Biomass
The biomass module contains all functions related to biomass production data components.
- fpar(ndvi, fpar_slope=1.257, fpar_offset=-0.161)
Computes the fraction of absorbed PAR. PAR is photosynthetically active radiation, which is the solar radiation in the spectral range from 400-700 nm that is used by plants in photosynthesis. This function computes the fpar as a linear function of the ndvi, and is bounded between 0 and 1.
\[f_{par}=\Delta_{p} \cdot I_{ndvi} + c_{p}\]- Parameters
ndvi (float) – normalized difference vegetation index \(I_{ndvi}\) [-]
fpar_slope (float) – slope of the fpar-ndvi curve \(\Delta_{p}\) [-]
fpar_offset (float) – offset of the fpar-ndvi curve \(c_{p}\) [-]
- Returns
f_par – fraction of absorbed photosynthetically active radiation \(f_{par}\) [-]
- Return type
float
Examples
>>> import qattara.components.biomass as bio >>> bio.fpar(0.4) 0.34179999999999999
- par(ra_24)
Computes the photosynthetically active radiation (PAR). PAR is the solar radiation in the spectral range from 400-700 nm that is used by plants for photosynthesis.
\[PAR=r_{PAR} \cdot S^{\downarrow}\]where the following constant is used
\(r_{PAR}\) = ratio par/solar radiation [-] = 0.48
- Parameters
ra_24 (float) – incoming shortwave radiation \(S^{\downarrow}\) [W/m2]
- Returns
apar – photosynthetically active radiation \(PAR\) [W/m2]
- Return type
float
Examples
>>> import qattara.components.biomass as bio >>> bio.par(400.0) 192.0
- co2_level_annual(year)
Computes the annual CO2 level based on the linear relation of Roel Van Hoolst (Copernicus).
- Parameters
year (integer) – year of interest \(y\) [-]
- Returns
co2_act – actual annual CO2 level \(CO_2act\) [ppmv]
- Return type
float
Examples
#>>> from qattara import biomass #>>> import numpy as np #>>> biomass.t_air_kelvin(np.array([12.5,18.3])) #array([ 285.65, 291.45])
- temperature_dependency(t_air_k_12, dh_ap=52750, d_s=704.98, dh_dp=211000)
Computes the temperature dependency factor of GPP.
- Parameters
t_air_k_12 (float) – daytime air temperature \(T_{a,12}\) [K]
dh_ap (float) – activation energy \(\delta DH_{a,P}\) [J/mol]
d_s (float) – entropy of the denaturation equilibrium of CO2 \(\delta S\) [J/K.mol]
dh_dp (float) – deactivation energy \(\delta H_{d,P}\) [J/mol]
- Returns
t_dep – temperature dependency factor \(p(T_{atm})\) [-]
- Return type
float
- co2_o2_specificity_ratio(t_air_k_12)
Computes the CO2/O2 specificity ratio
- Parameters
t_air_k_12 (float) – daytime air temperature \(T_{a,12}\) [K]
- Returns
tau_co2_o2 – CO2/O2 specificity ratio \(\tau_CO{2}O{2}\) [-]
- Return type
float
- inhibition_constant_o2(t_air_k_12)
Computes the inhibition constant for O2
- Parameters
t_air_k_12 (float) – daytime air temperature \(T_{a,12}\) [K]
- Returns
k_0 – inhibition constant for O2 \(K_0\) [% O2]
- Return type
float
- affinity_constant_co2(t_air_k_12)
Computes the affinity constant for CO2 of Rubisco
- Parameters
t_air_k_12 (float) – daytime air temperature \(T_{a,12}\) [K]
- Returns
k_m – affinity constant for CO2 of Rubisco \(K_m\) [% CO2]
- Return type
float
- co2_fertilisation(tau_co2_o2, k_m, k_0, co2_act, o2=20.9, co2_ref=281)
Computes the normalized CO2 fertilization factor (Veroustraete, 1994). No fertilization means values equal to 1. Fertilization means values larger than 1.
- Parameters
tau_co2_o2 (float) – CO2/O2 specificity ratio \(\tau_CO{2}O{2}\) [-]
k_m (float) – affinity constant for CO2 of Rubisco \(K_m\) [% CO2]
k_0 (float) – inhibition constant for O2 \(K_0\) [% O2]
co2_act (float) – actual annual CO2 level \(CO_2act\) [ppmv]
o2 (float) – O2 concentration \(O_2\) [%]
co2_ref (float) – reference CO2 level \(CO_2ref\) [ppmv]
- Returns
co2_fert – CO2 fertilization effect \(CO_2fert\) [-]
- Return type
float
- autotrophic_respiration(t_air_k_24, ar_slo=0.0, ar_int=0.5)
Computes the fraction lost to autotrophic respiration
- Parameters
t_air_k_24 (float) – daily air temperature \(T_{a,24}\) [K]
ar_slo (float) – slope to determine autotrophic respiratory fraction \(AR_{slo}\) [-]
ar_int (float) – intercept to determine autotrophic respiratory fraction \(AR_{int}\) [-]
- Returns
a_d – autotrophic respiratory fraction \(A_d\) [-]
- Return type
float
- net_primary_production_max(t_dep, co2_fert, a_d, apar, gcgdm=0.45)
Computes the maximum Net Primary Production.
- Parameters
t_dep (float) – temperature dependency factor \(p(T_{atm})\) [-]
co2_fert (float) – CO2 fertilization effect \(CO_2fert\) [-]
a_d (float) – autotrophic respiratory fraction \(A_d\) [-]
apar (float) – photosynthetic active radiation \(PAR\) [W/m2]
gcgdm (float) – conversion factor enabling the conversion from DM to C \(gCgDM\) [-]
- Returns
npp_max – maximum net primary production \(NPP_{max}\) [gC/m2]
- Return type
float
- net_primary_production(npp_max, f_par, stress_moist, phot_eff=2.49)
Computes the maximum Net primary Production.
- Parameters
npp_max (float) – maximum net primary production \(NPP_{max}\) [-]
phot_eff (float) – Default Radiation Use Efficiency :math:` eps` [gDM/MJ(APAR)]
f_par (float) – fraction of absorbed photosynthetically active radiation \(f_{par}\) [-]
stress_moist (float) – stress factor of root zone moisture \(S_{m}\) [-]
- Returns
npp – net primary production \(NPP\) [gC/m2]
- Return type
float