ESCOMP · slevis-lmwg · May 15, 2025 · Feb 18, 2022 · Feb 18, 2022 · Feb 18, 2022
diff --git a/cime_config/testdefs/testlist_clm.xml b/cime_config/testdefs/testlist_clm.xml
@@ -1202,6 +1202,15 @@
       <option name="comment">Smoke test of soil CN-matrix on with soil CN ratio set to 30</option>
     </options>
   </test>
+  <test name="SMS_Lm1" grid="f10_f10_mg37" compset="IHistClm60Bgc" testmods="clm/leafcn_t_evolving">
+    <machines>
+      <machine name="derecho" compiler="intel" category="aux_clm"/>
+    </machines>
+    <options>
+      <option name="wallclock">01:20:00</option>
+      <option name="comment">Smoke test using custom paramfile with leafcn_co2_slope set to 30 (default = 0). This confirms that the calculation of leafcn_t_evolving does not fail.</option>
+    </options>
+  </test>
   <test name="ERS_D" grid="f19_g17" compset="I1850Clm50BgcCrop" testmods="clm/ciso_monthly_matrixcn_spinup">
     <machines>
       <machine name="derecho" compiler="intel" category="aux_clm"/>

diff --git a/cime_config/testdefs/testmods_dirs/clm/ciso_cwd_hr/README b/cime_config/testdefs/testmods_dirs/clm/ciso_cwd_hr/README
@@ -1,8 +1,12 @@
 This points to an alternate params file with
-rf_cwdl2     = 0.5
-rf_cwdl3_bgc = 0.5
-while by default these parameters equal zero.
+ceta = 450 (default = 358)
 
+The README used to say that the alternate paramfile contained
+rf_cwdl2     = 0.5 (default 0)
+rf_cwdl3_bgc = 0.5 (default 0)
+but now 0.5 is the default.
+
+The README also used to say:
 The test outputs inactive history fields that would contain zeros
 when running with the default params file and should be greater than zero
 when running with the alternate params file.
diff --git a/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/README b/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/README
@@ -0,0 +1,6 @@
+This points to an alternate params file with
+leafcn_co2_slope = 30 (default = 0)
+to confirm that the leafcn_t_evolving calculation doesn't fail.
+
+When we added this test, slevis and ekluzek agreed to consolidate our custom paramfiles into one.
+The first of the consolidated paramfiles is named ctsm60_ceta450_cn30_co2_slope30.c250326.nc.
diff --git a/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/include_user_mods b/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/include_user_mods
@@ -0,0 +1 @@
+../default
diff --git a/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/user_nl_clm b/cime_config/testdefs/testmods_dirs/clm/leafcn_t_evolving/user_nl_clm
@@ -0,0 +1 @@
+paramfile = '$DIN_LOC_ROOT/lnd/clm2/paramdata/ctsm60_ceta450_cn30_co2_slope30.c250326.nc'
diff --git a/doc/ChangeLog b/doc/ChangeLog
@@ -1,4 +1,64 @@
 ===============================================================
+Tag name: ctsm5.3.044
+Originator(s): slevis (Samuel Levis,UCAR/TSS,303-665-1310)
+Date: Wed 14 May 2025 11:42:41 AM MDT
+One-line Summary: Introduce time-evolving LEAFCN_TARGET as function of leafcn param
+
+Purpose and description of changes
+----------------------------------
+
+ Motivated by a phd student's project (Emma Hauser, now Professor at UW-Madison) we have introduced time-evolving leafcn as a possible template for other time-evolving parameters.
+
+Significant changes to scientifically-supported configurations
+--------------------------------------------------------------
+
+Does this tag change answers significantly for any of the following physics configurations?
+(Details of any changes will be given in the "Answer changes" section below.)
+
+    [Put an [X] in the box for any configuration with significant answer changes.]
+
+[ ] clm6_0
+
+[ ] clm5_0
+
+[ ] ctsm5_0-nwp
+
+[ ] clm4_5
+
+
+Bugs fixed
+----------
+List of CTSM issues fixed (include CTSM Issue # and description) [one per line]:
+ Resolves #1646 Time evolving parameterization for leaf properties
+
+Notes of particular relevance for developers:
+---------------------------------------------
+Changes to tests or testing:
+ New test in aux_clm that points to an alternate params file with leafcn_co2_slope = 30 (default = 0) to confirm that the leafcn_t_evolving calculation doesn't fail
+
+Testing summary:
+----------------
+
+ [PASS means all tests PASS; OK means tests PASS other than expected fails.]
+
+  regular tests (aux_clm: https://github.com/ESCOMP/CTSM/wiki/System-Testing-Guide#pre-merge-system-testing):
+
+    derecho ----- OK
+    izumi ------- OK
+
+Answer changes
+--------------
+
+Changes answers relative to baseline: No
+ but field lists differ due to new history field LEAFCN_TARGET
+
+Other details
+-------------
+Pull Requests that document the changes (include PR ids):
+ https://github.com/ESCOMP/ctsm/pull/1654
+
+===============================================================
+===============================================================
 Tag name: ctsm5.3.043
 Originator(s): slevis (Samuel Levis,UCAR/TSS,303-665-1310)
 Date: Fri 09 May 2025 12:28:17 PM MDT

