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!*****************************************************************!
!* *!
!* 4C (FORESEE) *!
!* *!
!* *!
!* Subroutines for: *!
!* Calculation of daily NPP *!
!* *!
!* SR OPT_PS: optimum photosynthesis & conductance calculation *!
!* SR NPP: determination of realized net primary production *!
!* *!
!* Copyright (C) 1996-2018 *!
!* Potsdam Institute for Climate Impact Reserach (PIK) *!
!* Authors and contributors see AUTHOR file *!
!* This file is part of 4C and is licensed under BSD-2-Clause *!
!* See LICENSE file or under: *!
!* http://www.https://opensource.org/licenses/BSD-2-Clause *!
!* Contact: *!
!* https://gitlab.pik-potsdam.de/foresee/4C *!
!* *!
!*****************************************************************!
!***********************!
!* SUBROUTINE OPT_PS *!
!***********************!
! calculates optimum photosynthesis following Haxeltine & Prentice (1996)
SUBROUTINE OPT_PS(temp, dayl, PAR, ApPa)
!*** Declaration part ***!
USE data_species
USE data_stand
USE data_simul
USE data_climate
USE data_par
IMPLICIT NONE
! input variables
REAL :: temp, & ! temperature
dayl, & ! day length
PAR ! total available PAR
! auxiliary variables
REAL :: ApPa, & ! atmospheric pressure [Pa], input [hPa]
VmOpt = 0., &
VmMax = 0., & ! nitrogen limited carboxylation rate
Jc = 0., & ! Rubisco limited rate of photosynthesis
Je = 0., & ! photosynthetic response under light limitation
assiSpe = 0., & ! specific gross photosynthesis [gC m-2 canopy projection d-1]
respSpe = 0., & ! specific leaf respiration [gC m-2 canopy projection d-1]
assDt, & ! net daytime assimilation rate
PHIT = 0., &
XHELP = 0., &
kco2, &
ko2, &
tau, & ! Rubisco specificity
piCO2, & ! leaf internal CO2 partial pressure [Pa]
gammas, & ! CO2 compensation point in absence of mitochondrial respiration [Pa]
delta, &
sigma, &
c1, &
c2, &
vmspe, &
redn_h, &
h_age
! variables required for technical reasons
! INTEGER :: nl ! loop variable for crown layers
integer ntr, i, j
TYPE(coh_obj), POINTER :: p
!*** Calculation part ***!
! conversion of pressure from [kPa] to [P]
ApPa = ApPa * 100. ! hPa ==> Pa
! initialization of canopy conductance
gp_can = 0.
gp_tot = 0.
phot_C=0.
! polar night
if (dayl .lt. zero) then
p => pt%first
DO WHILE (ASSOCIATED(p))
p%coh%LUE = 0.0
p%coh%assi = 0.0
p%coh%resp = 0.0
p%coh%gp = 0.0
p%coh%Ndemc_d = 0.0
p => p%next
enddo
return
endif
! Determination of photosynthesis nitrogen reduction factor RedN for species
select case (flag_limi)
case (11)
do j=1,anrspec
i = nrspec(j)
redn_h = svar(i)%RedN
if(svar(i)%Ndem .gt. 0) then
svar(i)%RedN = svar(i)%Nupt / svar(i)%Ndem
if (svar(i)%RedN .gt. 1.) svar(i)%RedN=1.
else
svar(i)%RedN = redn_h
endif
enddo
case (12)
do j=1,anrspec
i = nrspec(j)
redn_h = svar(i)%RedN
if(svar(i)%Ndem .gt. 0) then
if (svar(i)%Nupt .gt. svar(i)%Ndem) then
svar(i)%RedN = 1
else
svar(i)%RedN = exp((svar(i)%Nupt / svar(i)%Ndem) -1.)
