6.23. pft_params.nml

This file sets the time and space-invariant parameters for plant functional types for the JULES land surface model. It contains one namelist called JULES_PFTPARM.

Note

If the crop model is on (i.e. ncpft > 0), the order of PFTs must be natural PFTs followed by crop PFTs.

6.23.1. JULES_PFTPARM namelist members

This namelist reads the values of parameters for each of the plant functional types (PFTs) if the JULES land surface model is being used. These parameters are a function of PFT only. Parameters that also vary with time and location can be prescribed in prescribed_data.nml. Parameters that are only required if the dynamic vegetation (TRIFFID) or phenology sections are requested are read separately in triffid_params.nml. Every member must be given a value for every run.

HCTN24 and 30 refer to Hadley Centre technical notes 24 and 30, available from the Met Office Library. For ease the direct links to these documents are:

• HCTN24 “Description of the “TRIFFID” Dynamic Global Vegetation Model”

• HCTN30 “MOSES 2.2 technical documentation”

JULES_PFTPARM::canht_ft_io

Type:

real(npft)

Default:

None

The height of each PFT (m), also known as the canopy height.

The value read here is only used if TRIFFID is not active (l_triffid = FALSE).

Note

If TRIFFID is active, canopy height is a prognostic variable and its initial value is read in initial_conditions.nml.

JULES_PFTPARM::lai_io

Type:

real(npft)

Default:

None

The leaf area index (LAI) of each PFT.

The value read here is only used if neither phenology nor TRIFFID is active (l_phenol = FALSE and l_triffid = FALSE).

Note

If phenology is active, LAI is a prognostic variable and its initial value is read in initial_conditions.nml. When TRIFFID is active but phenology is not active (not recommended), LAI is calculated from the canopy height (meaning that the seasonal cycle of LAI will not be correctly represented).

JULES_PFTPARM::c3_io

Type:

integer(npft)

Default:

None

Flag indicating whether PFT is C3 type.

0. Not C3 (i.e. C4).

1. C3.

JULES_PFTPARM::orient_io

Type:

integer(npft)

Default:

None

Flag indicating leaf angle distribution.

0. Spherical.

1. Horizontal.

JULES_PFTPARM::can_struct_a_io

Type:

real(npft)

Default:

None

Canopy structure factor (dimensionless). can_struct_a_io=1.0 indicates a structurally homogeneous canopy. Corresponds to the structure factor Zeta in Pinty et al 2006 except assumed not to vary with zenith angle i.e. b=0. The canopy structure factor has no effect if can_rad_mod = 1.

JULES_PFTPARM::a_wl_io

Type:

real(npft)

Default:

None

Allometric coefficient relating the target woody biomass to the leaf area index (kg carbon m^-2) (Clark et al., 2011; Table 7)

JULES_PFTPARM::a_ws_io

Type:

real(npft)

Default:

None

Woody biomass as a multiple of live stem biomass (Clark et al., 2011; Table 7).

JULES_PFTPARM::albsnc_max_io

Type:

real(npft)

Default:

None

Snow-covered albedo for large leaf area index.

Only used if l_snow_albedo = FALSE. See HCTN30 Eq.2.

JULES_PFTPARM::albsnc_min_io

Type:

real(npft)

Default:

None

Snow-covered albedo for zero leaf area index.

Only used if l_snow_albedo = FALSE. See HCTN30 Eq.2.

JULES_PFTPARM::albsnf_max_io

Type:

real(npft)

Default:

None

Snow-free albedo for large LAI.

Only used if l_spec_albedo = FALSE. See HCTN30 Eq.1.

JULES_PFTPARM::albsnf_maxu_io

Type:

real(npft)

Default:

None

Upper bound for the snow-free albedo for large LAI, when scaled to match input obs.

Only used if l_spec_albedo = FALSE and l_albedo_obs = TRUE.

JULES_PFTPARM::albsnf_maxl_io

Type:

real(npft)

Default:

None

Lower bound for the snow-free albedo for large LAI, when scaled to match input obs.

Only used if l_spec_albedo = FALSE and l_albedo_obs = TRUE.

