Summary• We studied the seasonal fluctuation of soil respiration (R S ), and its rootdependent (R R ) and basal (R B ) components, in a Vitis vinifera (Chardonnay) vineyard.• The R S components were estimated through independent field methods (y-intercept and trenching) and modeled on the basis of a Q 10 response to soil temperature, and fine and coarse root respiration coefficients. The effect of assimilate availability on R R was assessed through a trunk girdling treatment.• The apparent Q 10 for R R was twice that of R B (3.5 vs 1.6) and increased linearly with increasing vine root biomass. The fastest R R of fine roots was during rapid fruit growth and the fastest R R of coarse roots was immediately following fruit development. R S was estimated at 32.6 kg ha )1 d )1 (69% as a result of R R ) for the hottest month and at 7.6 kg ha )1 d )1 (18% as a result of R R ) during winter dormancy. Annual R S was low compared with other natural and cultivated ecosystems: 5.4 Mg ha )1 (46% as a result of R R ).• Our estimates of annual vineyard R S are the first for any horticultural crop and suggest that the assumption that they are similar to those of annual crops or forest trees might lead to an overestimation.

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