endif
else
svar(i)%RedN = redn_h
endif
enddo
case (13,14)
do j=1,anrspec
i = nrspec(j)
redn_h = svar(i)%RedN
if(svar(i)%Ndem .gt. 0) then
xhelp = svar(i)%Nupt / svar(i)%Ndem
svar(i)%RedN = 2.*(xhelp+0.01) / (xhelp+1.)
else
svar(i)%RedN = redn_h
endif
if(svar(i)%Nupt .le. zero) svar(i)%RedN = redn_h
enddo
case (15)
do j=1,anrspec
i = nrspec(j)
redn_h = svar(i)%RedN
if(svar(i)%Ndem .gt. zero) then
xhelp = svar(i)%Nupt / svar(i)%Ndem
select case (i)
case (3) ! pine
if (xhelp .gt. 10.) then
svar(i)%RedN=1.
else
svar(i)%RedN = exp(xhelp -0.7) - 0.5
endif
case (10, 14) ! dougfir, ground vegetation
continue ! annual calculation in RedN_calc
case default
svar(i)%RedN = 2.*(xhelp+0.01) / (xhelp+1.)
end select
if (svar(i)%RedN .gt. 1.) svar(i)%RedN=1.
if (svar(i)%RedN .lt. 0.1) svar(i)%RedN=0.1
else
svar(i)%RedN = redn_h
endif
if(svar(i)%Nupt .le. zero) svar(i)%RedN = redn_h
if (i.eq.nspec_tree+2) then
svar(i)%RedN=1.
endif
enddo
case (16)
svar%Ndemp = -1.*svar%Ndemp
svar%Nuptp = -1.*svar%Nuptp
zeig => pt%first
DO WHILE (ASSOCIATED(zeig))
ns = zeig%coh%species
ntr = zeig%coh%ntreea
svar(ns)%Ndemp = svar(ns)%Ndemp + ntr * zeig%coh%Ndemc_c
svar(ns)%Nuptp = svar(ns)%Nuptp + ntr * zeig%coh%Nuptc_c
zeig => zeig%next
ENDDO
do j=1,anrspec
i = nrspec(j)
redn_h = svar(i)%RedN
if(svar(i)%Ndemp .gt. 0) then
svar(i)%RedN = svar(i)%Nuptp / svar(i)%Ndemp
else
svar(i)%RedN = redn_h
endif
enddo
end select ! flag_limi
! internal partial pressure of CO2 (Eq A9)
piCO2 = ApPa * lambda * CO2
! temperature dependent damping function; orig pars: 0.2, 10.
PHIT = 1. / ( 1.+exp(0.4*(7.-temp)) )
! loop over all cohorts
p => pt%first
DO WHILE (ASSOCIATED(p))
ns = p%coh%species
! parameter variations with temperature (Eq A14)
KCO2 = spar(ns)%kCO2_25 * spar(ns)%q10_kCO2 ** ( (temp - 25.) / 10.)
KO2 = spar(ns)%kO2_25 * spar(ns)%q10_kO2 ** ( (temp - 25.) / 10.)
tau = spar(ns)%pc_25 * spar(ns)%q10_pc ** ( (temp - 25.) / 10.)
! CO2 compensation point in absence of mitochondrial respiration, O2 converted from kPa to Pa
gammas = O2*1000 / (2. * tau)
! slope for light response under PAR limitation (Eq A7)
C1 = PHIT*spar(ns)%phic*Cmass*QCO2*QCO2a * (piCO2 - gammas) / (piCO2 + 2.*gammas) ! 0.35
! slope for light response under Rubisco limitation (Eq A11)
C2 = (piCO2 - gammas) / ( piCO2 + KCO2 * (1. + O2 / KO2) )
! daylength-dependent term (original: s)
DELTA = (24. / dayL) * spar(ns)%pb
! optimal light use efficiency (Eq A17 and A17a)
SIGMA = AMAX1 (0.0001, 1. - (C2 - DELTA) / (C2 - PS * DELTA) ) ** 0.5 ! 0.25 - 0.45
VmSpe = (1. / spar(ns)%pb) * (C1 / C2) * ( (2.*PS - 1.) * &
DELTA - (2.*PS * DELTA - C2) * SIGMA)
! maximum carboxylation potential in gC m-2 d-1 ???
