Add tolerance to disturbance check to resolve issue with precision er…

…ror.

biogeochem/EDPatchDynamicsMod.F90

@@ -481,6 +481,8 @@ subroutine spawn_patches( currentSite, bc_in)
                                              ! for both woody and grass species
     real(r8) :: leaf_m                       ! leaf mass during partial burn calculations
     logical  :: found_youngest_primary       ! logical for finding the first primary forest patch
+
+    real(r8), parameter :: disturb_tolerance = 1.0e-14_r8 ! Allow for a small precision errors.
     !---------------------------------------------------------------------
 
     storesmallcohort => null() ! storage of the smallest cohort for insertion routine
@@ -500,7 +502,7 @@ subroutine spawn_patches( currentSite, bc_in)
     do while(associated(currentPatch))
 
 
-       if(currentPatch%disturbance_rate>1.0_r8) then
+       if(currentPatch%disturbance_rate > (1.0_r8 + disturb_tolerance)) then
           write(fates_log(),*) 'patch disturbance rate > 1 ?',currentPatch%disturbance_rate
           call dump_patch(currentPatch)
           call endrun(msg=errMsg(sourcefile, __LINE__))