JULES_PFTPARM::alpha_io

Type:

real(npft)

Default:

None

Quantum efficiency of photosynthesis (mol CO₂ per mol PAR photons).

JULES_PFTPARM::alnir_io

Type:

real(npft)

Default:

None

Leaf reflection coefficient for NIR. See HCTN30 Table 3.

Always used unless can_rad_mod = 1 and l_spec_albedo = FALSE.

JULES_PFTPARM::alniru_io

Type:

real(npft)

Default:

None

Upper limit for the leaf reflection coefficient for NIR, when l_albedo_obs = TRUE and when alnir_io is used.

JULES_PFTPARM::alnirl_io

Type:

real(npft)

Default:

None

Lower limit for the leaf reflection coefficient for NIR, when l_albedo_obs = TRUE and when alnir_io is used.

JULES_PFTPARM::alpar_io

Type:

real(npft)

Default:

None

Leaf reflection coefficient for VIS (photosyntehtically active radiation). See HCTN30 Table 3.

Always used unless can_rad_mod = 1 and l_spec_albedo = FALSE.

JULES_PFTPARM::alparu_io

Type:

real(npft)

Default:

None

Upper limit for the leaf reflection coefficient for VIS, when l_albedo_obs = TRUE and when alpar_io is used.

JULES_PFTPARM::alparl_io

Type:

real(npft)

Default:

None

Lower limit for the leaf reflection coefficient for VIS, when l_albedo_obs = TRUE and when alpar_io is used.

JULES_PFTPARM::b_wl_io

Type:

real(npft)

Default:

None

Allometric exponent relating the target woody biomass to the leaf area index. This is 5/3 in HCTN24 Eq.8. See also Clark et al. (2011, Table 7).

JULES_PFTPARM::catch0_io

Type:

real(npft)

Default:

None

Minimum canopy capacity (kg m^-2).

This is the minimum amount of water that can be held on the canopy. See HCTN30 p7.

JULES_PFTPARM::dcatch_dlai_io

Type:

real(npft)

Default:

None

Rate of change of canopy capacity with LAI (kg m^-2).

Canopy capacity is calculated as catch0 + dcatch_dlai*lai. See HCTN30 p7.

JULES_PFTPARM::dgl_dm_io

Type:

real(npft)

Default:

None

Rate of change of leaf turnover rate with moisture availability.

JULES_PFTPARM::dgl_dt_io

Type:

real(npft)

Default:

None

Rate of change of leaf turnover rate with temperature (K^-1).

This is 9 in HCTN24 Eq.10.

JULES_PFTPARM::dqcrit_io

Type:

real(npft)

Default:

None

Critical humidity deficit (kg H₂O per kg air).

Only used with the Jacobs model of stomatal conductance (stomata_model = 1).

JULES_PFTPARM::dz0v_dh_io

Type:

real(npft)

Default:

None

Rate of change of vegetation roughness length for momentum with height.

Roughness length is calculated as dz0v_dh * canht_ft. See HCTN30 p5.

Used if logical l_spec_veg_z0 is set to .false.

JULES_PFTPARM::z0v_io

Type:

real(npft)

Default:

None

Specified values for the vegetation roughness length for momentum.

Used if logical l_spec_veg_z0 is set to .true.

JULES_PFTPARM::eta_sl_io

Type:

real(npft)

Default:

None

Live stemwood coefficient (kg C/m/(m2 leaf)) (Clark et al., 2011; Table 7).

JULES_PFTPARM::fd_io

Type:

real(npft)

Default:

None

Scale factor for dark respiration. See HCTN 24 Eq. 56.

JULES_PFTPARM::fsmc_of_io

Type:

real(npft)

Default:

None

Moisture availability below which leaves are dropped.

JULES_PFTPARM::f0_io

Type:

real(npft)

Default:

None

CI / CA for DQ = 0. See HCTN 24 Eq. 32.

Only used with the Jacobs model of stomatal conductance (stomata_model = 1).

