problem for grass growing in dynamic mortality mode

[nicolasviovy]

with LPJ_CONST_MORTALITY false the grass cannot grow from scratch.
It comes from lpj_gap because mortality is set to 1 when npp_longterm is less than 10 which is obviously the case at the beginning of simulation. Then herb are killed and reintroduced at each stomate time step but then cannot growth.
For me it as no sense as in static mode, if condition are not favorable the vegetation is autmonatically killed by emptying the biomass when npp_longterm is null !! So I think that we should remove
the following lines:

!! 2. Grasses mortality

! For grasses, if last year's NPP is very small (less than 10 gCm^{{-2}year{-1})
! the grasses completely die
IF ( .NOT.control%ok_dgvm .AND. .NOT.lpj_gap_const_mort) THEN}

WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LE. npp_longterm_init ) )

mortality(:,j) = un

ENDWHERE

! Update biomass and litter pools
DO k = 1, nparts

WHERE ( PFTpresent(:,j) )

dmortality(:) = mortality(:,j) * biomass(:,j,k)

bm_to_litter(:,j,k) = bm_to_litter(:,j,k) + dmortality(:)

biomass(:,j,k) = biomass(:,j,k) - dmortality(:)

ENDWHERE

ENDDO

ENDIF

all this as been added when we merged the corrections of Sönke of the DGVM done in OCN with ORCHIDEE... But likewise I am not convinced at all by the way the static mode is treated in lpj_establish with dynamic mortality because, like in DGVM mode, new individuals are created each time (where cover is not closed) and then new biomass from sapling is added (i.e CO2_TAKEN is not null) what as no sense for me. So I would like to have you advice (in particular from Nicolas and Sebastiaan) about that ?

[jgipsl]

As decided during the ORCHIDEE Day 8 Sept 2017, a stop in the model has been added for the case ok_dgvm=F and LPJ_GAP_CONST_MORT=F. Done in the trunk rev [4622]

Change milestone for the ticket.

[nicolasviovy]

see last comment, this problem is no more relevant so ticket is closed