#if defined(L19_2A) ! *****************************COPYRIGHT******************************* ! (C) Crown copyright Met Office. All rights reserved. ! For further details please refer to the file COPYRIGHT.txt ! which you should have received as part of this distribution. ! *****************************COPYRIGHT******************************* ! Subroutine VEGCARB ------------------------------------------------ ! ! Purpose : Updates carbon contents of the vegetation. ! ! ------------------------------------------------------------------- SUBROUTINE vegcarb (land_pts,trif_pts,trif_index & , n,forw,GAMMA,g_leaf,npp,resp_w & , leaf,root,wood,dcveg,pc_s) USE pftparm USE trif USE parkind1, ONLY: jprb, jpim USE yomhook, ONLY: lhook, dr_hook IMPLICIT NONE INTEGER & land_pts & ! IN Total number of land points. ,trif_pts & ! IN Number of points on which ! ! TRIFFID may operate ,trif_index(land_pts) & ! IN Indices of land points on ! ! which TRIFFID may operate ,n & ! IN Plant functional type. ,l,t ! WORK Loop counters REAL & forw & ! IN Forward timestep weighting. ,GAMMA & ! IN Inverse timestep (/360days). ,g_leaf(land_pts) & ! IN Turnover rate for leaf and ! ! fine root biomass (/360days). ,npp(land_pts) & ! INOUT Net primary productivity ! ! (kg C/m2/360days). ,resp_w(land_pts) & ! INOUT Wood maintenance respiration ! ! (kg C/m2/360days). ,leaf(land_pts) & ! INOUT Leaf biomass (kg C/m2). ,root(land_pts) & ! INOUT Root biomass (kg C/m2). ,wood(land_pts) & ! INOUT Woody biomass (kg C/m2). ,dcveg(land_pts) & ! OUT Change in vegetation carbon ! ! during the timestep ! ! (kg C/m2/timestep). ,pc_s(land_pts) & ! OUT Net carbon flux available ! ! for spreading (kg C/m2/360days). ,dfpar_dlai & ! WORK Rate of change of FPAR ! ! with leaf area index. ,dlai & ! WORK Increment to the leaf area ! ! index. ,dlamg_dlai,dlit_dlai & ! WORK Required for calculation ! ! of the equilibrium increments. ,dnpp_dlai(land_pts) & ! WORK Rate of change of NPP ! ! with leaf area index ! ! (kg C/m2/360days/LAI). ,dpc_dlai(land_pts) & ! WORK Rate of change of PC ! ! with leaf area index ! ! (kg C/m2/360days/LAI). ,dpcg_dlai(land_pts) & ! WORK Rate of change of PC_G ! ! with leaf area index ! ! (kg C/m2/360days/LAI). ,drespw_dlai & ! WORK Rate of change of RESP_W ! ! with leaf area index ,fpar & ! WORK PAR interception factor. ,lai(land_pts) & ! WORK Leaf area index. ,lambda_g & ! WORK Fraction of NPP available ! ! for spreading. ,lit_c_l(land_pts) & ! WORK Local rate of Carbon Litter ! ! production (kg C/m2/360days). ,pc(land_pts) & ! WORK Net carbon flux available ! ! to vegetation (kg C/m2/360days) ,pc_g(land_pts) ! WORK Net carbon flux available ! ! for growth (kg C/m2/360days). INTEGER(KIND=jpim), PARAMETER :: zhook_in = 0 INTEGER(KIND=jpim), PARAMETER :: zhook_out = 1 REAL(KIND=jprb) :: zhook_handle IF (lhook) CALL dr_hook('VEGCARB',zhook_in,zhook_handle) DO t=1,trif_pts l=trif_index(t) lai(l) = leaf(l)/sigl(n) !---------------------------------------------------------------------- ! Calculate the local production rate for carbon litter !---------------------------------------------------------------------- lit_c_l(l) = g_leaf(l)*leaf(l)+g_root(n)*root(l) & + g_wood(n)*wood(l) !---------------------------------------------------------------------- ! Diagnose the net local carbon flux into the vegetation !---------------------------------------------------------------------- pc(l) = npp(l) - lit_c_l(l) !---------------------------------------------------------------------- ! Variables required for the implicit and equilibrium calculations !---------------------------------------------------------------------- dlit_dlai = (g_leaf(l)*leaf(l)+g_root(n)*root(l))/lai(l) & + b_wl(n)*g_wood(n)*wood(l)/lai(l) fpar = (1 - EXP(-kpar(n)*lai(l)))/kpar(n) dfpar_dlai = EXP(-kpar(n)*lai(l)) dnpp_dlai(l) = npp(l)*dfpar_dlai/fpar & + (1-r_grow(n))*resp_w(l) & *(dfpar_dlai/fpar-b_wl(n)/lai(l)) lambda_g = 1 - (lai(l) - lai_min(n)) & /(lai_max(n) - lai_min(n)) dlamg_dlai = -1.0/(lai_max(n) - lai_min(n)) pc_g(l) = lambda_g * npp(l) - lit_c_l(l) dpcg_dlai(l) = lambda_g*dnpp_dlai(l) & + dlamg_dlai*npp(l) & - dlit_dlai dpc_dlai(l) = dnpp_dlai(l) - dlit_dlai END DO !---------------------------------------------------------------------- ! Update vegetation carbon contents !---------------------------------------------------------------------- DO t=1,trif_pts l=trif_index(t) dcveg(l) = leaf(l)+root(l)+wood(l) END DO ! DEPENDS ON: growth CALL growth (land_pts,trif_pts,trif_index & , n,dpcg_dlai,forw,GAMMA,pc_g,leaf,root,wood) DO t=1,trif_pts l=trif_index(t) dcveg(l) = leaf(l)+root(l)+wood(l)-dcveg(l) END DO !---------------------------------------------------------------------- ! Diagnose the carbon available for spreading and apply implicit ! corrections to the driving fluxes. !---------------------------------------------------------------------- DO t=1,trif_pts l=trif_index(t) dlai = leaf(l)/sigl(n) - lai(l) pc_s(l) = pc(l) + forw*dpc_dlai(l)*dlai - dcveg(l)*GAMMA fpar = (1 - EXP(-kpar(n)*lai(l)))/kpar(n) dfpar_dlai = EXP(-kpar(n)*lai(l)) drespw_dlai = resp_w(l)*b_wl(n)/lai(l) npp(l) = npp(l) + forw*dnpp_dlai(l)*dlai resp_w(l) = resp_w(l) + forw*drespw_dlai*dlai END DO IF (lhook) CALL dr_hook('VEGCARB',zhook_out,zhook_handle) RETURN END SUBROUTINE vegcarb #endif