JULES_PFTPARM::g1_stomata_io

Type:

real(npft)

Default:

None

Parameter g1 for the Medlyn et al. (2011) model of stomatal conductance (kPa^0.5) - this is the sensitivity of the stomatal conductance to the assimilation rate. See Eqn.11 in Medlyn et al. (2012), https://doi.org/10.1111/j.1365-2486.2012.02790.x.

Only used with the Medlyn model of stomatal conductance (stomata_model = 2).

JULES_PFTPARM::g_leaf_0_io

Type:

real(npft)

Default:

None

Minimum turnover rate for leaves (/360days).

JULES_PFTPARM::glmin_io

Type:

real(npft)

Default:

None

Minimum leaf conductance for H₂O (m s^-1).

JULES_PFTPARM::infil_f_io

Type:

real(npft)

Default:

None

Infiltration enhancement factor.

The maximum infiltration rate defined by the soil parameters for the whole gridbox may be modified for each PFT to account for PFT-dependent factors, such as macro-pores related to vegetation roots.

See HCTN30 p14 for full details.

JULES_PFTPARM::gsoil_f_io

Type:

real(npft)

Default:

None

Soil conductance enhancement factor.

The soil conductance for soil under a PFT canopy may be modified for each PFT (as compared to the bare soil conductance) to account for PFT-dependent factors.

JULES_PFTPARM::hw_sw_io

Type:

real(npft)

Default:

None

Ratio of N stem to N heartwood (kgN/kgN) from the TRY database.

Only used if l_trait_phys = T.

JULES_PFTPARM::kext_io

Type:

real(npft)

Default:

None

Light extinction coefficient - used with Beer’s Law for light absorption through plant canopies. See HCTN30 Eq.3.

JULES_PFTPARM::kpar_io

Type:

real(npft)

Default:

None

PAR Extinction coefficient (m² leaf / m² ground).

JULES_PFTPARM::lai_alb_lim_io

Type:

real(npft)

Default:

None

Minimum LAI permitted in calculation of the albedo in snow-free conditions.

JULES_PFTPARM::neff_io

Type:

real(npft)

Default:

None

Scale factor relating V_cmax with leaf nitrogen concentration. See HCTN 24 Eq. 51.

Only used if l_trait_phys = F.

JULES_PFTPARM::nl0_io

Type:

real(npft)

Default:

None

Top leaf nitrogen concentration (kg N/kg C).

Only used if l_trait_phys = F.

JULES_PFTPARM::nr_nl_io

Type:

real(npft)

Default:

None

Ratio of root nitrogen concentration to leaf nitrogen concentration.

JULES_PFTPARM::nr_io

Type:

real(npft)

Default:

None

Root nitrogen concentration (kgN/kgC). Only used if l_trait_phys = T.

JULES_PFTPARM::ns_nl_io

Type:

real(npft)

Default:

None

Ratio of stem nitrogen concentration to leaf nitrogen concentration.

JULES_PFTPARM::nsw_io

Type:

real(npft)

Default:

None

Stemwood nitrogen concentration (kgN/kgC). Only used if l_trait_phys = T.

JULES_PFTPARM::hw_sw_io

Type:

real(npft)

Default:

None

Ratio of Heartwood to Stemwood Nitrogen Concentration (typically 0.5) Only used if l_trait_phys = T.

JULES_PFTPARM::omega_io

Type:

real(npft)

Default:

None

Leaf scattering coefficient for PAR.

Always used unless can_rad_mod = 1 and l_spec_albedo = FALSE.

JULES_PFTPARM::omegau_io

Type:

real(npft)

Default:

None

Upper limit for the leaf scattering coefficient for PAR, when l_albedo_obs = TRUE and when omega_io is used.

JULES_PFTPARM::omegal_io

Type:

real(npft)

Default:

None

Lower limit for the leaf scattering coefficient for PAR, when l_albedo_obs = TRUE and when omega_io is used.

JULES_PFTPARM::omnir_io

Type:

real(npft)

Default:

None

Leaf scattering coefficient for NIR.

Always used unless can_rad_mod = 1 and l_spec_albedo = FALSE.

