HAL Id: hal-02827398
https://hal.inrae.fr/hal-02827398
Submitted on 7 Jun 2020
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Forest water stress modelling: comparison with long-term micrometeorological observations
Vincent Rivalland, Jean-Christophe Calvet, Yves Brunet, André Granier, Jean-Marc Guehl, Catherine Picon-Cochard
To cite this version:
Vincent Rivalland, Jean-Christophe Calvet, Yves Brunet, André Granier, Jean-Marc Guehl, et al..
Forest water stress modelling: comparison with long-term micrometeorological observations. European Geophysical Society, 27. General Assembly, Apr 2002, Nice, France. 1 p. �hal-02827398�
FOREST WATER STRESS MODELLING:
COMPARISON WITH LONG-TERM
MICROMETEOROLOGICAL OBSERVATIONS
V. Rivalland (1), J.-C. Calvet (1), Y. Brunet (2), A. Granier (3), J.-M. Guehl (4) and C. Picon-Cochard (5)
(1) Météo-France/CNRM, Toulouse (2) INRA/Bioclimatologie, Villenave d’Ornon, (3) INRA/EFN, Champenoux, (4) INRA/Bioclimatologie-Ecophysiologie, Champenoux, (5) INRA/Agronomie, Clermont-Ferrand, (vincent.rivalland@cnrm.meteo.fr/Fax:
+33-561079626)
The effect of drought on the parameters of a model of plant stomatal conductance is investigated in the case of woody plants, based on a large number of published leaf-level data. Thirty two experimental data sets are analysed in order to under- stand the inter-specific variations of the conductance and photosynthesis parameters in unstressed conditions. Four data sets of the same study include a soil drying cy- cle under present and doubled atmospheric CO2 concentration (350 and 700 ppm, respectively) for two tree species displaying markedly different responses to soil wa- ter stress. The behaviour of two model’s parameters is explored in both unstressed and stressed conditions: the mesophyll conductance and the maximum ratio between the intercellular and the atmospheric CO2 concentration (gm and fo, respectively, in stressed conditions, and gm* and fo* in unstressed conditions). An interspecific lin- ear relationship between ln(gm*) and fo* is found. A simple parameterisation of the evolution of ln(gm) and fo caused by drought is proposed for two distinct strategies, defensive and offensive. This woody stress parameterisation was implemented into the interaction between soil, vegetation and atmosphere, interactive vegetation model ISBA-A-gs and then tested on two forest canopies for which long-term micrometeo- rological measurements where available. The two forest consist of Pinus pinaster and Fagus sylvatica species, respectively, and are both sites of the European network Eu- roflux. Moreover, on the Pinus pinaster site, we tested a methodology to identify the understorey (Molinia coerulea) response to stress based on micrometeorological and physiological measurements.
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