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| Titel |
Predicting decadal trends and transient responses of radiocarbon storage and fluxes in a temperate forest soil |
| VerfasserIn |
C. A. Sierra, S. E. Trumbore, E. A. Davidson, S. D. Frey, K. E. Savage, F. M. Hopkins |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066017
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| Zusammenfassung |
| Representing the response of soil carbon dynamics to global environmental change requires
the incorporation of multiple tools in the development of predictive models. An important
tool to construct and test models is the incorporation of bomb radiocarbon in soil organic
matter during the past decades. In this manuscript, we combined radiocarbon data and a
previously developed empirical model to explore decade-scale soil carbon dynamics in a
temperate forest ecosystem at the Harvard Forest, Massachusetts, USA. We evaluated the
contribution of different soil C fractions to both total soil CO2 efflux and microbially-respired
C. We tested the performance of the model based on measurable soil organic matter fractions
against a decade of radiocarbon measurements. The model was then challenged with
radiocarbon measurements from a warming and N addition experiment to test multiple
hypotheses about the different response of soil C fractions to the experimental manipulations.
Our results showed that the empirical model satisfactorily predicts the trends of
radiocarbon in litter, density fractions, and respired CO2 observed over a decade in the
soils not subjected to manipulation. However, the model, modified with prescribed
relationships for temperature and decomposition rates, predicted most but not all the
observations from the field experiment where soil temperatures and nitrogen levels were
increased, suggesting that a larger degree of complexity and mechanistic relations need
to be added to the model to predict short-term responses and transient dynamics. |
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