JULES_PFTPARM::omniru_io

Type:

real(npft)

Default:

None

Upper limit for the leaf scattering coefficient for NIR, when l_albedo_obs = TRUE and when omnir_io is used.

JULES_PFTPARM::omnirl_io

Type:

real(npft)

Default:

None

Lower limit for the leaf scattering coefficient for NIR, when l_albedo_obs = TRUE and when omnir_io is used.

JULES_PFTPARM::r_grow_io

Type:

real(npft)

Default:

None

Growth respiration fraction.

JULES_PFTPARM::fsmc_mod_io

Type:

integer(npft)

Default:

None

Switch for method of weighting the contribution that different soil layers make to the soil moisture availability factor fsmc.

0. (recommended) Calculate fsmc in each soil layer and take a weighted average, using the fraction of roots in each layer as weights. Root distribution e-folding depth is given by rootd_ft_io.

1. Calculate fsmc using average properties for the root zone. Depth of root zone is given by rootd_ft_io. This is not currently allowed if layered soil C (l_layeredc = TRUE) and the 4-pool model are selected (soil_bgc_model = 2) because of unplanned effects on litter inputs.

JULES_PFTPARM::psi_open_io

Type:

real(npft)

Default:

None

Soil potential above which the soil moisture stress factor on vegetation (fsmc) is one. Unit: Pa. Allowed range: must be negative. Only used if l_use_pft_psi = T.

JULES_PFTPARM::psi_close_io

Type:

real(npft)

Default:

None

Soil potential below which the soil moisture stress factor on vegetation (fsmc) is zero. Unit: Pa. Allowed range: must be negative. Only used if l_use_pft_psi = T.

JULES_PFTPARM::rootd_ft_io

Type:

real(npft)

Default:

None

Parameter determining the root depth (m).

If fsmc_mod_io = 0, an exponential root distribution with depth is assumed, with e-folding depth rootd_ft (see HCTN30 Eq.32). Note that this means that generally some of the roots exist at depths greater than rootd_ft. If fsmc_mod_io = 1, rootd_ft is the total depth of the root zone.

JULES_PFTPARM::fsmc_p0_io

Type:

real(npft)

Default:

None

Pft-dependent parameter governing the threshold at which the plant starts to experience water stress due to lack of water in the soil. Only used if l_use_pft_psi = F. The volumetric soil moisture content (m³ water per m³ soil) at which the plant starts to become water stressed is sm_wilt+(sm_crit-sm_wilt)*(1-fsmc_p0) (see JULES_SOIL_PROPS for a description of sm_wilt and sm_crit).

JULES_PFTPARM::sigl_io

Type:

real(npft)

Default:

None

Specific density of leaf carbon (kg C/m² leaf) (Clark et al., 2011; Table 7).

Only used if l_trait_phys = F.

JULES_PFTPARM::tleaf_of_io

Type:

real(npft)

Default:

None

Temperature below which leaves are dropped (K).

JULES_PFTPARM::tlow_io

Type:

real(npft)

Default:

None

Lower temperature parameter for photosynthesis (deg C), for the Collatz model of leaf photosynthesis.

Always used for C₄ plants. Only used for C₃ plants with the Collatz model of leaf photosynthesis (photo_model = 1).

JULES_PFTPARM::tupp_io

Type:

real(npft)

Default:

None

Upper temperature parameter for photosynthesis (deg C), for the Collatz model of leaf photosynthesis.

Always used for C₄ plants. Only used for C₃ plants with the Collatz model of leaf photosynthesis (photo_model = 1).

JULES_PFTPARM::emis_pft_io

Type:

real(npft)

Default:

None

Surface emissivity of vegetated surfaces.

JULES_PFTPARM::z0hm_pft_io

Type:

real(npft)

Default:

None

Ratio of the roughness length for heat to the roughness length for momentum.

This is generally assumed to be 0.1. See HCTN30 p6. Note that this is the ratio of the roughness length for heat to that for momentum. It does not alter the roughness length for momentum, which is calculated using canht_ft_io and dz0v_dh_io.

