API for the constants module
The models.animals.constants module contains a set of dataclasses containing
constants” (fitting relationships taken from the literature) required by the broader
animals module
The near-future intention is to rework the relationship between these constants and the AnimalCohort objects in which they are used such that there is a FunctionalType class in-between them. This class will hold the specific scaling, rate, and conversion parameters required for determining the function of a specific AnimalCohort and will avoid frequent searches through this constants file for values.
Classes:
|
Dataclass to store all constants related to metabolic rates. |
Data:
Fraction of carcass biomass that is assumed to decay rather than be consumed. |
|
Fraction of excrement that is assumed to decay rather than be consumed [unitless]. |
- class virtual_ecosystem.models.animals.constants.AnimalConsts(metabolic_rate_terms: dict[~virtual_ecosystem.models.animals.animal_traits.MetabolicType, dict[str, tuple[float, float]]] = <factory>, damuths_law_terms: dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, dict[~virtual_ecosystem.models.animals.animal_traits.DietType, tuple[float, float]]] = <factory>, fat_mass_terms: dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, tuple[float, float]] = <factory>, muscle_mass_terms: dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, tuple[float, float]] = <factory>, intake_rate_terms: dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, tuple[float, float]] = <factory>, energy_density: dict[str, float] = <factory>, conversion_efficiency: dict[~virtual_ecosystem.models.animals.animal_traits.DietType, float] = <factory>, mechanical_efficiency: dict[~virtual_ecosystem.models.animals.animal_traits.DietType, float] = <factory>, prey_mass_scaling_terms: dict[~virtual_ecosystem.models.animals.animal_traits.MetabolicType, dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, tuple[float, float]]] = <factory>, longevity_scaling_terms: dict[~virtual_ecosystem.models.animals.animal_traits.TaxaType, tuple[float, float]] = <factory>, birth_mass_threshold: float = 1.5, flow_to_reproductive_mass_threshold: float = 1.0, dispersal_mass_threshold: float = 0.8, energy_percentile_threshold: float = 0.5, decay_fraction_excrement: float = 0.5, decay_fraction_carcasses: float = 0.2)
Dataclass to store all constants related to metabolic rates.
TODO: The entire constants fille will be reworked in this style after the energy to mass conversion.
Attributes:
The reference mass for calculating diffusive juvenile dispersal in grams.
Time that it would take a herbivore of body mass equal to the reference mass, to handle one gram of autotroph biomass.
Reference mass for herbivore handling time.
The reference value for predator mass.
The standard deviations of the realized attack rates around the optimal predator-prey body mass ratio for which to calculate predator specific cumulative prey densities.
Diffusive dispersal speed on an individual of body-mass equal to M_disp_ref in km/month.
Effective rate per unit mass at which a herbivore searches its environment.
Effective rate per unit mass at which a predator searches its environment.
Herbivore exponent of the power-law function relating the handling time of autotroph matter to herbivore mass.
Carnivore exponent of the power-law relationship between the handling time of prey and the ratio of prey to predator body mass.
Ratio of current body-mass to adult body-mass at which starvation-response dispersal is attempted.
Intercept of the relationship between monthly temperature variability and the upper critical temperature limit relative to annual mean temperature, for terrestrial ectothermic functional groups.
Intercept of the relationship between monthly temperature variability and the optimal temperature relative to annual mean temperature, for terrestrial ectothermic functional groups.
Time that it would take a herbivore of body mass equal to the reference mass, to handle one gram of autotroph biomass
Time that it would take a predator of body mass equal to the reference mass, to handle a prey individual of body mass equal to one gram.
Slope of the relationship between monthly temperature variability and the upper critical temperature limit relative to annual mean temperature, for terrestrial ectothermic functional groups.
Slope of the relationship between monthly temperature variability and the optimal temperature relative to annual mean temperature, for terrestrial ectothermic functional groups.
Power law exponent for the scaling relationship between body-mass and dispersal distance as mediated by a reference mass, M_disp_ref.
Fraction of the resource stock that is available to any one herbivore cohort.
