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| Titel |
Model inversion to improve estimates of autotrophic and heterotrophic soil respiration in winter wheat |
| VerfasserIn |
Nils Prolingheuer, Horst Hardelauf, Harry Vereecken, Jens-Arne Subke, Michael Herbst |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250055266
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| Zusammenfassung |
| Soil respiration is the second largest flux of carbon between ecosystems and the
atmosphere and small changes can lead to a huge impact on the global climate. Modelling
soil respiration helps to improve the understanding of environmental processes.
Especially the separation of soil respiration into its heterotrophic and autotrophic
fraction is a current key challenge. In order to distinguish between heterotrophic and
autotrophic soil respiration we coupled the SOILCO2-RothC model, calculating carbon
turnover, carbon dioxide production and transport in the soil, with the crop growth
model SUCROS. The original procedure of calculating plant root respiration in
SOILCO2-RothC is based on a depth-specific optimal CO2 production, which is modified
according to depth-specific soil temperature, water content and CO2 concentration in the
soil air over time. This rather simple approach for plant root CO2 production was
replaced by the plant physiological approach implemented in SUCROS, based on
relating maintenance and growth respiration to the CO2 assimilation rate of the
crop. We inverted the model for heterotrophic and autotrophic soil respiration using
chamber-based flux measurements in a winter wheat stand near Jülich (Germany) for the
growing periods of 2008 and 2009. The chamber-based separation of heterotrophic and
autotrophic respiration was done by root exclusion. 7-cm and 50-cm soil collars were
used to measure the sum of heterotrophic and autotrophic respiration and single
heterotrophic respiration, respectively. Autotrophic respiration was then calculated as the
difference between the CO2 fluxes of the two collar types. Furthermore, the growth and
biomass of the plants, soil temperature, soil water content and meteorological data
were measured. From this, we improved the model in terms of a more realistic
calculation of the plant root and microbial contributions to the overall soil respiration. |
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