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Grass PFT only creates leaves not cwd
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In response to issue #884

Modified EDCohortDynamicsMod.F90 (@ln970): if the pft is grass then all of its organs are treated as leaves for calculation of coarse woody debris(cwd).
EDPatchDynamicsMod.F90 (@ln 1641):  When patches spawn, only tree pft donate dead tress or cwd, and mass to the new patch, if pft is grass it assumed that grass was consumed in fire. This may not resolve fluxes to the atmosphere accurately.
EDPhysiologyMod.F90 (@ln 2199):  When other litter fluxes occur, if pft is grass, then it only turnsover  or contributes leaves not coarse woody debris.
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@ZacharyRobbins
ZacharyRobbins committed Aug 16, 2022
1 parent f812ecc commit 0d6527d
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Showing 3 changed files with 76 additions and 37 deletions.
26 changes: 20 additions & 6 deletions biogeochem/EDCohortDynamicsMod.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -967,12 +967,26 @@ subroutine SendCohortToLitter(csite,cpatch,ccohort,nplant,bc_in)

do el=1,num_elements

leaf_m = ccohort%prt%GetState(leaf_organ, element_list(el))
store_m = ccohort%prt%GetState(store_organ, element_list(el))
sapw_m = ccohort%prt%GetState(sapw_organ, element_list(el))
fnrt_m = ccohort%prt%GetState(fnrt_organ, element_list(el))
struct_m = ccohort%prt%GetState(struct_organ, element_list(el))
repro_m = ccohort%prt%GetState(repro_organ, element_list(el))
if ( prt_params%woody(pft) == itrue) then !trees only
leaf_m = ccohort%prt%GetState(leaf_organ, element_list(el))
store_m = ccohort%prt%GetState(store_organ, element_list(el))
sapw_m = ccohort%prt%GetState(sapw_organ, element_list(el))
fnrt_m = ccohort%prt%GetState(fnrt_organ, element_list(el))
struct_m = ccohort%prt%GetState(struct_organ, element_list(el))
repro_m = ccohort%prt%GetState(repro_organ, element_list(el))
else
leaf_m = ccohort%prt%GetState(leaf_organ, element_list(el))+ &
ccohort%prt%GetState(store_organ, element_list(el))+ &
ccohort%prt%GetState(sapw_organ, element_list(el))+ &
ccohort%prt%GetState(fnrt_organ, element_list(el))+ &
ccohort%prt%GetState(struct_organ, element_list(el))+ &
ccohort%prt%GetState(repro_organ, element_list(el))
store_m = 0_r8
sapw_m = 0_r8
fnrt_m = 0_r8
struct_m = 0_r8
repro_m = 0_r8
end if

litt => cpatch%litter(el)
flux_diags => csite%flux_diags(el)
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33 changes: 18 additions & 15 deletions biogeochem/EDPatchDynamicsMod.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -1637,13 +1637,17 @@ subroutine fire_litter_fluxes(currentSite, currentPatch, &
! across ground surface.
! -----------------------------------------------------------------------

sapw_m = currentCohort%prt%GetState(sapw_organ, element_id)
struct_m = currentCohort%prt%GetState(struct_organ, element_id)
leaf_m = currentCohort%prt%GetState(leaf_organ, element_id)
fnrt_m = currentCohort%prt%GetState(fnrt_organ, element_id)
store_m = currentCohort%prt%GetState(store_organ, element_id)
repro_m = currentCohort%prt%GetState(repro_organ, element_id)

if ( prt_params%woody(pft) == itrue) then !trees only, May require additional accounting for the atm_fluxes when PFT is grass.
! Goal was to not add to pools in the event of grass fire. Grass would typically not introduce a flux of dead leaves
! or coarse woody debris. This may be too coarse a solution in the long term.
leaf_m = currentCohort%prt%GetState(leaf_organ, element_list(el))
store_m = currentCohort%prt%GetState(store_organ, element_list(el))
sapw_m = currentCohort%prt%GetState(sapw_organ, element_list(el))
fnrt_m = currentCohort%prt%GetState(fnrt_organ, element_list(el))
struct_m = currentCohort%prt%GetState(struct_organ, element_list(el))
repro_m = currentCohort%prt%GetState(repro_organ, element_list(el))


! Absolute number of dead trees being transfered in with the donated area
num_dead_trees = (currentCohort%fire_mort*currentCohort%n * &
patch_site_areadis/currentPatch%area)
Expand All @@ -1654,7 +1658,7 @@ subroutine fire_litter_fluxes(currentSite, currentPatch, &

! Contribution of dead trees to leaf burn-flux
burned_mass = num_dead_trees * (leaf_m+repro_m) * currentCohort%fraction_crown_burned

do dcmpy=1,ndcmpy
dcmpy_frac = GetDecompyFrac(pft,leaf_organ,dcmpy)
new_litt%leaf_fines(dcmpy) = new_litt%leaf_fines(dcmpy) + &
Expand All @@ -1667,9 +1671,7 @@ subroutine fire_litter_fluxes(currentSite, currentPatch, &

call set_root_fraction(currentSite%rootfrac_scr, pft, currentSite%zi_soil, &
bc_in%max_rooting_depth_index_col)

! Contribution of dead trees to root litter (no root burn flux to atm)
do dcmpy=1,ndcmpy
do dcmpy=1,ndcmpy
dcmpy_frac = GetDecompyFrac(pft,fnrt_organ,dcmpy)
do sl = 1,currentSite%nlevsoil
donatable_mass = num_dead_trees * (fnrt_m+store_m) * currentSite%rootfrac_scr(sl)
Expand All @@ -1688,10 +1690,10 @@ subroutine fire_litter_fluxes(currentSite, currentPatch, &
flux_diags%root_litter_input(pft) = &
flux_diags%root_litter_input(pft) + &
(fnrt_m + store_m) * num_dead_trees

