Context Navigation

lpj_gap.f90 @ 6737

Last change on this file since 6737 was 4507, checked in by albert.jornet, 7 years ago
Merge: from revisions [4467:4491/trunk/ORCHIDEE]
Property svn:keywords set to `HeadURL Date Author Revision`
File size: 15.2 KB

Line
1	! =================================================================================================================================
2	! MODULE : lpj_gap
3	!
4	! CONTACT : orchidee-help _at_ listes.ipsl.fr
5	!
6	! LICENCE : IPSL (2006)
7	! This software is governed by the CeCILL licence see ORCHIDEE/ORCHIDEE_CeCILL.LIC
8	!
9	!>\BRIEF Simulate mortality of individuals and update biomass, litter and
10	!! stand density of the PFT
11	!!
12	!!\n DESCRIPTION : Simulate mortality of individuals and update biomass, litter and
13	!! stand density of the PFT. This module differs from lpj_kill.f90 in that this
14	!! module kills individuals within a PFT and lpj_kill.f90 removes a PFT from a
15	!! gridbox
16	!!
17	!! RECENT CHANGE(S): None
18	!!
19	!! REFERENCE(S) :
20	!! - Sitch, S., B. Smith, et al. (2003), Evaluation of ecosystem dynamics,
21	!! plant geography and terrestrial carbon cycling in the LPJ dynamic
22	!! global vegetation model, Global Change Biology, 9, 161-185.\n
23	!! - Waring, R. H. (1983). "Estimating forest growth and efficiency in relation
24	!! to canopy leaf area." Advances in Ecological Research 13: 327-354.\n
25	!!
26	!! SVN :
27	!! $HeadURL$
28	!! $Date$
29	!! $Revision$
30	!! \n
31	!_ ================================================================================================================================
32
33	MODULE lpj_gap
34
35	! modules used:
36	USE xios_orchidee
37	USE stomate_data
38	USE pft_parameters
39	USE ioipsl_para
40	USE constantes
41
42	IMPLICIT NONE
43
44	! private & public routines
45
46	PRIVATE
47	PUBLIC gap,gap_clear
48
49	! Variable declaration
50
51	LOGICAL, SAVE :: firstcall_gap = .TRUE. !! first call flag
52	!$OMP THREADPRIVATE(firstcall_gap)
53	REAL(r_std), PARAMETER :: frost_damage_limit = -3 + ZeroCelsius !! Spring frost-damage limitation (K)
54	REAL(r_std), PARAMETER :: coldness_mort = 0.04 !! Daily mortality induced by extreme coldness in winter
55	CONTAINS
56
57
58	!! ================================================================================================================================
59	!! SUBROUTINE : gap_clear
60	!!
61	!>\BRIEF Set the firstcall_gap flag back to .TRUE. to prepare for the next simulation.
62	!_ ================================================================================================================================
63
64	SUBROUTINE gap_clear
65	firstcall_gap = .TRUE.
66	END SUBROUTINE gap_clear
67
68
69	!! ================================================================================================================================
70	!! SUBROUTINE : gap
71	!!
72	!>\BRIEF Simulate tree and grass mortality, transfer dead biomass to litter and update stand density
73	!!
74	!! DESCRIPTION : Calculate mortality of trees and grasses, transfer the dead biomass to litter pool,
75	!! and update biomass pool and number of individuals. To get tree mortality, it's possible to choose either a
76	!! constant mortality rate; or to calculate the tree mortality rate based on it's growth efficiency, which is
77	!! defined as this year's net biomass increment per leaf area.\n
78	!!
79	!! When using growth efficiency mortality, first calculate the net biomass increment for the last year, then
80	!! calculate the growth efficiency and finally calculate the growth efficiency mortality.\n
81	!!
82	!! Eqation to calculate growth efficiency:
83	!! \latexonly
84	!! \input{gap1.tex}
85	!! \endlatexonly
86	!! Where $greff$ is growth efficiency, $\Delta$ is net biomass increment,
87	!! $C_{leaf} is last year's leaf biomass, and $SLA$ the specific leaf area.
88	!!
89	!!
90	!! Eqation to calculate growth efficiency mortality:
91	!! \latexonly
92	!! \input{gap2.tex}
93	!! \endlatexonly
94	!! Where $mort_{greff}$ is the growth efficiency mortality, $greff$ is growth
95	!! efficiency, $k_{mort1}$ is asymptotic maximum mortality rate.
96	!!
97	!! The name for variable ::availability is not well chosen. Actually the meaning of the variable is mortailty
98	!! rate derived from growth efficiency related mortality. ?? Suggestion: change the name "availability" to
99	!! "mortgref", which means "mortality caused by ".\n
100	!!
101	!! RECENT CHANGE(S): None
102	!!
103	!! MAIN OUTPUT VARIABLE(S): ::biomass; biomass, ::ind density of individuals, ::bm_to_litter biomass transfer
104	!! to litter and ::mortality mortality (fraction of trees that is dying per time step)
105	!!