diff --git a/doc/ChangeSum b/doc/ChangeSum
@@ -1,5 +1,6 @@
 Tag                   Who      Date  Summary
 ============================================================================================================================
+       ctsm5.3.044   slevis 05/14/2025 Introduce time-evolving LEAFCN_TARGET as function of leafcn param
        ctsm5.3.043   slevis 05/09/2025 Merge b4b-dev
        ctsm5.3.042 glemieux 05/08/2025 Update FATES tag, tests and address namelist option bug
        ctsm5.3.041 samrabin 04/25/2025 Merge b4b-dev to master

diff --git a/src/biogeochem/CNAllocationMod.F90 b/src/biogeochem/CNAllocationMod.F90
@@ -23,6 +23,7 @@ module CNAllocationMod
   use CNVegCarbonStateType , only : cnveg_carbonstate_type
   use CNVegCarbonFluxType  , only : cnveg_carbonflux_type
   use CNVegStateType       , only : cnveg_state_type
+  use CNVegNitrogenStateType, only: cnveg_nitrogenstate_type
   use CropReprPoolsMod     , only : nrepr
   use CNPhenologyMod       , only : CropPhase
   use CNSharedParamsMod    , only : use_fun
@@ -433,7 +434,7 @@ end subroutine calc_crop_allocation_fractions
 
   !-----------------------------------------------------------------------
   subroutine calc_allometry(num_soilp, filter_soilp, &
-       cnveg_carbonflux_inst, cnveg_state_inst)
+       cnveg_carbonflux_inst, cnveg_state_inst, cnveg_nitrogenstate_inst)
     !
     ! !DESCRIPTION:
     ! Calculate c_allometry and n_allometry terms based on allocation fractions
@@ -442,6 +443,7 @@ subroutine calc_allometry(num_soilp, filter_soilp, &
     integer                         , intent(in)    :: num_soilp        ! number of soil patches in filter
     integer                         , intent(in)    :: filter_soilp(:)  ! filter for soil patches
     type(cnveg_carbonflux_type)     , intent(in)    :: cnveg_carbonflux_inst
+    type(cnveg_nitrogenstate_type)  , intent(in)    :: cnveg_nitrogenstate_inst
     type(cnveg_state_type)          , intent(inout) :: cnveg_state_inst
     !
     ! !LOCAL VARIABLES:
@@ -464,7 +466,7 @@ subroutine calc_allometry(num_soilp, filter_soilp, &
          croot_stem  => pftcon%croot_stem                      ,  & ! Input:  allocation parameter: new coarse root C per new stem C (gC/gC)
          stem_leaf   => pftcon%stem_leaf                       ,  & ! Input:  allocation parameter: new stem c per new leaf C (gC/gC)
          flivewd     => pftcon%flivewd                         ,  & ! Input:  allocation parameter: fraction of new wood that is live (phloem and ray parenchyma) (no units)
-         leafcn      => pftcon%leafcn                          ,  & ! Input:  leaf C:N (gC/gN)
+         leafcn_t_evolving => cnveg_nitrogenstate_inst%leafcn_t_evolving_patch,  & ! Input:  leaf C:N (gC/gN)
          frootcn     => pftcon%frootcn                         ,  & ! Input:  fine root C:N (gC/gN)
          livewdcn    => pftcon%livewdcn                        ,  & ! Input:  live wood (phloem and ray parenchyma) C:N (gC/gN)
          deadwdcn    => pftcon%deadwdcn                        ,  & ! Input:  dead wood (xylem and heartwood) C:N (gC/gN)
@@ -503,7 +505,7 @@ subroutine calc_allometry(num_soilp, filter_soilp, &
        else
           g1 = grperc(ivt(p))
        end if
-       cnl  = leafcn(ivt(p))
+       cnl  = leafcn_t_evolving(p)
        cnfr = frootcn(ivt(p))
        cnlw = livewdcn(ivt(p))
        cndw = deadwdcn(ivt(p))

