API documentation for the constants module
The constants module contains
constants and parameters for the
litter_model. These parameters are constants
in that they should not be changed during a particular simulation.
Classes:
|
Dataclass to store all constants for the litter model. |
- class virtual_ecosystem.models.litter.constants.LitterConsts(litter_decomp_reference_temp: float = 40.0, litter_decomp_offset_temp: float = 31.79, litter_decomp_temp_response: float = 3.36, litter_decay_water_potential_optimum: float = -10.0, litter_decay_water_potential_halt: float = -28800.0, moisture_response_curvature: float = 1.0, litter_decay_constant_metabolic_above: float = 0.08, litter_decay_constant_structural_above: float = 0.021714285714285714, litter_decay_constant_woody: float = 0.006666666666666667, litter_decay_constant_metabolic_below: float = 0.1, litter_decay_constant_structural_below: float = 0.02702702702702703, litter_input_to_metabolic_above: float = 0.000280628, litter_input_to_structural_above: float = 0.00071869, litter_input_to_woody: float = 0.002586, litter_input_to_metabolic_below: float = 0.00042, litter_input_to_structural_below: float = 0.00048, cue_metabolic: float = 0.45, cue_structural_above_ground: float = 0.55, cue_woody: float = 0.55, cue_structural_below_ground: float = 0.45, lignin_inhibition_factor: float = -5.0, lignin_proportion_above_structural_input: float = 0.25, lignin_proportion_wood_input: float = 0.3, lignin_proportion_below_structural_input: float = 0.2)
Dataclass to store all constants for the litter model.
Attributes:
Carbon use efficiency of metabolic litter decay [unitless].
Carbon use efficiency of aboveground structural litter decay [unitless].
Carbon use efficiency of belowground structural litter decay [unitless].
Carbon use efficiency of woody litter decay [unitless].
Exponential factor expressing the extent that lignin inhibits litter breakdown.
Lignin proportion of input to the above ground structural litter pool [unitless].
Lignin proportion of input to the below ground structural litter pool [unitless].
Lignin proportion of dead wood input [unitless].
Decay constant for the above ground metabolic litter pool [day^-1].
Decay constant for the below ground metabolic litter pool [day^-1].
Decay constant for the above ground structural litter pool [day^-1].
Decay constant for the below ground structural litter pool [day^-1].
Decay constant for the woody litter pool [day^-1].
The water potential at which below ground litter decay stops entirely [kPa].
The water potential at which below ground litter decay is maximised [kPa].
Offset temperature for litter decomposition [C].
Reference temperature for litter decomposition [C].
Parameter controlling the temperature response strength of litter decomposition.
Litter input rate to metabolic above ground litter pool [kg C m^-2 day^-1].
Litter input rate to metabolic below ground litter pool [kg C m^-2 day^-1].
Litter input rate to metabolic above ground litter pool [kg C m^-2 day^-1].
Litter input rate to structural below ground litter pool [kg C m^-2 day^-1].
Litter input rate to woody litter pool [kg C m^-2 day^-1].
Curvature of the litter decay moisture response function [unitless].
- cue_metabolic: float = 0.45
Carbon use efficiency of metabolic litter decay [unitless].
The value given here is taken from Fatichi et al. (2019), but I can’t track down an empirical source. This carbon use efficiency is constant with temperature, soil moisture and substrate stoichiometry. These assumptions are not made in the soil model, but are used for the sake of simplicity here. If an improved version of the litter model gets made, this is a key area to address.
- cue_structural_above_ground: float = 0.55
Carbon use efficiency of aboveground structural litter decay [unitless].
The value given here is taken from Fatichi et al. (2019); see documentation for
cue_metabolicfor details.
- cue_structural_below_ground: float = 0.45
Carbon use efficiency of belowground structural litter decay [unitless].
The value given here is taken from Fatichi et al. (2019); see documentation for
cue_metabolicfor details.
- cue_woody: float = 0.55
Carbon use efficiency of woody litter decay [unitless].
The value given here is taken from Fatichi et al. (2019); see documentation for
cue_metabolicfor details.
