scholarly journals Short organic carbon turnover time and narrow 14 C age spectra in early Holocene wetland paleosols

2017 ◽  
Vol 18 (1) ◽  
pp. 142-155 ◽  
Author(s):  
Lael Vetter ◽  
Brad E. Rosenheim ◽  
Alvaro Fernandez ◽  
Torbjörn E. Törnqvist
Keyword(s):  
Organic Carbon ◽  
Turnover Time ◽  
Early Holocene ◽  
Carbon Turnover

Organic carbon turnover time in deep-sea benthos

1990 ◽  
Vol 24 (1-4) ◽  
pp. 141-160 ◽  
Author(s):  
Gilbert T Rowe ◽  
Myriam Sibuet ◽  
Jody Deming ◽  
John Tietjen ◽  
Alexis Khripounoff
Keyword(s):  
Organic Carbon ◽  
Deep Sea ◽  
Turnover Time ◽  
Carbon Turnover

scholarly journals Fire-derived organic carbon turnover in soils on a centennial scale

2011 ◽  
Vol 8 (6) ◽  
pp. 12179-12195
Author(s):  
N. Singh ◽  
S. Abiven ◽  
M. S. Torn ◽  
M. W. I. Schmidt
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Pyrolysis Temperature ◽  
Plant Biomass ◽  
Meta Analysis ◽  
Turnover Time ◽  
Carbon Turnover ◽  
Biomass Pyrolysis ◽  
Pyrogenic Carbon

Abstract. Pyrogenic Carbon (PyC), the residue of an incomplete combustion of plant biomass, is considered as a carbon (C) sink due to its assumed stability in soil. Our meta-analysis of studies on PyC degradation challenges the assumption that PyC persist in soil for several thousand years. The turnover time for PyC estimated here ranges from decadal to centennial time scales, and is not slower than decomposition of bulk Soil Organic Matter (SOM) and differs with initial biomass, pyrolysis temperature and climate. Thus, using PyC as a strategy for offsetting carbon emissions requires caution and further research.

Plant carbon inputs through shoot, root, and mycorrhizal pathways affect soil organic carbon turnover differently

2021 ◽  
pp. 108322
Author(s):  
Junsheng Huang ◽  
Weixing Liu ◽  
Sen Yang ◽  
Lu Yang ◽  
Ziyang Peng ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Turnover

Subsoil organic carbon turnover is dominantly controlled by soil properties in grasslands across China

2021 ◽  
Author(s):  
Yuehong Shi ◽  
Xiaolu Tang ◽  
Peng Yu ◽  
Li Xu ◽  
Guo Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Properties ◽  
Soil Carbon ◽  
Carbon Turnover ◽  
Area Index ◽  
Important Indicator ◽  
Environmental Controls ◽  
Biogeochemical Models ◽  
Soc Stock

<p>Soil carbon turnover time (τ, year) is an important indicator of soil carbon stability, and a major factor in determining soil carbon sequestration capacity. Many studies investigated τ in the topsoil or the first meter underground, however, little is known about subsoil τ (0.2 – 1.0 m) and its environmental drivers, while world subsoils below 0.2 m accounts for the majority of total soil organic carbon (SOC) stock and may be as sensitive as that of the topsoil to climate change. We used the observations from the published literatures to estimate subsoil τ (the ratio of SOC stock to net primary productivity) in grasslands across China and employed regression analysis to detect the environmental controls on subsoil τ. Finally, structural equation modelling (SEM) was applied to identify the dominant environmental driver (including climate, vegetation and soil). Results showed that subsoil τ varied greatly from 5.52 to 702.17 years, and the mean (± standard deviation) subsoil τ was 118.5 ± 97.8 years. Subsoil τ varied significantly among different grassland types that it was 164.0 ± 112.0 years for alpine meadow, 107.0 ± 47.9 years for alpine steppe, 177.0 ± 143.0 years for temperate desert steppe, 96.6 ± 88.7 years for temperate meadow steppe, 101.0 ± 75.9 years for temperate typical steppe. Subsoil τ significantly and negatively correlated (p < 0.05) with vegetation index, leaf area index and gross primary production, highlighting the importance of vegetation on τ. Mean annual temperature (MAT) and precipitation (MAP) had a negative impact on subsoil τ, indicating a faster turnover of soil carbon with the increasing of MAT or MAP under ongoing climate change. SEM showed that soil properties, such as soil bulk density, cation exchange capacity and soil silt, were the most important variables driving subsoil τ, challenging our current understanding of climatic drivers (MAT and MAP) controlling on topsoil τ, further providing new evidence that different mechanisms control topsoil and subsoil τ. These conclusions demonstrated that different environmental controls should be considered for reliable prediction of soil carbon dynamics in the top and subsoils in biogeochemical models or earth system models at regional or global scales.</p>

scholarly journals Carbon isotopic composition of branched tetraether membrane lipids in soils suggest a rapid turnover and a heterotrophic life style of their source organism(s)

2010 ◽  
Vol 7 (9) ◽  
pp. 2959-2973 ◽  
Author(s):  
J. W. H. Weijers ◽  
G. L. B. Wiesenberg ◽  
R. Bol ◽  
E. C. Hopmans ◽  
R. D. Pancost
Keyword(s):  
Organic Carbon ◽  
Isotopic Composition ◽  
Life Style ◽  
Membrane Lipids ◽  
Carbon Isotopic Composition ◽  
Turnover Time ◽  
Arable Soils ◽  
Higher Plant ◽  
Δ13c Values ◽  
Carbon Isotopic