JULES_PFTPARM::z0hm_classic_pft_io

Type:

real(npft)

Default:

None

Ratio of the roughness length for heat to the roughness length for momentum for the CLASSIC aerosol scheme only.

Note

This makes no difference to the model when running standalone, and is only required to keep the standalone and UM interfaces consistent.

JULES_PFTPARM::fl_o3_ct_io

Type:

real(npft)

Default:

None

Critical flux of O3 to vegetation (nmol m^-2 s^-1).

JULES_PFTPARM::dfp_dcuo_io

Type:

real(npft)

Default:

None

Plant type specific O3 sensitivity parameter (nmol^-1 m² s).

JULES_PFTPARM::ief_io

Type:

real(npft)

Default:

None

Isoprene Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::tef_io

Type:

real(npft)

Default:

None

Monoterpene Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::mef_io

Type:

real(npft)

Default:

None

Methanol Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::aef_io

Type:

real(npft)

Default:

None

Acetone Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::ci_st_io

Tybe:

real(npft)

Default:

None

Leaf-internal CO₂concentration at standard conditions (Pa),

Note

Standard conditions are: T = 303.15K, p = 1013.25 hPa, atmospheric CO₂ = 370 ppmv, PAR = 1000 μmol m^-2 s^-1.

JULES_PFTPARM::gpp_st_io

Tybe:

real(npft)

Default:

None

Gross primary production (GPP) at standard conditions (kgC m^-2 s^-1),

Note

Standard conditions are: T = 303.15K, p = 1013.25 hPa, atmospheric CO₂ = 370 ppmv, PAR = 1000 μmol m^-2 s^-1.

JULES_PFTPARM::nmass_io

Type:

real(npft)

Default:

None

Top leaf nitrogen content per unit mass (kgN kgLeaf^-1).

Only used if l_trait_phys = T.

JULES_PFTPARM::lma_io

Type:

real(npft)

Default:

None

Leaf mass per unit area (kgLeaf m^-2).

Only used if l_trait_phys = T.

JULES_PFTPARM::vint_io

Type:

real(npft)

Default:

None

There is a linear relationship between Vcmax and Narea. Previously Vcmax was calculated as the product of nl0 and neff.

This is now replaced by a linear regression based on data reported in Kattge et al. 2009. Vint is the y-intercept, vsl is the slope.

Units: μmol CO₂ m^-2 s^-1.

Only used if l_trait_phys = T.

JULES_PFTPARM::vsl_io

Type:

real(npft)

Default:

None

Slope in the linear regression between Vcmax and Narea.

Units: μmol CO₂ gN^-1 s^-1.

Only used if l_trait_phys = T.

JULES_PFTPARM::kn_io

Type:

real(npft)

Default:

None.

Parameter for decay of nitrogen through the canopy, as a function of layers. Only used if can_rad_mod = 4 or 5.

JULES_PFTPARM::knl_io

Type:

real(npft)

Default:

None.

Parameter for decay of nitrogen through the canopy, as a function of LAI. Only used if can_rad_mod = 6.

JULES_PFTPARM::q10_leaf_io

Type:

real(npft)

Default:

None.

Q10 factor for plant respiration.

See Cox et al. (1999) Eq. 66.

Note

Was previously a single parameter but now can have PFT-dependent values.

JULES_PFTPARM::fef_co2_io

Type:

real(npft)

Default:

None

Fire CO₂ Emission Factor (g kg^-1).

JULES_PFTPARM::fef_co_io

Type:

real(npft)

Default:

None

Fire CO Emission Factor (g kg^-1).

JULES_PFTPARM::fef_ch4_io

Type:

real(npft)

Default:

None

Fire CH₄ Emission Factor (g kg^-1).

JULES_PFTPARM::fef_nox_io

Type:

real(npft)

Default:

None

Fire NOx Emission Factor (g kg^-1).

JULES_PFTPARM::fef_so2_io

Type:

real(npft)

Default:

None

Fire SO₂ Emission Factor (g kg^-1).

JULES_PFTPARM::fef_oc_io

Type:

real(npft)

Default:

None

Fire OC Emission Factor (g kg^-1).

