C3 temperature response parameters from Sharkey et al.
c3_temperature_param_sharkey.Rd
Parameters describing the temperature response of important C3 photosynthetic
parameters, intended to be passed to the
calculate_temperature_response
function.
Format
List with 11 named elements that each represent a variable whose temperature-dependent value can be calculated using an Arrhenius equation or a polynomial equation:
Gamma_star_at_25
: The value of chloroplastic CO2 concentration at which CO2 gains from Rubisco carboxylation are exactly balanced by CO2 losses from Rubisco oxygenation (Gamma_star
) at 25 degrees C.Gamma_star_norm
:Gamma_star
normalized to its value at 25 degrees C.gmc_norm
: The mesophyll conductance to CO2 diffusion (gmc
) normalized to its value at 25 degrees C.J_norm
: The electron transport rate (J
) normalized to its value at 25 degrees C.Kc_at_25
: The Michaelis-Menten constant for rubisco carboxylation (Kc
) at 25 degrees C.Kc_norm
:Kc
normalized to its value at 25 degrees C.Ko_at_25
: The Michaelis-Menten constant for rubisco oxygenation (Ko
) at 25 degrees C.Ko_norm
:Ko
normalized to its value at 25 degrees C.RL_norm
: The rate of non-photorespiratory CO2 release in the light (RL
) normalized to its value at 25 degrees C.Tp_norm
: The maximum rate of triose phosphate utilization (Tp
) normalized to its value at 25 degrees C.Vcmax_norm
: The maximum rate of rubisco carboxylation (Vcmax
) normalized to its value at 25 degrees C.
In turn, each of these elements is a list with at least 2 named elements:
type
: the type of temperature responseunits
: the units of the corresponding variable.
Source
Many of these parameters are normalized to their values at 25 degrees C. These
variables include _norm
in their names to indicate this.
Response parameters were obtained from Sharkey et al. (2007). In this
publication, gas concentrations are expressed as partial pressures (in
Pa
or kPa
) rather than mole fractions (micromol / mol
or
mmol / mol
). However, for consistency with
c3_temperature_param_bernacchi
, here we prefer to use mole
fractions.
To convert a concentration expressed as a partial pressure (P
; in
Pa
) to a concentration expressed as a mole fraction (C
; in
micromol / mol
), we need a value for atmospheric pressure; we will use
the typical value of 101325 Pa
. Then C = P / 101325 * 1e6
or
C = P * cf
, where cf = 1e6 / 101325
is a conversion factor. The
same correction can be used to convert kPa
to mmol / mol
. The
value of cf
can be accessed using PhotoGEA:::c_pa_to_ppm
.
References:
Sharkey, T. D., Bernacchi, C. J., Farquhar, G. D. & Singsaas, E. L. "Fitting photosynthetic carbon dioxide response curves for C3 leaves" Plant, Cell & Environment 30, 1035–1040 (2007) [doi:10.1111/j.1365-3040.2007.01710.x ].