diff --git a/src/biogeochem/CNDriverMod.F90 b/src/biogeochem/CNDriverMod.F90
@@ -429,7 +429,7 @@ subroutine CNDriverNoLeaching(bounds,
        end if
 
        call calc_allometry(num_bgc_vegp, filter_bgc_vegp, &
-            cnveg_carbonflux_inst, cnveg_state_inst)
+            cnveg_carbonflux_inst, cnveg_state_inst, cnveg_nitrogenstate_inst)
        call t_stopf('cnalloc')
     end if
 

diff --git a/src/biogeochem/CNFUNMod.F90 b/src/biogeochem/CNFUNMod.F90
@@ -216,7 +216,7 @@ subroutine CNFUNInit (bounds,cnveg_state_inst,cnveg_carbonstate_inst,cnveg_nitro
 
 ! Set local pointers
   associate(ivt                    => patch%itype                                          , & ! Input:  [integer  (:)   ]  p
-         leafcn                 => pftcon%leafcn                                        , & ! Input:  leaf C:N (gC/gN)
+         leafcn_t_evolving      => cnveg_nitrogenstate_inst%leafcn_t_evolving_patch     , & ! Input:  leaf C:N (gC/gN)
          leafcn_offset          => cnveg_state_inst%leafcn_offset_patch                 , & ! Output:
          !  [real(r8) (:)   ]  Leaf C:N used by FUN  
          leafc_storage_xfer_acc => cnveg_carbonstate_inst%leafc_storage_xfer_acc_patch  , & ! Output: [real(r8) (:)
@@ -249,7 +249,7 @@ subroutine CNFUNInit (bounds,cnveg_state_inst,cnveg_carbonstate_inst,cnveg_nitro
   !---
   numofyear = nstep/nstep_fun
   if (mod(nstep,nstep_fun) == 0) then
-     leafcn_offset(bounds%begp:bounds%endp)          = leafcn(ivt(bounds%begp:bounds%endp))
+     leafcn_offset(bounds%begp:bounds%endp)          = leafcn_t_evolving(bounds%begp:bounds%endp)
      storage_cdemand(bounds%begp:bounds%endp)        = 0._r8
      storage_ndemand(bounds%begp:bounds%endp)        = 0._r8
      leafn_storage_xfer_acc(bounds%begp:bounds%endp) = 0._r8
@@ -573,7 +573,7 @@ subroutine CNFUN(bounds,num_soilc, filter_soilc,num_soilp&
   !--------------------------------------------------------------------
   !---------------------------------
   associate(ivt                 => patch%itype                                          , & ! Input:   [integer  (:) ]  p
-         leafcn                 => pftcon%leafcn                                        , & ! Input:   leaf C:N (gC/gN)
+         leafcn_t_evolving      => cnveg_nitrogenstate_inst%leafcn_t_evolving_patch     , & ! Input:   leaf C:N (gC/gN)
          season_decid           => pftcon%season_decid                                  , & ! Input:   binary flag for seasonal
          ! -deciduous leaf habit (0 or 1)
          stress_decid           => pftcon%stress_decid                                  , & ! Input:   binary flag for stress
@@ -1276,7 +1276,7 @@ subroutine CNFUN(bounds,num_soilc, filter_soilc,num_soilp&
                                 litterfall_c_step(p,istp)* fixerfrac,&
                                 litterfall_n_step(p,istp)* fixerfrac,&
                                 total_n_resistance, total_c_spent_retrans,total_c_accounted_retrans, &
-                                free_n_retrans,paid_for_n_retrans, leafcn(ivt(p)), & 
+                                free_n_retrans,paid_for_n_retrans, leafcn_t_evolving(p), &
                                 grperc(ivt(p)), plantCN(p))
 
