Details
| Original language | English |
|---|---|
| Pages (from-to) | 35-43 |
| Number of pages | 9 |
| Journal | Journal of Plant Nutrition and Soil Science |
| Volume | 185 |
| Issue number | 1 |
| Early online date | 17 Oct 2021 |
| Publication status | Published - 8 Feb 2022 |
Abstract
Background: Soils are important carbon (C) sinks or sources and thus of utmost importance for global carbon cycling. Particularly, subsoils are considered to have a high potential for additional C storage due to mineral surfaces still available for sorptive stabilization. Aims: Little information exists about the extent to which additional litter-derived C is transferred to and stabilized in subsoils. This study aimed at evaluating the role of litter-derived dissolved organic matter (DOM) inputs for the formation of stable mineral-associated C in subsoils. Methods: We carried out a multiple-method approach including field labeling with 13C-enriched litter, exposure of 13C-loaded reactive minerals to top- and subsoils, and laboratory sorption experiments. Results: For temperate forest soils, we found that the laboratory-based C sink capacity of subsoils is unlikely to be reached under field conditions. Surface C inputs via litter leachates are little conducive to the subsoil C pool. Only 0.5% of litter-derived C entered the subsoil as DOM within nearly 2 years and most of the recently sorbed C is prone to fast microbial mineralization rather than long-term mineral retention. Desorption to the soil solution and an adapted microbial community re-mobilize organic matter in subsoils faster than considered so far. Conclusions: We conclude that the factors controlling the current mineral retention and stabilization of C within temperate forest subsoils will likewise limit additional C uptake. Thus, in contrast to their widely debated potential to accrue more C, the role of forest subsoils as future C sink is likely overestimated and needs further reconsideration.
Keywords
- carbon cycling, climate change mitigation, microbial community composition, mineral-associated organic carbon
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Soil Science
- Agricultural and Biological Sciences(all)
- Plant Science
Sustainable Development Goals
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In: Journal of Plant Nutrition and Soil Science, Vol. 185, No. 1, 08.02.2022, p. 35-43.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Biogeochemical limitations of carbon stabilization in forest subsoils
AU - Liebmann, Patrick
AU - Mikutta, Robert
AU - Kalbitz, Karsten
AU - Wordell-Dietrich, Patrick
AU - Leinemann, Timo
AU - Preusser, Sebastian
AU - Mewes, Ole
AU - Perrin, Eike
AU - Bachmann, Jörg
AU - Don, Axel
AU - Kandeler, Ellen
AU - Marschner, Bernd
AU - Schaarschmidt, Frank
AU - Guggenberger, Georg
N1 - Funding Information: We thank Martin Volkmann, Hanna B?hme, Susanne K. Woche, and Frank Hegewald for their help in the field, and Heike Steffen and Anne Kathrin Herwig for sample preparations. We thank Manuela Unger for the DO13C measurements and Heike Haslwimmer for molecular analyses (qPCR data). Carsten Beyer is acknowledged for the analysis of the DOM composition. Financial support for this work was provided by the Deutsche Forschungsgemeinschaft (DFG) within the framework of the DFG Research Unit 1806 ?The forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)? and the individual grants GU 406/28?1,2, KA 1737/15?2, MI 1377/10?2, DO 1734/4?2, KA 1590/11?2, BA1359/13?2, BA1359/14?2, and MA 1830/14?2. Open access funding enabled and organized by Projekt DEAL.
PY - 2022/2/8
Y1 - 2022/2/8
N2 - Background: Soils are important carbon (C) sinks or sources and thus of utmost importance for global carbon cycling. Particularly, subsoils are considered to have a high potential for additional C storage due to mineral surfaces still available for sorptive stabilization. Aims: Little information exists about the extent to which additional litter-derived C is transferred to and stabilized in subsoils. This study aimed at evaluating the role of litter-derived dissolved organic matter (DOM) inputs for the formation of stable mineral-associated C in subsoils. Methods: We carried out a multiple-method approach including field labeling with 13C-enriched litter, exposure of 13C-loaded reactive minerals to top- and subsoils, and laboratory sorption experiments. Results: For temperate forest soils, we found that the laboratory-based C sink capacity of subsoils is unlikely to be reached under field conditions. Surface C inputs via litter leachates are little conducive to the subsoil C pool. Only 0.5% of litter-derived C entered the subsoil as DOM within nearly 2 years and most of the recently sorbed C is prone to fast microbial mineralization rather than long-term mineral retention. Desorption to the soil solution and an adapted microbial community re-mobilize organic matter in subsoils faster than considered so far. Conclusions: We conclude that the factors controlling the current mineral retention and stabilization of C within temperate forest subsoils will likewise limit additional C uptake. Thus, in contrast to their widely debated potential to accrue more C, the role of forest subsoils as future C sink is likely overestimated and needs further reconsideration.
AB - Background: Soils are important carbon (C) sinks or sources and thus of utmost importance for global carbon cycling. Particularly, subsoils are considered to have a high potential for additional C storage due to mineral surfaces still available for sorptive stabilization. Aims: Little information exists about the extent to which additional litter-derived C is transferred to and stabilized in subsoils. This study aimed at evaluating the role of litter-derived dissolved organic matter (DOM) inputs for the formation of stable mineral-associated C in subsoils. Methods: We carried out a multiple-method approach including field labeling with 13C-enriched litter, exposure of 13C-loaded reactive minerals to top- and subsoils, and laboratory sorption experiments. Results: For temperate forest soils, we found that the laboratory-based C sink capacity of subsoils is unlikely to be reached under field conditions. Surface C inputs via litter leachates are little conducive to the subsoil C pool. Only 0.5% of litter-derived C entered the subsoil as DOM within nearly 2 years and most of the recently sorbed C is prone to fast microbial mineralization rather than long-term mineral retention. Desorption to the soil solution and an adapted microbial community re-mobilize organic matter in subsoils faster than considered so far. Conclusions: We conclude that the factors controlling the current mineral retention and stabilization of C within temperate forest subsoils will likewise limit additional C uptake. Thus, in contrast to their widely debated potential to accrue more C, the role of forest subsoils as future C sink is likely overestimated and needs further reconsideration.
KW - carbon cycling
KW - climate change mitigation
KW - microbial community composition
KW - mineral-associated organic carbon
UR - http://www.scopus.com/inward/record.url?scp=85117920978&partnerID=8YFLogxK
U2 - 10.1002/jpln.202100295
DO - 10.1002/jpln.202100295
M3 - Article
AN - SCOPUS:85117920978
VL - 185
SP - 35
EP - 43
JO - Journal of Plant Nutrition and Soil Science
JF - Journal of Plant Nutrition and Soil Science
SN - 1436-8730
IS - 1
ER -