La respiration hétérotrophe dans les sols agricoles : description des facteurs importants et comparaison de modèles semi-mécanistes existants

Abstract

Soil heterotrophic respiration in croplands: description of important driving factors and comparison of existing semi-mechanistic models. Soil heterotrophic respiration is a complex process which is governed by many biotic and abiotic factors. More specifically, in the agricultural ecosystems the influence of cultural practices and residue management techniques is important. Global change impacts on the phenomenon are still unclear. Some studies suggest that a positive feedback may occur. Therefore, it is necessary to get to a better knowledge of the mechanisms involved. To reach this goal, many semi-mechanistic models have been developed. Compared to empiric models, they allow a better understanding of soil carbon dynamics by distributing total soil carbon content into several pools. This carbon allocation is based on carbon decomposition constants. However, these models work at very different spatial and temporal scales and many differences exist between them. These ones are put forward in this paper and the main biotic and abiotic soil heterotrophic respiration factors are also described.

Keywords

• Soil heterotrophic respiration
• croplands
• process description
• semi-mechanistic models