 |
| Titel |
Dual-chamber measurements of δ¹³C of soil-respired CO2 partitioned using a field-based three end-member model |
| VerfasserIn |
F. Albanito, J. McAllister, P. Smith, D. Robinson |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059552
|
|
|
|
|
|
| Zusammenfassung |
| Reliably estimating the heterotrophic component of RS is crucial for the characterisation of an ecosystem’s net C balance. However, the contribution of ‘historical’ soil C (SOM) to total soil respiration (RS) in forest remains still uncertain. One of the contributing factors of this uncertainty is the difficulty to reliably measure and partition key carbon-cycle processes. Isotopic methods, such as natural variations in carbon isotope composition (δ13C) of soil respiration, are more frequently being applied, and show promise in separating heterotrophic and autotrophic contributions to RS. In this study we report the partitioning of soil-surface CO2 effluxes, measured in forests in Italy and in Germany, using a new field-based δ13C method and a three end-member mixing model. Soil-surface CO2 flux was partitioned into components derived from root, litter/humus and SOM sources, and compared this with the conventional partitioning into autotrophic and heterotrophic components (two end-member mixing model). In addition, we used a novel dual-chamber technique to ensure that measurements of δ13CRs were subjected to minimal artefacts during measurement. Our results provide new information about the contributions of belowground components to the CO2 flux at the soil surface, and show an alternative approach to the partitioning of RS components using their 13C signatures. |
|
|
|
|
|
|