Modelling hydraulic functioning of an adult beech stand under non-limiting soil water and severe drought condition

Autor: Marianne Peiffer, Andrée Tuzet, André Granier, Alain Perrier, Pauline Betsch
Přispěvatelé: Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Ecological Modelling
Ecological Modelling, Elsevier, 2017, 348, pp.56-77. ⟨10.1016/j.ecolmodel.2017.01.007⟩
Ecological Modelling, 2017, 348, pp.56-77. ⟨10.1016/j.ecolmodel.2017.01.007⟩
ISSN: 0304-3800
DOI: 10.1016/j.ecolmodel.2017.01.007⟩
Popis: • SPAC model to predict forest water consumption under wet and dry conditions.• Interactions and feedbacks between physical climate and ecological processes.• Control of root water uptake by water diffusion processes between roots and soil.• Key processes involved: xylem hydraulic resistances and stomatal conductance.• Buffering action of capacitive discharge on daily fluctuations of xylem tension.Modelling hydraulic functioning of a forest stand is a prerequisite to predict the future impact of climate change on forests. In this paper, we used a process-based model of the soil-plant-atmosphere continuum to investigate the links between energy budget and water balance, and to emphasize the key processes involved in the control of transpiration and water status of forest trees. The model describes stomatal conductance as a function of photosynthesis, intercellular CO2 concentration and leaf water potential. The latter in turn depends on soil and tree storage water potentials, the water flux through the soil and the trees, hydraulic resistances and stomatal conductance. We have implemented in the model a detailed tree water storage scheme, canopy interception of precipitation, and the rate of change of forest canopy energy storage. In this model, physical climate processes and ecological processes are closely coupled which involves important interactions and feedbacks. The model reproduces the observed variation in leaf water potential in dry and wet conditions. It successfully captures the decrease in soil water content under both non-limiting soil water and severe drought conditions and there is a good agreement between measured and simulated sensible and latent heat fluxes throughout the season. Simulations also show that significant amounts of intercepted water can be lost through evaporation during rain events. The results corroborate that the concept of hydraulic capacitance provides a simple and effective means of simulating the buffering action of tree water storage on tree water status. The two key parameters that control transpiration and water status of the trees are xylem hydraulic resistances and sensitivity of stomata to leaf water potential. The results confirm that stomatal conductance cannot be modelled using leaf-level processes alone, but must be incorporated into a comprehensive model of water flow from soil through the plants to the atmosphere where various self-regulation are set up to ensure a complete water status equilibrium.
Databáze: OpenAIRE
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