Rapid loss of complex polymers and pyrogenic carbon in subsoils under whole-soil warming.

Autor: Zosso CU; Department of Geography, University of Zurich, Zurich, Switzerland., Ofiti NOE; Department of Geography, University of Zurich, Zurich, Switzerland., Torn MS; Climate Sciences Department, Lawrence Berkeley National Laboratory, Berkeley, CA USA.; Energy Resources Group, University of California, Berkeley, CA USA., Wiesenberg GLB; Department of Geography, University of Zurich, Zurich, Switzerland., Schmidt MWI; Department of Geography, University of Zurich, Zurich, Switzerland.
Jazyk: angličtina
Zdroj: Nature geoscience [Nat Geosci] 2023; Vol. 16 (4), pp. 344-348. Date of Electronic Publication: 2023 Mar 30.
DOI: 10.1038/s41561-023-01142-1
Abstrakt: Subsoils contain more than half of soil organic carbon (SOC) and are expected to experience rapid warming in the coming decades. Yet our understanding of the stability of this vast carbon pool under global warming is uncertain. In particular, the fate of complex molecular structures (polymers) remains debated. Here we show that 4.5 years of whole-soil warming (+4 °C) resulted in less polymeric SOC (sum of specific polymers contributing to SOC) in the warmed subsoil (20-90 cm) relative to control, with no detectable change in topsoil. Warming stimulated the subsoil loss of lignin phenols (-17 ± 0%) derived from woody plant biomass, hydrolysable lipids cutin and suberin, derived from leaf and woody plant biomass (-28 ± 3%), and pyrogenic carbon (-37 ± 8%) produced during incomplete combustion. Given that these compounds have been proposed for long-term carbon sequestration, it is notable that they were rapidly lost in warmed soils. We conclude that complex polymeric carbon in subsoil is vulnerable to decomposition and propose that molecular structure alone may not protect compounds from degradation under future warming.
Competing Interests: Competing interestsThe authors declare no conflict of interest.
(© The Author(s) 2023.)
Databáze: MEDLINE
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