VmOpt = p%coh%totFPAR * PAR * VmSpe
! Determination of photosynthesis nitrogen reduction factor RedN
select case (flag_limi)
case (0,1)
p%coh%RedNc = 1.
case (2,3,10)
p%coh%RedNc = svar(ns)%RedN
case (4,5)
! N effect on photosynthesis
XHELP = PN * exp ( - 0.0693 * (temp - 25.) )
! calculate Vmax as function of metabolically active nitrogen per unit crown projection area first, is now in mymol m-2 s-1
VmMax = (p%coh%N_fol - Nc0*p%coh%x_fol) / p%coh%crown_area / XHELP
p%coh%RedNc = MIN (1., VmMax / VmOpt)
case (6,7)
if ((p%coh%Ndemc_d .gt. 1.E-6) .and. (p%coh%Nuptc_d .gt. 1.E-6)) then
p%coh%RedNc = p%coh%Nuptc_c / p%coh%Ndemc_c
else
p%coh%RedNc = svar(ns)%RedN
endif
case (8,9)
h_age = p%coh%x_age
if( h_age.lt.50.) then
redn_h =svar(ns)%RedN
else if( (h_age-time).lt.50) then
! age dependent reduction of redN
redn_h = svar(ns)%RedN*(1-max(0.,(h_age-50)*0.002))
else
redn_h = svar(ns)%RedN*(1-max(0.,(time)*0.002))
end if
p%coh%RedNc = redn_h
case (11,12,13,14,15,16) ! calculation of cohort loop
p%coh%RedNc = svar(p%coh%species)%RedN
end select
! limiting rates
Jc = C2 * VmSpe / 24.
Je = C1 / dayL
! gross assimilation and leaf respiration in [g C/(day*m2)]
p%coh%LUE = dayL * ( Je+Jc - SQRT( (Je+Jc) * (Je+Jc) - 4.*PS*Je*Jc) ) / (2.*PS) * p%coh%RedNc
assiSpe = p%coh%LUE * p%coh%totFPAR * PAR
if(p%coh%totFPAR.lt.0) then
continue
end if
respSpe = spar(ns)%pb * VmOpt * p%coh%RedNc
phot_C = phot_C + p%coh%ntreea*assiSpe !summation for output BE
p%coh%assi = assiSpe * kPatchSize / 1000. * (1/cpart) ! conversion g C/day*m2 -> kg DW/day*patch
p%coh%resp = respSpe * kPatchSize / 1000. * (1/cpart) ! conversion g C/day*m2 -> kg DW/day*patch
! optimum stomatal conductance (modified from Haxeltine & Prentice 1996) [mol/(m2*d)]
assDt = assiSpe - dayL/24.*respSpe
p%coh%gp = AMAX1( gmin, 1.56*assDt / (1.0-lambda) / CO2 / Cmass )
! update canopy conductance
IF (p%coh%species.le.nspec_tree .or. p%coh%species.eq.nspec_tree+2 ) then
gp_can = gp_can + p%coh%gp*p%coh%nTreeA
else
gp_tot = gp_tot + p%coh%gp*p%coh%nTreeA
endif
p => p%next
END DO
gp_tot = gp_tot + gp_can
END SUBROUTINE OPT_PS
!********************!
!* SUBROUTINE NPP *!
!********************!
! determines realized assimilation rate by taking into account water stress, and
! calculates growth and maintenance respiration, plus overall net primary production
SUBROUTINE NPP( temp, dayL, PAR, jx )
!*** Declaration part ***!
