Merge pull request #354 from ckoven/decouple_trim_from_broot

Optional decoupling of fine root biomass from canopy trim logic

Author: rgknox

biogeochem/EDPhysiologyMod.F90

@@ -193,9 +193,12 @@ subroutine trim_canopy( currentSite )
           endif
 
           call bleaf(currentcohort%dbh,ipft,currentcohort%canopy_trim,tar_bl)
-          call bfineroot(currentcohort%dbh,ipft,currentcohort%canopy_trim,tar_bfr)
 
-          bfr_per_bleaf = tar_bfr/tar_bl
+          if ( int(EDPftvarcon_inst%allom_fmode(ipft)) .eq. 1 ) then
+             ! only query fine root biomass if using a fine root allometric model that takes leaf trim into account
+             call bfineroot(currentcohort%dbh,ipft,currentcohort%canopy_trim,tar_bfr)
+             bfr_per_bleaf = tar_bfr/tar_bl
+          endif
 
           !Leaf cost vs netuptake for each leaf layer. 
           do z = 1,nlevleaf
@@ -207,18 +210,27 @@ subroutine trim_canopy( currentSite )
 
 
                    currentCohort%leaf_cost =  1._r8/(EDPftvarcon_inst%slatop(ipft)*1000.0_r8)
-                   currentCohort%leaf_cost = currentCohort%leaf_cost + &
-                        1.0_r8/(EDPftvarcon_inst%slatop(ipft)*1000.0_r8) * &
-                        bfr_per_bleaf / EDPftvarcon_inst%root_long(ipft)
+
+                   if ( int(EDPftvarcon_inst%allom_fmode(ipft)) .eq. 1 ) then
+                      ! if using trimmed leaf for fine root biomass allometry, add the cost of the root increment
+                      ! to the leaf increment; otherwise do not.
+                      currentCohort%leaf_cost = currentCohort%leaf_cost + &
+                           1.0_r8/(EDPftvarcon_inst%slatop(ipft)*1000.0_r8) * &
+                           bfr_per_bleaf / EDPftvarcon_inst%root_long(ipft)
+                   endif
 
                    currentCohort%leaf_cost = currentCohort%leaf_cost * &
                          (EDPftvarcon_inst%grperc(ipft) + 1._r8)
                 else !evergreen costs
                    currentCohort%leaf_cost = 1.0_r8/(EDPftvarcon_inst%slatop(ipft)* &
                         EDPftvarcon_inst%leaf_long(ipft)*1000.0_r8) !convert from sla in m2g-1 to m2kg-1
-                   currentCohort%leaf_cost = currentCohort%leaf_cost + &
-                        1.0_r8/(EDPftvarcon_inst%slatop(ipft)*1000.0_r8) * &
-                        bfr_per_bleaf / EDPftvarcon_inst%root_long(ipft)
+                   if ( int(EDPftvarcon_inst%allom_fmode(ipft)) .eq. 1 ) then
+                      ! if using trimmed leaf for fine root biomass allometry, add the cost of the root increment
+                      ! to the leaf increment; otherwise do not.
+                      currentCohort%leaf_cost = currentCohort%leaf_cost + &
+                           1.0_r8/(EDPftvarcon_inst%slatop(ipft)*1000.0_r8) * &
+                           bfr_per_bleaf / EDPftvarcon_inst%root_long(ipft)
+                   endif
                    currentCohort%leaf_cost = currentCohort%leaf_cost * &
                          (EDPftvarcon_inst%grperc(ipft) + 1._r8)
                 endif

biogeochem/FatesAllometryMod.F90

@@ -107,11 +107,9 @@ module FatesAllometryMod
   public :: StructureResetOfDH ! Method to set DBH to sync with structure biomass
   public :: CheckIntegratedAllometries
 
-
   logical         , parameter :: verbose_logging = .false.
   character(len=*), parameter :: sourcefile = __FILE__
 
-
   ! If testing b4b with older versions, do not remove sapwood
   ! Our old methods with saldarriaga did not remove sapwood from the
   ! bdead pool.  But newer allometries are providing total agb
@@ -621,14 +619,23 @@ subroutine bfineroot(d,ipft,canopy_trim,bfr,dbfrdd)
     real(r8) :: slascaler
 
     select case(int(EDPftvarcon_inst%allom_fmode(ipft)))
-    case(1) ! "constant proportionality with bleaf"
+    case(1) ! "constant proportionality with TRIMMED target bleaf"
 
        call blmax_allom(d,ipft,blmax,dblmaxdd)
        call bfrmax_const(d,blmax,dblmaxdd,ipft,bfrmax,dbfrmaxdd)
        bfr    = bfrmax * canopy_trim
        if(present(dbfrdd))then
           dbfrdd = dbfrmaxdd * canopy_trim
        end if
+    case(2) ! "constant proportionality with UNTRIMMED target bleaf"
+       
+       call blmax_allom(d,ipft,blmax,dblmaxdd)
+       call bfrmax_const(d,blmax,dblmaxdd,ipft,bfrmax,dbfrmaxdd)
+       bfr    = bfrmax
+       if(present(dbfrdd))then
+          dbfrdd = dbfrmaxdd
+       end if
+
     case DEFAULT 
        write(fates_log(),*) 'An undefined fine root allometry was specified: ', &
             EDPftvarcon_inst%allom_fmode(ipft)