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| Titel |
Representing life in the Earth system with soil microbial functional traits in the MIMICS model |
| VerfasserIn |
W. R. Wieder, A. S. Grandy, C. M. Kallenbach, P. G. Taylor, G. B. Bonan |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1991-959X
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 8, no. 6 ; Nr. 8, no. 6 (2015-06-17), S.1789-1808 |
| Datensatznummer |
250116409
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| Publikation (Nr.) |
 copernicus.org/gmd-8-1789-2015.pdf |
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| Zusammenfassung |
| Projecting biogeochemical responses to global environmental change requires
multi-scaled perspectives that consider organismal diversity, ecosystem
processes, and global fluxes. However, microbes, the drivers of soil organic
matter decomposition and stabilization, remain notably absent from models
used to project carbon (C) cycle–climate feedbacks. We used a microbial
trait-based soil C model with two physiologically distinct
microbial communities, and evaluate how this model represents soil C storage
and response to perturbations. Drawing from the application of functional
traits used to model other ecosystems, we incorporate copiotrophic and
oligotrophic microbial functional groups in the MIcrobial-MIneral Carbon
Stabilization (MIMICS) model; these functional groups are akin to "gleaner"
vs. "opportunist" plankton in the ocean, or r- vs. K-strategists in plant and
animal communities. Here we compare MIMICS to a conventional soil C model,
DAYCENT (the daily time-step version of the CENTURY model), in cross-site comparisons of nitrogen (N) enrichment effects on
soil C dynamics. MIMICS more accurately simulates C responses to N
enrichment; moreover, it raises important hypotheses involving the roles of
substrate availability, community-level enzyme induction, and microbial
physiological responses in explaining various soil biogeochemical responses
to N enrichment. In global-scale analyses, we show that MIMICS projects much
slower rates of soil C accumulation than a conventional soil biogeochemistry
in response to increasing C inputs with elevated carbon dioxide (CO2) – a
finding that would reduce the size of the land C sink estimated by the Earth
system. Our findings illustrate that tradeoffs between theory and utility
can be overcome to develop soil biogeochemistry models that evaluate and
advance our theoretical understanding of microbial dynamics and soil
biogeochemical responses to environmental change. |
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