Functions to initialize and expand a ring of tracheids to simulate secondary growth.
Usage
woodformation_initRing()
woodformation_temperatureEffect(
Tc,
Y_T = 5,
DHa = 87500,
DSd = 1090,
DHd = 333000
)
woodformation_relativeExpansionRate(psi, Tc, pi, phi, Y_P, Y_T)
woodformation_growRing(
ring,
psi,
Tc,
Nc = 8.85,
phi0 = 0.13,
pi0 = -0.8,
CRD0 = 8.3,
Y_P = 0.05,
Y_T = 5,
h = 0.043 * 1.8,
s = 1.8
)
woodformation_relativeGrowthRate(dbh1, dbh2, yeardiff, lower = -2, upper = 8)
Arguments
- Tc
Temperature in Celsius.
- Y_T
Temperature yield threshold (in Celsius)
- 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).
- psi
Water potential (in MPa).
- pi
Osmotic potential (in MPa)
- phi
Cell extensibility (in MPa-1 day-1)
- Y_P
Turgor pressure yield threshold (in MPa)
- ring
An object of class
ring
returned by functionwoodformation_initRing
.- 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
- h
Cell wall hardening coefficient (in day-1)
- s
Cell wall softening coefficient (unitless)
- 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.
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.
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.
Parent, B., O. Turc, Y. Gibon, M. Stitt, and F. Tardieu. 2010. Modelling temperature-compensated physiological rates, based on the co-ordination of responses to temperature of developmental processes. Journal of Experimental Botany 61:2057–2069.