Seasonal dynamics of soil carbon dioxide efflux and simulated rhizosphere respiration in a beech forest.
Tree Physiol
; 21(2-3): 145-52, 2001 Feb.
Article
en En
| MEDLINE
| ID: mdl-11303645
Respiration of the rhizosphere in a beech (Fagus sylvatica L.) forest was calculated by subtracting microbial respiration associated with organic matter decomposition from daily mean soil CO2 efflux. We used a semi-mechanistic soil organic matter model to simulate microbial respiration, which was validated against "no roots" data from trenched subplots. Rhizosphere respiration exhibited pronounced seasonal variation from 0.2 g C m(-2) day(-1) in January to 2.3 g C m(-2) day(-1) in July. Rhizosphere respiration accounted for 30 to 60% of total soil CO2 efflux, with an annual mean of 52%. The high Q10 (3.9) for in situ rhizosphere respiration was ascribed to the confounding effects of temperature and changes in root biomass and root and shoot activities. When data were normalized to the same soil temperature based on a physiologically relevant Q10 value of 2.2, the lowest values of temperature-normalized rhizosphere respiration were observed from January to March, whereas the highest value was observed in early July when fine root growth is thought to be maximal.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Suelo
/
Árboles
/
Raíces de Plantas
/
Fagus
País/Región como asunto:
Europa
Idioma:
En
Revista:
Tree Physiol
Asunto de la revista:
BOTANICA
/
FISIOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Canadá