hydraulics: Hydraulic model functions

Description

Set of functions used in the implementation of Sperry and Love's (2015) hydraulic model.

Usage

hydraulics.E2psiXylem(E, psiUpstream, kxmax, c, d, psiStep = -0.01, 
                 psiMax = -10.0)
hydraulics.E2psiVanGenuchten(E, psiSoil, ksmax, n, alpha, 
                             psiStep = -0.01, psiMax = -10.0)
hydraulics.E2psiTwoElements(E, psiSoil, ksmax, kxmax, n, alpha, c, d, 
                            psiStep = -0.001, psiMax = -10.0)
hydraulics.Ecrit(psiUpstream, kxmax, c, d)
hydraulics.EXylem(psiPlant, psiUpstream, kxmax, c, d)
hydraulics.supplyFunction(Emax, psiSoil, ksmax, kxmax, n, alpha, c, d, 
                          dE = 0.1, psiMax = -10.0)
hydraulics.psiCrit(c, d)
hydraulics.regulatedPsiXylem(E, psiUpstream, kxmax, c, d, psiStep = -0.01)
hydraulics.regulatedPsiTwoElements(Emax, psiSoil, ksmax, kxmax, n, alpha, 
                                   c, d, dE = 0.1, psiMax = -10.0)
hydraulics.vanGenuchtenConductance(psi, ksmax, n, alpha)
hydraulics.xylemConductance(psi, kxmax, c, d)

Arguments

Flow per surface unit.

Emax

Maximum flow per surface unit.

psi

Water potential (in MPa).

psiUpstream

Water potential upstream (in MPa). In a one-component model corresponds to soil potential. In a two-component model corresponds to the potential inside the roots.

psiPlant

Plant water potential (in MPa).

psiSoil

Soil water potential (in MPa).

psiStep

Water potential precision (in MPa).

psiMax

Minimum (maximum in absolute value) water potential to be considered (in MPa).

Flow precision.

kxmax

Maximum xylem hydraulic conductance (defined as flow per surface unit and per pressure drop).

ksmax

Maximum rhizosphere hydraulic conductance (defined as flow per surface unit and per pressure drop).

c, d

Parameters of the Weibull function (plant vulnerability curve).

n, alpha

Parameters of the Van Genuchten function (rhizosphere vulnerability curve).

Value

Values returned for each function are:

hydraulics.E2psiXylem: The plant (leaf) water potential (in MPa) corresponding to the input flow, according to the xylem supply function and given an upstream (soil or root) water potential.
hydraulics.E2psiVanGenuchten: The root water potential (in MPa) corresponding to the input flow, according to the rhizosphere supply function and given a soil water potential.
hydraulics.E2psiTwoElements: The plant (leaf) water potential (in MPa) corresponding to the input flow, according to the rhizosphere and plant supply functions and given an input soil water potential.
hydraulics.Ecrit: The critical flow according to the xylem supply function and given an input soil water potential.
hydraulics.EXylem: The flow (integral of the vulnerability curve) according to the xylem supply function and given an input drop in water potential (rhizosphere and plant).
hydraulics.supplyFunction: A list with different numeric vectors with information of the two-element supply function:
- E: Flow values (supply values).
- FittedE: Fitted flow values.
- PsiRoot: Water potential inside the root values.
- PsiPlant: Plant water potential values.
- dEdP: Derivatives of the supply function.
hydraulics.psiCrit: Critical water potential (in MPa) according to the xylem vulnerability curve.
hydraulics.regulatedPsiXylem: Plant water potential after regulation (one-element loss function) given an input water potential.
hydraulics.regulatedPsiTwoElements: Plant water potential after regulation (two-element loss function) given an input soil water potential.
hydraulics.vanGenuchtenConductance: Rhizosphere conductance corresponding to an input water potential (soil vulnerability curve).
hydraulics.xylemConductance: Xylem conductance (flow rate per pressure drop) corresponding to an input water potential (plant vulnerability curve).

Details

Details of the hydraulic model are given in a vignette.

References