USE data_par
USE data_stand
USE data_species
USE data_simul
USE data_soil_cn
IMPLICIT NONE
! input variables
REAL:: temp, &
dayL, &
PAR
! auxiliary variables
REAL :: netAsspot, & ! daily potential (= no water and nutrient limitation) net assimilation rate [= dimension of p%coh%assi]
netAss, & ! daily net assimilation rate [= dimension of p%coh%assi]
maintResp, & ! daily maintenance respiration costs
dailypotNPP, & ! daily potential (= no water and nutrient limitation) net primary productivity per tree
dailyNPP, & ! daily net primary productivity per tree [gC tree-1]
drLimF, & ! drought factor limiting the assimilation rate
grass = 0, & ! gross daily assimilation rate
respfol, &
prms, &
prmr, &
NPP_mistletoe,& ! NPP of mistletoe
pq10, & ! q10 value for maint. respiration stem, fine root
help, presp
INTEGER :: jx ! time step length of PS/NPP model
TYPE(coh_obj), POINTER :: p
pq10=2.0
!*** Calculation part ***!
!extraction of theor. produced NPP of mistletoe cohort
p => pt%first
do while (associated(p))
if (p%coh%species.eq.nspec_tree+2) then
NPP_mistletoe=p%coh%NPP
NPP_demand_mistletoe=0.3*NPP_mistletoe ! NPP that mistletoe demands from host (30% heterotroph carbon gain (Richter 1992)
p%coh%NPP=0.7*NPP_mistletoe ! rest of NPP stays with mistletoe (autotroph)
end if
p => p%next
enddo
dailypotNPP_C=0.
dailyNPP_C=0.
dailyautresp_C = 0.
dailygrass_C = 0.
dailynetass_C = 0.
respr_day = 0.
dailyrespfol_C = 0.
! loop over all cohorts
p => pt%first
DO WHILE (ASSOCIATED(p))
! reduction of NPP of mistletoe infected tree cohort
if (p%coh%mistletoe.eq.1) then
p%coh%NPP = p%coh%NPP-NPP_demand_mistletoe
endif
ns = p%coh%species
IF ( p%coh%drIndPS .lt. 0.0 ) THEN
continue
endif
! drought index
IF ( p%coh%nDaysPS /= 0. ) THEN
p%coh%drIndPS = p%coh%drIndPS / p%coh%nDaysPS
ELSE
p%coh%drIndPS = 0. ! -> npp = 0
END IF
! limiting function
select case(flag_limi)
case(0,2,4,6,8,14)
drLimF = 1.0
case default
drLimF = p%coh%drIndPS
end select
! total net assimilation, maintenance respiration and NPP of this tree
if (p%coh%RedNc .gt. 1.E-6) then
netAsspot = (p%coh%assi - p%coh%resp) / p%coh%RedNc
else
netAsspot = 0.
