The soil microbial carbon pump: From conceptual insights to empirical assessments

2020 ◽  
Vol 26 (11) ◽  
pp. 6032-6039
Author(s):  
Xuefeng Zhu ◽  
Randall D. Jackson ◽  
Evan H. DeLucia ◽  
James M. Tiedje ◽  
Chao Liang
Keyword(s):  
Soil Microbial ◽  
Carbon Pump ◽  
Microbial Carbon ◽  
Microbial Carbon Pump

scholarly journals An implementation strategy to quantify the marine microbial carbon pump and its sensitivity to global change

2018 ◽  
Vol 5 (4) ◽  
pp. 474-480 ◽  
Author(s):  
Carol Robinson ◽  
Douglas Wallace ◽  
Jung-Ho Hyun ◽  
Luca Polimene ◽  
Ronald Benner ◽  
...  
Keyword(s):  
Global Change ◽  
Implementation Strategy ◽  
Carbon Pump ◽  
Microbial Carbon ◽  
Microbial Carbon Pump

scholarly journals Perspectives on the microbial carbon pump with special reference to microbial respiration and ecosystem efficiency in large estuarine systems

2014 ◽  
Vol 11 (14) ◽  
pp. 3887-3898 ◽  
Author(s):  
H. Dang ◽  
N. Jiao
Keyword(s):  
Dissolved Oxygen ◽  
Carbon Fixation ◽  
Negative Impact ◽  
Energy Transduction ◽  
Metabolic Energy ◽  
Transduction Efficiency ◽  
Estuarine Ecosystems ◽  
Carbon Pump ◽  
Microbial Carbon ◽  
Microbial Carbon Pump

Abstract. Although respiration-based oxidation of reduced carbon releases CO2 into the environment, it provides an ecosystem with the metabolic energy for essential biogeochemical processes, including the newly proposed microbial carbon pump (MCP). The efficiency of MCP in heterotrophic microorganisms is related to the mechanisms of energy transduction employed and hence is related to the form of respiration utilized. Anaerobic organisms typically have lower efficiencies of energy transduction and hence lower efficiencies of energy-dependent carbon transformation. This leads to a lower MCP efficiency on a per-cell basis. Substantial input of terrigenous nutrients and organic matter into estuarine ecosystems typically results in elevated heterotrophic respiration that rapidly consumes dissolved oxygen, potentially producing hypoxic and anoxic zones in the water column. The lowered availability of dissolved oxygen and the excessive supply of nutrients such as nitrate from river discharge lead to enhanced anaerobic respiration processes such as denitrification and dissimilatory nitrate reduction to ammonium. Thus, some nutrients may be consumed through anaerobic heterotrophs, instead of being utilized by phytoplankton for autotrophic carbon fixation. In this manner, eutrophied estuarine ecosystems become largely fueled by anaerobic respiratory pathways and their efficiency is less due to lowered ecosystem productivity when compared to healthy and balanced estuarine ecosystems. This situation may have a negative impact on the ecological function and efficiency of the MCP which depends on the supply of both organic carbon and metabolic energy. This review presents our current understanding of the MCP mechanisms from the view point of ecosystem energy transduction efficiency, which has not been discussed in previous literature.

scholarly journals THE MICROBIAL CARBON PUMP: EMERGING ISSUES WORKSHOP REPORT

2011 ◽  
Vol 20 (2) ◽  
pp. 37-38
Author(s):  
Nianzhi Jiao ◽  
Carol Robinson ◽  
Gerhard Kattner
Keyword(s):  
Workshop Report ◽  
Carbon Pump ◽  
Emerging Issues ◽  
Microbial Carbon ◽  
Microbial Carbon Pump

Modelling the Microbial Carbon Pump in a changing ocean: current state and future directions

2020 ◽  
Author(s):  
Luca Polimene ◽  
Sevrine Sailley ◽  
Darren Clark ◽  
Susan Kimmance
Keyword(s):  
Numerical Models ◽  
Process Models ◽  
Bacterial Degradation ◽  
Ocean Current ◽  
Future Research ◽  
Adequate Model ◽  
Carbon Pump ◽  
Microbial Carbon ◽  
Microbial Carbon Pump ◽  
Residual Product

<p>Circa 624 gigatons of carbon are locked in the ocean as dissolved organic matter (DOM), an amount comparable with the entire CO<sub>2</sub> content of the extant atmosphere. This DOM is operationally defined as refractory, meaning that it is resistant to bacterial degradation and persists in the ocean for millennia. Refractory DOM is considered primarily a residual product of heterotrophic bacterial activity after the bacterial consumption of more labile (i.e. easily degradable) DOM produced by marine autotrophs through photosynthesis. The process through which bacteria form refractory-DOM is termed the ‘Microbial Carbon Pump’ (MCP). Abiotic degradation (e.g. photo-degradation) is thought to balance refractory DOM production, thus maintaining its current pool in steady state. However, recent studies suggest that changes in surface ocean inorganic nutrient availability, due to climate change related increases in thermal stratification, could modify MCP activity, increasing refractory-DOM production with respect to its consumption. Marine bacteria thus have the potential to mitigate increases in atmospheric CO<sub>2</sub> by shunting more photosynthesised carbon into refractory-DOM. This hypothesis can only be tested by including the MCP in numerical models used for climate prediction. However, the lack of mechanistic understanding of the process (due, in turn, to the lack of experimental data) has hitherto prevented the development of adequate model formulations. In this talk, I will discuss the potential (and limitations) of existing process models to simulate (at least partially) the MCP and highlight future research directions (and related challenges) to develop new model formulations describing this process.</p>

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