JULES_PFTPARM::fef_bc_io

Type:

real(npft)

Default:

None

Fire BC Emission Factor (g kg^-1).

JULES_PFTPARM::ccleaf_min_io

Type:

real(npft)

Default:

None

Leaf minimum combustion completeness.

JULES_PFTPARM::ccleaf_max_io

Type:

real(npft)

Default:

None

Leaf maximum combustion completeness.

JULES_PFTPARM::ccwood_min_io

Type:

real(npft)

Default:

None

Wood minimum combustion completeness.

JULES_PFTPARM::ccwood_max_io

Type:

real(npft)

Default:

None

Wood maximum combustion completeness.

JULES_PFTPARM::avg_ba_io

Type:

real(npft)

Default:

None

Average PFT Burnt Area per fire (m²).

JULES_PFTPARM::fire_mort_io

Type:

real(npft)

Default:

None

Scaling factor for vegetation mortality caused by fire (from INFERNO burned area). Can be varied between 0.0 (no morality) and 1.0 (100% mortality) for each PFT.

See also

References:

• Clark et al., 2011, The Joint UK Land Environment Simulator (JULES), model description – Part 2: Carbon fluxes and vegetation dynamics, Geosci. Model Dev., 4, 701-722, https://doi.org/10.5194/gmd-4-701-2011

• Pinty, B., T. Lavergne, R. E. Dickinson, J.-L. Widlowski, N. Gobron, and M. M. Verstraete (2006), Simplifying the interaction of land surfaces with radiation for relating remote sensing products to climate models, J. Geophys. Res., 111, D02116, https://doi.org/10.1029/2005JD005952.

Only used with the Farquhar model of leaf photosynthesis (photo_model = 2). A value is required for each PFT, but only those for C₃ plants are used (since only C₃ plants use the Farquhar model). Below, J_max is the potential rate of electron transport, and V_cmax is the maximum rate of carboxylation of Rubisco.

JULES_PFTPARM::act_jmax_io

Type:

real(npft)

Default:

None

Activation energy for temperature response of J_max (J mol^-1).

JULES_PFTPARM::act_vcmax_io

Type:

real(npft)

Default:

None

Activation energy for temperature response of V_cmax (J mol^-1).

Note

act_jmax_io and act_vcmax_io are NOT required if thermal adaptation or acclimation of photosynthesis is selected (photo_acclim_model = 1, 2 or 3) together with photo_act_model = 2.

JULES_PFTPARM::alpha_elec_io

Type:

real(npft)

Default:

None

Quantum yield of electron transport (mol electrons [mol^-1 PAR photons]).

JULES_PFTPARM::deact_jmax_io

Type:

real(npft)

Default:

None

Deactivation energy for temperature response of J_max (J mol^-1). This describes the rate of decrease above the optimum temperature.

JULES_PFTPARM::deact_vcmax_io

Type:

real(npft)

Default:

None

Deactivation energy for temperature response of V_cmax (J mol^-1). This describes the rate of decrease above the optimum temperature.

JULES_PFTPARM::jv25_ratio_io

Type:

real(npft)

Default:

None

Ratio of J_max to V_cmax at 25 deg C (mol electrons [mol^-1 CO₂]).

Note

If thermal adaptation or acclimation of photosynthesis is selected (photo_acclim_model = 1 or 2) together with photo_jv_model =2 (J_max/V_cmax calculated assuming constant total nitrogen allocation)), this value is used along with parameters n_alloc_jmax and n_alloc_vcmax to calculate the final value of J_max/V_cmax.

Only used if thermal adaptation or acclimation of photosynthetic capacity is NOT modelled (photo_acclim_model = 0). A value is required for each PFT, but only those for C₃ plants are used (since only C₃ plants use the Farquhar model).

JULES_PFTPARM::ds_jmax_io

Type:

real(npft)

Default:

None

Entropy factor for temperature reponse of J_max (J mol^-1 K^-1).

JULES_PFTPARM::ds_vcmax_io

Type:

real(npft)

Default:

None

Entropy factor for temperature reponse of V_cmax (J mol^-1 K^-1).