Index: LMDZ5/trunk/libf/phylmd/clesphys.h
===================================================================
--- LMDZ5/trunk/libf/phylmd/clesphys.h	(revision 2972)
+++ LMDZ5/trunk/libf/phylmd/clesphys.h	(revision 2973)
@@ -91,4 +91,6 @@
        LOGICAL :: adjust_tropopause
        LOGICAL :: ok_daily_climoz
+! flag to bypass or not the phytrac module
+       INTEGER :: iflag_phytrac
 
        COMMON/clesphys/                                                 &
@@ -137,5 +139,6 @@
      &     , iflag_ice_thermo, ok_gwd_rando, NSW, iflag_albedo          &
      &     , ok_chlorophyll,ok_conserv_q, adjust_tropopause             &
-     &     , ok_daily_climoz, ok_all_xml
+     &     , ok_daily_climoz, ok_all_xml                                &
+     &     , iflag_phytrac
      
        save /clesphys/
Index: LMDZ5/trunk/libf/phylmd/phys_output_write_mod.F90
===================================================================
--- LMDZ5/trunk/libf/phylmd/phys_output_write_mod.F90	(revision 2972)
+++ LMDZ5/trunk/libf/phylmd/phys_output_write_mod.F90	(revision 2973)
@@ -1906,4 +1906,5 @@
 #endif
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+       IF (iflag_phytrac == 1 ) then
        IF (nqtot.GE.nqo+1) THEN
           DO iq=nqo+1, nqtot
@@ -1936,4 +1937,6 @@
           ENDDO
        ENDIF
+       ENDIF   !(iflag_phytrac==1)
+
 
        IF (.NOT.vars_defined) THEN
Index: LMDZ5/trunk/libf/phylmd/physiq_mod.F90
===================================================================
--- LMDZ5/trunk/libf/phylmd/physiq_mod.F90	(revision 2972)
+++ LMDZ5/trunk/libf/phylmd/physiq_mod.F90	(revision 2973)
@@ -1237,4 +1237,6 @@
        fl_cor_ebil = 0 ! by default, no correction to ensure energy conservation
        CALL getin_p('fl_cor_ebil',fl_cor_ebil)
+       iflag_phytrac = 0 ! by default we do not want to call phytrac
+       CALL getin_p('iflag_phytrac',iflag_phytrac)
     ENDIF
 
@@ -4258,4 +4260,6 @@
     ENDIF
 
+    IF (iflag_phytrac == 1 ) THEN
+
 #ifdef CPP_Dust
       CALL       phytracr_spl ( debut,lafin , jD_cur,jH_cur,iflag_con,       &  ! I
@@ -4301,4 +4305,5 @@
          tr_seri)
 #endif
+    ENDIF    ! (iflag_phytrac=1)
 
     IF (offline) THEN