Simulated and measured water uptake by picea abies under non-limiting soil water conditions

• Published in: Agricultural and forest meteorology Vol. 71; no. 1; pp. 147 - 164
• Main Authors: Cienciala, Emil, Eckersten, Henrik, Lindroth, Anders, Hällgren, Jan-Erik
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.1994; Oxford Elsevier; New York, NY
• Subjects: ABSORCION DE AGUA; ABSORCION DE SUSTANCIAS NUTRITIVAS; ABSORPTION D'EAU; ABSORPTION DE SUBSTANCES NUTRITIVES; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; BALANCE HIDRICO DEL SUELO; BILAN HYDRIQUE DU SOL; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; MODELE DE SIMULATION; MODELOS DE SIMULACION; NUTRIENT UPTAKE; PICEA ABIES; SIMULATION MODELS; SOIL WATER BALANCE; SUECIA; SUEDE; SWEDEN; Water balance and requirements. Evapotranspiration; WATER UPTAKE; Sweden; Europe; Biometeorology; Water; Measurement; Parametrization; Soil plant atmosphere relation; Flow measurement; Forest soil; Modeling; Compartmental model; Model calibration; Model matching; Water regime; Softwood forest tree; Gymnospermae; Aerodynamic resistance; Water absorption; Pool; Simulation model; Mathematical model; Validation; Sensitivity analysis; Root; Soil moisture; Stomatal conductance; Biophysics; Ecophysiology; Hydraulic resistance; Artificial forest stand; Applied mathematics; Flow(fluid); Forestry; One dimensional model; Numerical simulation; Coniferales; Air ground interface; Spermatophyta; Soil plant relation; Picea abies; Available water
• ISSN: 0168-1923; 1873-2240
• DOI: 10.1016/0168-1923(94)90105-8

A one-dimensional non-steady-state soil-plant-atmosphere continuum (SPAC) model was applied to a stand of Picea abies trees in southern Sweden. The simulated root water uptake was compared with measured sap flow under non-limiting soil water conditions. Sap flow was measured during the growing season using the tree-trunk heat balance method. The model included four resistances against water (soil-root, plant, stomatal and aerodynamic), one pool of easily available plant water and one compartment of intercepted water on the needle surface. The bulk stomatal resistance was estimated as the product of the combined effect of two independent variables—vapour pressure deficit and solar radiation. Good agreement between simulated and ‘measured’ water uptake was obtained both on short- and long-term scales, and the model explained 92–93% of the variation of measured uptake for both hourly and daily values. The pool of easily available water was found to be small (0.5 mm), i.e. of the same order as for agricultural crops.