- lignin_inhibition_factor: float = -5.0
Exponential factor expressing the extent that lignin inhibits litter breakdown.
[unitless]. The more negative this value the greater the strength of the inhibition. This value is taken from Kirschbaum and Paul (2002).
- lignin_proportion_above_structural_input: float = 0.25
Lignin proportion of input to the above ground structural litter pool [unitless].
TODO - The number given here is made up (but within reasonable bounds). However, this is a quantity that should be generated by the plant model.
- lignin_proportion_below_structural_input: float = 0.2
Lignin proportion of input to the below ground structural litter pool [unitless].
TODO - The number given here is made up (but within reasonable bounds). However, this is a quantity that should be generated by the plant model.
- lignin_proportion_wood_input: float = 0.3
Lignin proportion of dead wood input [unitless].
TODO - The number given here is made up (but within reasonable bounds). However, this is a quantity that should be generated by the plant model.
- litter_decay_constant_metabolic_above: float = 0.08
Decay constant for the above ground metabolic litter pool [day^-1].
Value is taken from Kirschbaum and Paul (2002).
- litter_decay_constant_metabolic_below: float = 0.1
Decay constant for the below ground metabolic litter pool [day^-1].
Value is taken from Kirschbaum and Paul (2002).
- litter_decay_constant_structural_above: float = 0.021714285714285714
Decay constant for the above ground structural litter pool [day^-1].
Value is taken from Kirschbaum and Paul (2002).
- litter_decay_constant_structural_below: float = 0.02702702702702703
Decay constant for the below ground structural litter pool [day^-1].
Value is taken from Kirschbaum and Paul (2002).
- litter_decay_constant_woody: float = 0.006666666666666667
Decay constant for the woody litter pool [day^-1].
Value is taken from Kirschbaum and Paul (2002) as the average of fine wood and coarse wood decay.
- litter_decay_water_potential_halt: float = -28800.0
The water potential at which below ground litter decay stops entirely [kPa].
Value is taken from :cite:t`moyano_responses_2013`.
- litter_decay_water_potential_optimum: float = -10.0
The water potential at which below ground litter decay is maximised [kPa].
Value is taken from :cite:t`moyano_responses_2013`.
- litter_decomp_offset_temp: float = 31.79
Offset temperature for litter decomposition [C].
Value is taken from Kirschbaum and Paul (2002).
- litter_decomp_reference_temp: float = 40.0
Reference temperature for litter decomposition [C].
Value is taken from Kirschbaum and Paul (2002).
- litter_decomp_temp_response: float = 3.36
Parameter controlling the temperature response strength of litter decomposition.
[unitless]. Value is taken from Kirschbaum and Paul (2002).
- litter_input_to_metabolic_above: float = 0.000280628
Litter input rate to metabolic above ground litter pool [kg C m^-2 day^-1].
This value was estimated (very unsystematically) from SAFE project data. This constant will eventually be removed once the litter is linked to other models.
- litter_input_to_metabolic_below: float = 0.00042
Litter input rate to metabolic below ground litter pool [kg C m^-2 day^-1].
This value was estimated (very unsystematically) from SAFE project data. This constant will eventually be removed once the litter is linked to other models.
- litter_input_to_structural_above: float = 0.00071869
Litter input rate to metabolic above ground litter pool [kg C m^-2 day^-1].
This value was estimated (very unsystematically) from SAFE project data. This constant will eventually be removed once the litter is linked to other models.
- litter_input_to_structural_below: float = 0.00048
Litter input rate to structural below ground litter pool [kg C m^-2 day^-1].
This value was estimated (very unsystematically) from SAFE project data. This constant will eventually be removed once the litter is linked to other models.
- litter_input_to_woody: float = 0.002586
Litter input rate to woody litter pool [kg C m^-2 day^-1].
This was calculated assuming that dead wood pools in old growth forest are at steady state. So, that the input will equal the dead wood respiration divided by 1 minus the carbon use efficiency. The value for dead wood respiration for old growth forest was taken from Mills et al. (2023). This constant will eventually be removed once the litter is linked to other models.