! coarse root biomass per tree
bcroot = (sapw_m + struct_m) * (1.0_r8 - prt_params%allom_agb_frac(pft) )

! below ground coarse woody debris from burned trees
do c = 1,ncwd
do sl = 1,currentSite%nlevsoil
Expand Down Expand Up @@ -1719,14 +1721,15 @@ subroutine fire_litter_fluxes(currentSite, currentPatch, &
donatable_mass = num_dead_trees * SF_val_CWD_frac(c) * bstem
if (c == 1 .or. c == 2) then
donatable_mass = donatable_mass * (1.0_r8-currentCohort%fraction_crown_burned)
burned_mass = num_dead_trees * SF_val_CWD_frac(c) * bstem * &
burned_mass = num_dead_trees * SF_val_CWD_frac(c) * bstem * &
currentCohort%fraction_crown_burned
site_mass%burn_flux_to_atm = site_mass%burn_flux_to_atm + burned_mass
endif
new_litt%ag_cwd(c) = new_litt%ag_cwd(c) + donatable_mass * donate_m2
curr_litt%ag_cwd(c) = curr_litt%ag_cwd(c) + donatable_mass * retain_m2
flux_diags%cwd_ag_input(c) = flux_diags%cwd_ag_input(c) + donatable_mass
enddo
enddo
endif


currentCohort => currentCohort%taller
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54 changes: 38 additions & 16 deletions biogeochem/EDPhysiologyMod.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -2193,24 +2193,46 @@ subroutine CWDInput( currentSite, currentPatch, litt, bc_in)
currentCohort => currentPatch%shortest
do while(associated(currentCohort))
pft = currentCohort%pft

call set_root_fraction(currentSite%rootfrac_scr, pft, currentSite%zi_soil, &
call set_root_fraction(currentSite%rootfrac_scr, pft, currentSite%zi_soil, &
bc_in%max_rooting_depth_index_col)

leaf_m_turnover = currentCohort%prt%GetTurnover(leaf_organ,element_id)
store_m_turnover = currentCohort%prt%GetTurnover(store_organ,element_id)
fnrt_m_turnover = currentCohort%prt%GetTurnover(fnrt_organ,element_id)
sapw_m_turnover = currentCohort%prt%GetTurnover(sapw_organ,element_id)
struct_m_turnover = currentCohort%prt%GetTurnover(struct_organ,element_id)
repro_m_turnover = currentCohort%prt%GetTurnover(repro_organ,element_id)

leaf_m = currentCohort%prt%GetState(leaf_organ,element_id)
store_m = currentCohort%prt%GetState(store_organ,element_id)
fnrt_m = currentCohort%prt%GetState(fnrt_organ,element_id)
sapw_m = currentCohort%prt%GetState(sapw_organ,element_id)
struct_m = currentCohort%prt%GetState(struct_organ,element_id)
repro_m = currentCohort%prt%GetState(repro_organ,element_id)

if ( prt_params%woody(pft) == itrue) then !trees only
leaf_m_turnover = currentCohort%prt%GetTurnover(leaf_organ, element_id)
store_m_turnover = currentCohort%prt%GetTurnover(store_organ,element_id)
sapw_m_turnover = currentCohort%prt%GetTurnover(sapw_organ, element_id)
fnrt_m_turnover = currentCohort%prt%GetTurnover(fnrt_organ, element_id)
struct_m_turnover = currentCohort%prt%GetTurnover(struct_organ, element_id)
repro_m_turnover = currentCohort%prt%GetTurnover(repro_organ, element_id)
leaf_m = currentCohort%prt%GetState(leaf_organ, element_id)
store_m = currentCohort%prt%GetState(store_organ, element_id)
sapw_m = currentCohort%prt%GetState(sapw_organ, element_id)
fnrt_m = currentCohort%prt%GetState(fnrt_organ, element_id)
struct_m = currentCohort%prt%GetState(struct_organ, element_id)
repro_m = currentCohort%prt%GetState(repro_organ, element_id)
else ! grass PFTs should not spawn anything other than leaves.
leaf_m_turnover = currentCohort%prt%GetTurnover(leaf_organ, element_id)+ &
currentCohort%prt%GetTurnover(store_organ, element_id)+ &
currentCohort%prt%GetTurnover(sapw_organ, element_id)+ &
currentCohort%prt%GetTurnover(fnrt_organ, element_id)+ &
currentCohort%prt%GetTurnover(struct_organ, element_id)+ &
currentCohort%prt%GetTurnover(repro_organ, element_id)
store_m_turnover = 0_r8
sapw_m_turnover = 0_r8
fnrt_m_turnover = 0_r8
struct_m_turnover = 0_r8
repro_m_turnover = 0_r8
leaf_m = currentCohort%prt%GetState(leaf_organ, element_id)+ &
currentCohort%prt%GetState(store_organ, element_id)+ &
currentCohort%prt%GetState(sapw_organ, element_id)+ &
currentCohort%prt%GetState(fnrt_organ, element_id)+ &
currentCohort%prt%GetState(struct_organ, element_id)+ &
currentCohort%prt%GetState(repro_organ, element_id)
store_m = 0_r8
sapw_m = 0_r8
fnrt_m = 0_r8
struct_m = 0_r8
repro_m = 0_r8
end if
plant_dens = currentCohort%n/currentPatch%area

! ---------------------------------------------------------------------------------
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