Abstract. Branched Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are membrane spanning lipids synthesised by as yet unknown bacteria that thrive in soils and peat. In order to obtain more information on their ecological niche, the stable carbon isotopic composition of branched GDGT-derived alkanes, obtained upon ether bond cleavage, has been determined in a peat and various soils, i.e. forest, grassland and cropland, covered by various vegetation types, i.e., C3- vs. C4-plant type. These δ13C values are compared with those of bulk organic matter and higher plant derived n-alkanes from the same soils. With average δ13C values of −28‰, branched GDGTs in C3 soils are only slightly depleted (ca. 1‰) relative to bulk organic carbon and on average 8.5‰ enriched relative to plant wax-derived long-chain n-alkanes ( nC29–nC33). In an Australian soil dominantly covered with C4 type vegetation, the branched GDGTs have a δ13C value of −18‰, clearly higher than observed in soils with C3 type vegetation. As with C3 vegetated soils, branched GDGT δ13C values are slightly depleted (1‰) relative to bulk organic carbon and enriched (ca. 5‰) relative to n-alkanes in this soil. The δ13C values of branched GDGT lipids being similar to bulk organic carbon and their co-variation with those of bulk organic carbon and plant waxes, suggest a heterotrophic life style and assimilation of relatively heavy and likely labile substrates for the as yet unknown soil bacteria that synthesise the branched GDGT lipids. However, a chemoautotrophic lifestyle, i.e. consuming respired CO2, could not be fully excluded based on these data alone. Based on a natural labelling experiment of a C3/C4 crop change introduced on one of the soils 23 years before sampling and based on a free-air CO2 enrichment experiment with labelled CO2 on another soil, a turnover time of ca. 18 years has been estimated for branched GDGTs in these arable soils.

A new model for soil organic carbon turnover using bomb carbon

2004 ◽  
Vol 18 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Volker Hahn ◽  
Nina Buchmann
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Turnover ◽  
New Model

Effects of bacterial lignin peroxidase on organic carbon mineralization in soil, using recombinant Streptomyces strains

1991 ◽  
Vol 37 (4) ◽  
pp. 287-294 ◽  
Author(s):  
Zemin Wang ◽  
Don L. Crawford ◽  
Timothy S. Magnuson ◽  
Bruce H. Bleakley ◽  
Greg Hertel
Keyword(s):  
Organic Carbon ◽  
Lignin Peroxidase ◽  
Turnover Rate ◽  
Carbon Mineralization ◽  
Evolution Rate ◽  
Carbon Turnover ◽  
Wild Type ◽  
Sterile Soil ◽  
Short Term ◽  
Nonsterile Soil

To study the effects of bacterial lignin peroxidase ALip-P3 of Streptomyces viridosporus T7A on the rate of organic carbon turnover in soil, purified lignin peroxidase, with and without addition of H2O2, was added to sterile and nonsterile silt loam soil. Recombinant Streptomyces lividans strains expressing plasmid-encoded ALip-P3 were also inoculated into the soil. Carbon mineralization was monitored by measuring the rate of CO2 evolution from the soil. In sterile soil, lignin peroxidase addition altered carbon turnover, by increasing the CO2 evolution rate above the near-zero rate of sterile, uninoculated soil. H2O2, when added alone, had no effect, and its addition in combination with peroxidase gave results similar to peroxidase alone. This effect was also observed upon addition of lignin peroxidase to sterile soil already inoculated with S. viridosporus T7A. The increases in soil CO2 evolution rates were also observed in experiments using nonsterile soil. However, results showed more variation, and the effect was shorter lived as a result of lessened peroxidase stability. Three recombinant S. lividans strains expressing the ALip-P3 gene in plasmid pIJ702.LP were also inoculated into soil. There were no significant differences in CO2 evolution rates for sterile soil inoculated with recombinants as compared with sterile soil inoculated with wild-type S. lividans strains. However, in nonsterile soil, addition of the recombinants caused a significantly greater increase in the CO2 evolution rate as compared with the corresponding wild types or S. viridosporus T7A. The effect was short lived, lasting about 5 days. Both the recombinant and wild-type Streptomyces survived in the soil for at least 30 days, and pIJ702.LP was stable in the recombinants in soil. Plasmid pIJ702.LP was transformed into three mutants of S. viridosporus T7A that lacked lignin peroxidase. Plasmid-expressing transformants regained the ability to produce lignin peroxidase. The results show that addition of lignin peroxidase ALip-P3 to soil transiently enhanced the short-term rate of carbon mineralization in the soil. The enhancement was lignin peroxidase specific, since substitution of horseradish peroxidase for lignin peroxidase in the soil addition studies resulted in no enhancement of CO2 evolution. In addition, pIJ702.LP-expressing S. lividans strains also caused the effect, which was significant only in nonsterile soil. Thus, lignin peroxidase ALip-P3 appears to affect the short-term turnover rate of lignin-derived organic carbon in soil, and normal, low lignin peroxidase concentrations in soil may limit the initial turnover rate of lignified plant residues in soil. This is the first report of a genetically engineered microorganism having a measurable effect on a biogeochemical cycle in soil. Key words: Streptomyces, recombinant, lignin, peroxidase, soil.

Spatial controls of topsoil and subsoil organic carbon turnover under C3–C4 vegetation change

Geoderma ◽  
2017 ◽  
Vol 303 ◽  
pp. 44-51 ◽  
Author(s):  
H. Schiedung ◽  
N. Tilly ◽  
C. Hütt ◽  
G. Welp ◽  
N. Brüggemann ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Vegetation Change ◽  
Carbon Turnover
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