Wood formation: Wood formation

Description

Functions to initialize and expand a ring of tracheids to simulate secondary growth.

Usage

woodformation_initRing()
woodformation_growRing(ring, psi, Tc,
                       Nc=8.85, phi0=0.13, pi0=-0.8, CRD0=8.3,
                       Y_P=0.05, Y_T=5.0, h=0.043*1.8, s=1.8)
woodformation_relativeExpansionRate(psi, Tc, pi, phi, Y_P, Y_T)
woodformation_temperatureEffect(Tc, Y_T=5.0, DHa=87.5e3, DSd=1.09e3, DHd=333e3)
woodformation_relativeGrowthRate(dbh1, dbh2, yeardiff, lower = -2, upper = 8)

Value

Function woodformation_initRing() returns a list of class 'ring', that is a list containing a data frame cells and two vectors: P and SA. Dataframe cells contains the columns "formation_date", "phi", "pi" and "CRD" and as many rows as dates processed. Vectors P and SA contain, respectively, the number of cells produced and the sapwood area corresponding to the ring of cells (assuming a tangencial radius of 20 micrometers). Function woodformation_growRing() modifies the input 'ring' object according to the environmental conditions given as input. Function woodformation_relativeExpansionRate() returns a numeric scalar with the relative expansion rate. Function woodformation_temperatureEffect() returns a scalar between 0 and 1 reflecting the temperature effect on tissue formation rate. Function woodformation_relativeGrowthRate returns the annual growth rate, relative to cambium perimeter, estimated from initial and final diameter values.

Arguments

ring: An object of class ring returned by function woodformation_initRing.
psi: Water potential (in MPa).
Tc: Temperature in Celsius.
Nc: Number of active cells in the cambium.
phi0: Initial value of cell extensibility (in MPa-1 day-1)
pi0: Initial value of cell osmotic potential (in MPa)
CRD0: Initial value of cell radial diameter
Y_P: Turgor pressure yield threshold (in MPa)
Y_T: Temperature yield threshold (in Celsius)
h: Cell wall hardening coefficient (in day-1)
s: Cell wall softening coefficient (unitless)
pi: Osmotic potential (in MPa)
phi: Cell extensibility (in MPa-1 day-1)
DHa, DSd, DHd: Enthalpy of activation, enthalpy difference and entropy difference between the catalytically active and inactive states of the enzymatic system (Parent et al. 2010).
dbh1, dbh2: Initial and final diameter at breast height.
yeardiff: Interval between dbh measurements, in years.
lower, upper: Lower and upper bounds for root finding.

Author

Antoine Cabon, CTFC

Miquel De Cáceres Ainsa, CREAF

References

Cabon A, Fernández-de-Uña L, Gea-Izquierdo G, Meinzer FC, Woodruff DR, Martínez-Vilalta J, De Cáceres M. 2020a. Water potential control of turgor-driven tracheid enlargement in Scots pine at its xeric distribution edge. New Phytologist 225: 209–221.

Cabon A, Peters RL, Fonti P, Martínez-Vilalta J, De Cáceres M. 2020b. Temperature and water potential co-limit stem cambial activity along a steep elevational gradient. New Phytologist: nph.16456.