Combining biomarker with stable isotope analyses for assessing the transformation and turnover of soil organic matter

By W. Amelung, S. Brodowski, A. Sandhage-Hofmann, R. Bol. 2008

385 citations recorded by the source corpus.

Soil organic matter (SOM) consists of a vast range of biomolecules, but their individual contribution to the biogeochemical cycling of nutrients and CO2 release has eluded researchers. Here, we review the current knowledge on combining biomarker with stable isotope analyses for identifying the mechanisms and rates of SOM genesis and transformation. After an overview of the major biomarkers that are used for identifying decomposer communities and the origin of SOM far beyond microbial life cycles, we reexplain the principles and potentials of applying artificial and natural stable isotope labeling techniques in soil research. Major focus is finally laid on the quantitative evaluation of the published compound-specific stable isotope data of soils to characterize the niches and activity of soil microorganisms as well as their role in controlling the short-to long-term fate of SOM. Our literature research suggested that fungi appear to feed mainly on fresh plant material, whereas gram-positive bacteria also consume both fresh and older SOM. The newly synthesized structures have apparent mean residence time (MRT) of 1–80 years, while refractory plant-derived biomarkers may even dissipate faster. In no case did we find evidences for inert soil C. However, MRT was not constant but increased with increasing time after C3/C4 vegetation change. It is concluded that calculated MRTs from C3/C4 vegetation changes are currently underestimated, because,there is also a the formation of stable C4-derived C pools that did not reach steady-state equilibrium within few decades.

Subfields: Ecology, Soil Science

View Paper: https://www.semanticscholar.org/paper/d8c05149467503d0f5893a33388a6b8b06d2057e

How researchers see this paper

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In Ecology

1. Y. Kuzyakov
2. E. Blagodatskaya
3. A. Gunina
4. C. Liang
5. M. Dippold
6. R. Joergensen
7. R. Benner
8. B. Jansen

In Soil Science

1. Y. Kuzyakov
2. E. Blagodatskaya
3. A. Gunina
4. M. Dippold
5. B. Glaser
6. R. Joergensen
7. C. Liang
8. P. Mäder

Citations in the corpus

• 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, neutral): “…in soils, including n-alkanes and related compounds, have rather fast turnover times (e.g. Rethemeyer et al., 2004),n-alkanes are generally slightly more recalcitrant, showing turnover times on the order of decades (ca. 8 to 60 years in arable soils, Amelung et al., 2008 and references therein).”
• The roles of microorganisms in litter decomposition and soil formation (2014, background): “Most GalN in soil is thought to be of bacterial origin (Parsons 1981; Amelung 2001; Amelung et al. 2008), and results from the present study are consistent with a large contribution of GalN from bacteria.”
• Quantitative assessment of microbial necromass contribution to soil organic matter (2019, background): “…but instead in their native bioaggregate association, since the assessment with pure compounds results in severe under‐ estimations of half‐lives (Amelung et al., 2008; Carini et al., 2016; Hu, Zheng, Zhang, Noll, & Wanek, 2018) due to a much better availability to microbial degradation…”
• Active microorganisms in soil: Critical review of estimation criteria and approaches (2013, background): “The fate of 13C from labeled plant residues, rhizodeposits or specific organic compounds added to soil can be traced in DNA/RNA, PLFA, and other biomarkers to identify the microorganisms metabolizing the added substrates (Glaser, 2005; Amelung et al., 2008).”
• Turnover of microbial groups and cell components in soil: 13 C analysis of cellular biomarkers (2017, methodology): “The PLFAs turnover times estimated in the field conditions using a C 3 /C 4 vegetation change (Amelung et al., 2008; Glaser, 2005) or 14 C dating (Rethemeyer et al., 2005) were between 1 and 80 years.”
• Opportunities and limitations related to the application of plant-derived lipid molecular proxies in soil science (2017, background): “The turnover rates of molecular proxies not only vary between different compartments, but may also vary within the same compartment between and even within different (classes of) molecules (Dinel et al., 1990; Bull et al., 2000; Amelung et al., 2008).”
• Long-term effects of organic farming on fungal and bacterial residues in relation to microbial energy metabolism (2010, background): “Amino sugars are the most important indicators for the presence of microbial residues in soil (Amelung et al. 2008) and contribute significant amounts of between 5% and 12% to soil organic N (Stevenson 1983; Amelung 2001).”