (minutes) time scales. This explains difficulties to reconcile estimates of primary production with independent estimates of carbon use by bacteria in oligotrophic marine ecosystems.

scholarly journals Decadal variations of total organic carbon production in the inner-shelf of the South China Sea and East China Sea

2019 ◽  
Vol 11 (1) ◽  
pp. 1061-1070
Author(s):  
Rediat Abate ◽  
Changping Chen ◽  
Junrong Liang ◽  
Lin Sun ◽  
Xuesong Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
South China Sea ◽  
Primary Production ◽  
Total Organic Carbon ◽  
East China Sea ◽  
South China ◽  
Inner Shelf ◽  
Leizhou Peninsula ◽  
China Sea ◽  
Carbon Production

Abstract Organic carbon content is one of the major proxies of aquatic primary production and implication of environmental changes. However, there is a scarcity of information regarding the decadal variation of organic carbon production in inner-shelf of South China Sea (SCS) and East China Sea (ECS). To bridge this gap of information two sediment cores were collected from the inner shelf of SCS (Leizhou Peninsula) and ECS. Then, Total Organic Carbon (TOC), Total Inorganic Carbon (TIC) and Total Nitrogen (TN) content were examined. The TOC content in the Leizhou Peninsula averaged 0.56% and varied from 0.35% to 0.81%. At decadal time scale, the TOC content of Leizhou Peninsula erratically increased in the last century, and it distinctly peaked after 1990’s. This is related to increased primary production due to the increased input of anthropogenic nutrients and rainfall level. The TOC content of the inner shelf of ECS averaged 0.5% and varied narrowly from 0.46% to 0.53%. The TOC:TN ratio of ECS averaged 5.65 and varied from 4.42 to 7.85, indicating there is high degree of organic matter degradations. The TN:TP ratios were below 10 for the periods before late-1990’s, indicating that there had been a potential nitrogen limitation in the inner shelf of ECS. Generally, this study showed that the TOC and TIC of ECS and SCS inner-shelf had undergone substantial changes in the last century.

scholarly journals High Rates of Ecosytem Metabolism in Five Western Rivers

2011 ◽  
Vol 33 ◽  
pp. 115-118
Author(s):  
Robert Hall ◽  
Jennifer Tank ◽  
Michelle Baker ◽  
Emma Rosi-Marshall ◽  
Michael Grace ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Carbon Cycling ◽  
Carbon Balance ◽  
Carbon Fixation ◽  
Higher Plants ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Total Rate ◽  
Global Carbon

Primary production and respiration are core functions of river ecosystems that in part determine the carbon balance. Gross primary production (GPP) is the total rate of carbon fixation by autotrophs such as algae and higher plants and is equivalent to photosynthesis. Ecosystem respiration (ER) measures rate at which organic carbon is mineralized to CO2 by all organisms in an ecosystem. Together these fluxes can indicate the base of the food web to support animal production (Marcarelli et al. 2011), can predict the cycling of other elements (Hall and Tank 2003), and can link ecosystems to global carbon cycling (Cole et al. 2007).

scholarly journals CHARACTERISTICS OF RICE SOILS FROM THE TIDAL FLAT AREAS OF MUSI BANYUASIN, SOUTH SUMATRA

2016 ◽  
Vol 2 (1) ◽  
pp. 10 ◽  
Author(s):  
B.H. Prasetyo ◽  
S. Suping ◽  
Subagyo H. ◽  
Mujiono Mujiono ◽  
H. Suhardjo
Keyword(s):  
Organic Carbon ◽  
Tidal Flat ◽  
Amorphous Materials ◽  
Mineral Soil ◽  
Soil Samples ◽  
Moisture Regime ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Specific Chemical ◽  
Very High

Tidal flats in the Musi Banyuasin region that cover more than 200,000 ha are the largest area for agricultural development in South Sumatra Province. Only about a half of this has been used for tidal swamp rice fields, therefore, the other half needs to be developed. To obtain a better understanding of their properties for appropriate soil management, soil characteristics of the area need to be studied. To characterize the soil, thirty-four soil samples from seven soil profiles were analyzed for their chemical and mineralogical composition at the laboratories of the Center for Soil and Agroclimate Research and Development. The results indicate that soils from the tidal flat areas have an aquic soil moisture regime, the upper parts of the soils are mostly ripe, and most of the pedons show the presence of sulfidic materials below 65 cm of the mineral soil surface. The soils are classified as Sulfic Endoaquept (P1, P2), Histic Sulfaquent (P3), Typic Sulfaquept (P4), Fluvaquentic Endoaquept (P5), and Sulfic Hydraquent (P6, P7). Mineral composition of the sand fraction is dominated by quartz, while the clay minerals consist of predominantly kaolinite, mixed with small amount of smectite, illite, quartz, and crystoballite. Organic carbon content is high to very high, potential phosphate content of most pedons ranges from very low to medium, while potential potassium content varies from very low to medium in the upper layers and medium to very high in the bottom layers. Phosphate retention of topsoil sample varies from 56 to 97%, and is positively correlated (r2 = 0.73) with aluminum from amorphous materials. Exchangeable cations are dominated by Mg cation, and in all pedons cation exchange capacity values are medium to very high, and seem to be influenced by organic carbon. Specific chemical properties, particularly soil pH and content of exchangeable aluminum exhibit a significant change about 1-2 months after soil samples were taken from the field. Theoretically, interaction between good water management and fertilizer application are among the choices of management to make these soils productive.

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.

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