                else
@@ -1307,7 +1307,7 @@ subroutine CNFUN(bounds,num_soilc, filter_soilc,num_soilp&
                      if (leafn(p) == 0.0_r8) then   ! to avoid division by zero
                        delta_CN = fun_cn_flex_c(ivt(p))   ! Max CN ratio over standard
                      else
-                       delta_CN = (leafc(p)+leafc_storage(p))/(leafn(p)+leafn_storage(p)) - leafcn(ivt(p)) ! leaf CN ratio                                                              
+                       delta_CN = (leafc(p)+leafc_storage(p))/(leafn(p)+leafn_storage(p)) - leafcn_t_evolving(p) ! leaf CN ratio
                      end if
                      ! C used for uptake is reduced if the cost of N is very high
                      frac_ideal_C_use = max(0.0_r8,1.0_r8 - (total_N_resistance-fun_cn_flex_a(ivt(p)))/fun_cn_flex_b(ivt(p)) )

diff --git a/src/biogeochem/CNGRespMod.F90 b/src/biogeochem/CNGRespMod.F90
@@ -60,7 +60,6 @@ subroutine CNGResp(num_soilp, filter_soilp, cnveg_carbonflux_inst, canopystate_i
          woody                         =>    pftcon%woody                                              , & ! Input:  binary flag for woody lifeform (1=woody, 0=not woody)
          grperc                        =>    pftcon%grperc                                             , & ! Input:  growth respiration parameter
          grpnow                        =>    pftcon%grpnow                                             , & ! Input:  growth respiration parameter
-         leafcn                        =>    pftcon%leafcn                                             , & ! Input:  leaf C:N (gC/gN)                         
          livewdcn                      =>    pftcon%livewdcn                                           , & ! Input:  live wood (phloem and ray parenchyma) C:N (gC/gN)  
 
          laisun                        =>    canopystate_inst%laisun_patch                             , & ! Input:  [real(r8) (:)]  sunlit projected leaf area index      

diff --git a/src/biogeochem/CNGapMortalityMod.F90 b/src/biogeochem/CNGapMortalityMod.F90
@@ -163,7 +163,6 @@ subroutine CNGapMortality (bounds, num_soilp, filter_soilp, &
          greffic                  => dgvs_inst%greffic_patch    , & ! Input:  [real(r8) (:) ]                                                    
          heatstress               => dgvs_inst%heatstress_patch , & ! Input:  [real(r8) (:) ]    
 
-         leafcn                   => pftcon%leafcn               , & ! Input:  [real(r8) (:)]  leaf C:N (gC/gN)                        
          livewdcn                 => pftcon%livewdcn             , & ! Input:  [real(r8) (:)]  live wood (phloem and ray parenchyma) C:N (gC/gN) 
          laisun                   => canopystate_inst%laisun_patch  , & ! Input:  [real(r8) (:)   ]  sunlit projected leaf area index      
          laisha                   => canopystate_inst%laisha_patch  , & ! Input:  [real(r8) (:)   ]  shaded projected leaf area index
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		paramfile = '$DIN_LOC_ROOT/lnd/clm2/paramdata/ctsm60_ceta450_cn30_co2_slope30.c250326.nc'