Variabilité de la respiration hétérotrophe du sol dans des écosystèmes agricoles: Analyse à différentes échelles spatiales et temporelles.

Soil heterotrophic respiration (HR) was studied at different spatial and temporal scales in agricultural ecosystems in Belgium (loamy region). Results from both laboratory and field experiments conducted at short and long timescales were analysed with the aim to better understand the influence of driving variables such as temperature, substrate input quantity and quality on HR. Both empirical and semi-mechanistic models were used in order to help interpret experimental results. Our observations showed that temperature is an important HR driving variable in agricultural ecosystems in temperate regions. HR sensitivity to temperature, characterized by a Q10 differing from 2 in our experiments, was very likely influenced by substrate availability and quality. The impact of these last two factors was however never observed through our measurements. Good agreement between modelled and observed CO2 fluxes in the incubation experiment, where carbon substrate was limited, suggested that temperature played a role both directly (enzymatic response) and indirectly (labile carbon stock depletion) at a relatively short term, and confirmed the hypothesis of occurrence of abiotic fluxes linked to the presence of carbonates in the samples taken from a limed agricultural field. Crop residue management (in both quantity and quality), as characterized by relatively low input levels in our experiment, influenced soil carbon stocks in the long term. However, HR, microbial biomass, labile carbon and metabolic diversity were not affected by the investigated treatments. Besides, results from both soil carbon budgets and short term HR measurements showed that supposedly large differences were likely to be reduced due to the relatively large proportion of root residues, weeds and residues unexported at harvest.

Grantor dc:publisher

ULiège - Université de Liège

Year dc:date

2013

Author dc:creator

• Buysse, Pauline

Contributors dc:contributor

• Aubinet, Marc
• Unit of Biosystem Physics

• Soil heterotrophic respiration
• Agricultural ecosystems
• Residue management
• Temperature
• Variability
• Respiration hétérotrophe du sol
• Ecosystèmes agricoles
• Gestion des résidus de culture
• Température
• Variabilité
• Life sciences
• Environmental sciences & ecology
• Agriculture & agronomy
• Sciences du vivant
• Sciences de l’environnement & écologie
• Agriculture & agronomie

Statement dc:rights

• restricted access
• info:eu-repo/semantics/restrictedAccess

Licence

• http://purl.org/coar/access_right/c_16ec

Language dc:language

fr

Identifier

info:hdl:2268/148816

OAI identifier oai:identifier

oai:orbi.ulg.ac.be:2268/148816