Proportion of the time step in which it's suitable to be active for functional group f.
The standard deviation of optimal predator-prey mass ratios among cohorts.
Standard deviation of the normal distribution describing realized attack rates around the optimal predator-prey body mass ratio.
Proportion of time for which functional group is active.
The mean optimal prey-predator body mass ratio, from which actual cohort optima are drawn.
The minimum optimal prey-predator body mass ratio.
- M_disp_ref = 1.0
The reference mass for calculating diffusive juvenile dispersal in grams.
- M_herb_0 = 0.7
Time that it would take a herbivore of body mass equal to the reference mass, to handle one gram of autotroph biomass.
- M_herb_ref = 1.0
Reference mass for herbivore handling time.
- M_pred_ref = 1.0
The reference value for predator mass.
- N_sigma_opt_pred_prey = 3.0
The standard deviations of the realized attack rates around the optimal predator-prey body mass ratio for which to calculate predator specific cumulative prey densities.
- V_disp = 0.0278
Diffusive dispersal speed on an individual of body-mass equal to M_disp_ref in km/month.
- alpha_0_herb = 1e-11
Effective rate per unit mass at which a herbivore searches its environment.
- alpha_0_pred = 1e-06
Effective rate per unit mass at which a predator searches its environment.
- b_herb = 0.7
Herbivore exponent of the power-law function relating the handling time of autotroph matter to herbivore mass.
- b_pred = 0.05
Carnivore exponent of the power-law relationship between the handling time of prey and the ratio of prey to predator body mass.
- beta_responsive_bodymass = 0.8
Ratio of current body-mass to adult body-mass at which starvation-response dispersal is attempted.
- c_tol = 6.61
Intercept of the relationship between monthly temperature variability and the upper critical temperature limit relative to annual mean temperature, for terrestrial ectothermic functional groups.
- c_tsm = 1.51
Intercept of the relationship between monthly temperature variability and the optimal temperature relative to annual mean temperature, for terrestrial ectothermic functional groups.
- h_herb_0 = 0.7
Time that it would take a herbivore of body mass equal to the reference mass, to handle one gram of autotroph biomass
- h_pred_0 = 0.5
Time that it would take a predator of body mass equal to the reference mass, to handle a prey individual of body mass equal to one gram.
- m_tol = 1.6
Slope of the relationship between monthly temperature variability and the upper critical temperature limit relative to annual mean temperature, for terrestrial ectothermic functional groups.
- m_tsm = 1.53
Slope of the relationship between monthly temperature variability and the optimal temperature relative to annual mean temperature, for terrestrial ectothermic functional groups.
- o_disp = 0.48
Power law exponent for the scaling relationship between body-mass and dispersal distance as mediated by a reference mass, M_disp_ref.
- phi_herb_t = 0.1
Fraction of the resource stock that is available to any one herbivore cohort.
- sigma_f_t = 0.5
Proportion of the time step in which it’s suitable to be active for functional group f.
- sigma_opt_f = 0.02
The standard deviation of optimal predator-prey mass ratios among cohorts.
- sigma_opt_pred_prey = 0.7
Standard deviation of the normal distribution describing realized attack rates around the optimal predator-prey body mass ratio.
- tau_f = 0.5
Proportion of time for which functional group is active.
- theta_opt_f = 0.1
The mean optimal prey-predator body mass ratio, from which actual cohort optima are drawn.
- theta_opt_min_f = 0.01
The minimum optimal prey-predator body mass ratio.
- virtual_ecosystem.models.animals.constants.DECAY_FRACTION_CARCASSES: float = 0.2
Fraction of carcass biomass that is assumed to decay rather than be consumed.
[unitless]. TODO - The number given here is very much made up, see
DECAY_FRACTION_EXCREMENTfor details of how this should be changed in future.
- virtual_ecosystem.models.animals.constants.DECAY_FRACTION_EXCREMENT: float = 0.5
Fraction of excrement that is assumed to decay rather than be consumed [unitless].
TODO - The number given here is very much made up. In future, we either need to find a way of estimating this from data, or come up with a smarter way of handling this process.