endif
netAss = drLimF * (p%coh%assi - p%coh%resp)
grass = drLimF * p%coh%assi
p%coh%respfol = grass -netAss
respfol = p%coh%respfol
IF (flag_resp==1) THEN
! calculate temperature dependant rates
prmr=spar(ns)%prmr*pq10**((temp-15)/10)
prms=spar(ns)%prms*pq10**((temp-15)/10)
! leaf maintenance respiration added
maintResp = prms * p%coh%x_sap + prmr * p%coh%x_frt + respfol
! for complete outputs of respiration components:
p%coh%respsap = prms * p%coh%x_sap
p%coh%respfrt = prmr * p%coh%x_frt
p%coh%respbr = prms * p%coh%x_tb
dailypotNPP = (1.-spar(ns)%prg) * (netAsspot - maintResp)
dailyNPP = (1.-spar(ns)%prg) * (netAss - maintResp)
help = spar(ns)%prg * (netAss - maintResp)
ELSEIF (flag_resp==2) THEN
presp=0.03
maintResp = (p%coh%x_sap*cpart/spar(ns)%cnr_stem + p%coh%x_crt*cpart/spar(ns)%cnr_crt + p%coh%x_tb*cpart/spar(ns)%cnr_tbc + p%coh%x_frt*cpart/spar(ns)%cnr_frt)*presp
maintresp=maintresp*exp(308.56*((1/56.02)-(1/(temp+46.02))))
dailypotNPP = (1.-spar(ns)%prg) * (netAsspot - maintResp)
dailyNPP = (1.-spar(ns)%prg) * (netAss - maintResp)
ELSE
dailypotNPP=netAsspot*(1-spar(ns)%respcoeff)
dailyNPP=netAss*(1-spar(ns)%respcoeff)
maintResp = netAss*spar(ns)%respcoeff
ENDIF
IF(p%coh%species <= nspec_tree) THEN
dailypotNPP_C = dailypotNPP_C + p%coh%ntreea*dailypotNPP*cpart*kg_in_g / (kPatchSize) !conversion in gC/m2
dailyNPP_C = dailyNPP_C + p%coh%ntreea*dailyNPP*cpart*kg_in_g / (kPatchSize) !conversion in gC/m2
if (flag_resp.eq.1) then
dailyautresp_C = dailyautresp_C + p%coh%ntreea*(maintresp+help)*cpart*kg_in_g / (kPatchSize)
ELSE ! flag_resp=0
dailyautresp_C = dailyautresp_C + p%coh%ntreea*(respfol+maintresp)*cpart*kg_in_g / (kPatchSize)
end if
dailygrass_C = dailygrass_C + p%coh%ntreea*grass*cpart*kg_in_g / (kPatchSize)
dailynetass_C = dailynetass_C + p%coh%ntreea*netass*cpart*kg_in_g / (kPatchSize)
dailyrespfol_C = dailyrespfol_C + p%coh%ntreea*respfol*cpart*kg_in_g / (kPatchSize)
ENDIF
if (dailyNPP .gt. 10000.) then
continue
end if
! update annual net assimilation and NPP sum
p%coh%netAss = p%coh%netAss + netAss * jx
p%coh%grossass = p%coh%grossass + grass * jx
if (flag_resp.eq.1)then
p%coh%maintres = p%coh%maintres + (maintresp + help) * jx
else
p%coh%maintres = p%coh%maintres + (maintresp + respfol) * jx
end if
select case (flag_dis) !phloem disturbance
case (1,2)
dailyNPP = dailyNPP * phlo_feed
case (0)
dailyNPP = dailyNPP
end select
p%coh%NPP = p%coh%NPP + dailyNPP * jx
p%coh%weekNPP = dailyNPP * jx
IF (time_out .gt. 0 .and. flag_cohout .eq. 2) THEN
CALL OUT_ASS( p%coh%ident, PAR, p%coh%NPP, p%coh%totFPAR, p%coh%LUE, p%coh%netAss, p%coh%grossass, p%coh%nDaysPS)
ENDIF
! remove Mistletoe from N demand calculation
if (p%coh%species.ne.nspec_tree+2) then
p%coh%Ndemc_d=dailyNPP*1000.*spar(ns)%pcnr
end if
IF((flag_limi==4 .OR. flag_limi==5) .AND. 1. > p%coh%RedNc .AND. &
p%coh%N_fol/p%coh%t_leaf <= 4.5 .AND. p%coh%N_pool > 0.) THEN
IF(p%coh%N_pool > p%coh%N_fol*(1./p%coh%RedNc - 1.)) THEN
p%coh%N_fol = p%coh%N_fol / p%coh%RedNc
p%coh%N_pool = p%coh%N_pool - p%coh%N_fol*(1./p%coh%RedNc - 1.)
ELSE
p%coh%N_fol = p%coh%N_fol + p%coh%N_pool
p%coh%N_pool = 0.0
ENDIF
ENDIF
p => p%next
END DO
END SUBROUTINE NPP