106	!! REFERENCE(S) :
107	!! - Sitch, S., B. Smith, et al. (2003), Evaluation of ecosystem dynamics,
108	!! plant geography and terrestrial carbon cycling in the LPJ dynamic
109	!! global vegetation model, Global Change Biology, 9, 161-185.
110	!! - Waring, R. H. (1983). "Estimating forest growth and efficiency in relation
111	!! to canopy leaf area." Advances in Ecological Research 13: 327-354.
112	!!
113	!! FLOWCHART : None
114	!!\n
115	!_ ================================================================================================================================
116
117	SUBROUTINE gap (npts, dt, &
118	npp_longterm, turnover_longterm, lm_lastyearmax, &
119	PFTpresent, biomass, ind, bm_to_litter, mortality, t2m_min_daily, Tmin_spring_time, &
120	sla_calc)
121
122
123	!! 0. Variable and parameter declaration
124
125	!! 0.1 Input variables
126	INTEGER(i_std), INTENT(in) :: npts !! Domain size (-)
127	REAL(r_std), INTENT(in) :: dt !! Time step (days)
128	REAL(r_std), DIMENSION(npts,nvm), INTENT(in) :: npp_longterm !! "Long term" (default 3-year) net primary
129	!! productivity
130	!! @tex $(gC m^{-2} year^{-1})$ @endtex
131	REAL(r_std), DIMENSION(npts,nvm,nparts,nelements), INTENT(in) :: turnover_longterm !! "Long term" (default 3-year) turnover
132	!! rate @tex $(gC m^{-2} year^{-1})$ @endtex
133	REAL(r_std), DIMENSION(npts,nvm), INTENT(in) :: lm_lastyearmax !! Last year's maximum leaf mass, for each
134	!! PFT @tex $(gC m^{-2})$ @endtex
135	LOGICAL, DIMENSION(npts,nvm), INTENT(in) :: PFTpresent !! Is the pft present in the pixel
136	REAL(r_std), DIMENSION(npts), INTENT(in) :: t2m_min_daily !! Daily minimum 2 meter temperatures (K)
137	REAL(r_std), DIMENSION(npts,nvm), INTENT(in) :: Tmin_spring_time !! Number of days after begin_leaves (leaf onset)
138
139	!! 0.2 Output variables
140
141	REAL(r_std), DIMENSION(npts,nvm),INTENT(out) :: mortality !! Mortality (fraction of trees that is
142	!! dying per time step)
143
144	!! 0.3 Modified variables
145
146	REAL(r_std), DIMENSION(npts,nvm,nparts,nelements), INTENT(inout) :: biomass !! Biomass @tex $(gC m^{-2}) $@endtex
147	REAL(r_std), DIMENSION(npts,nvm), INTENT(inout) :: ind !! Number of individuals
148	!! @tex $(m^{-2})$ @endtex
149	REAL(r_std), DIMENSION(npts,nvm,nparts,nelements), INTENT(inout) :: bm_to_litter !! Biomass transfer to litter
150	!! @tex $(gC m^{-2})$ @endtex
151	!gmjc
152	REAL(r_std), DIMENSION(npts,nvm), INTENT(in) :: sla_calc
153	!end gmjc
154	!! 0.4 Local variables
155
156	REAL(r_std), DIMENSION(npts) :: delta_biomass !! Net biomass increase for the previous
157	!! year @tex $(gC m^{-2} year^{-1})$ @endtex
158	REAL(r_std), DIMENSION(npts) :: dmortality !! Dead biomass caused by mortality
159	!! @tex $(gC m^{-2}) $@endtex
160	REAL(r_std), DIMENSION(npts) :: vigour !! Growth efficiency, an indicator of tree
161	!! vitality, used to calculate mortality
162	REAL(r_std), DIMENSION(npts) :: availability !! Mortality rate derived by growth
163	!! efficiency @tex $(year^{-1})$ @endtex
164	INTEGER(i_std) :: i, j,k,m !! Indices
165
166	!_ ================================================================================================================================
167
168	IF ( firstcall_gap ) THEN
169
170	firstcall_gap = .FALSE.
171
172	ENDIF
173
174	IF (printlev>=3) WRITE(numout,*) 'Entering gap',lpj_gap_const_mort
175
176	mortality(:,:) = zero
177
178	! loop over #PFT
179	DO j = 2,nvm
180
181	IF (natural(j)) THEN
182	!! 1. Tree mortality
183
184	IF ( is_tree(j) ) THEN
185
186	!! 1.1 Use growth efficiency or constant mortality?
187	IF ( .NOT. lpj_gap_const_mort ) THEN
188
189	!! 1.1.1 Estimate net biomass increment
190	! To calculate growth efficiency mortality, first estimate net biomass increment by
191	! subtracting turnover from last year's NPP.
192	WHERE ( PFTpresent(:,j) .AND. ( lm_lastyearmax(:,j) .GT. min_stomate ) )
193
194	!??! the following should be removed
195	! note that npp_longterm is now actually longterm growth efficiency (NPP/LAI)
196	! to be fair to deciduous trees
197	! calculate net biomass increment
198	delta_biomass(:) = MAX( npp_longterm(:,j) - ( turnover_longterm(:,j,ileaf,icarbon) + &
199	turnover_longterm(:,j,iroot,icarbon) + turnover_longterm(:,j,ifruit,icarbon) + &
200	turnover_longterm(:,j,isapabove,icarbon) + turnover_longterm(:,j,isapbelow,icarbon) ) ,zero)
201
202	!! 1.1.2 Calculate growth efficiency
203	! Calculate growth efficiency by dividing net biomass increment by last year's
204	! maximum LAI. (corresponding actually to the maximum LAI of the previous year)
205	!JCMODIF
206	! vigour(:) = delta_biomass(:) / (lm_lastyearmax(:,j)*sla(j))
207	vigour(:) = delta_biomass(:) / (lm_lastyearmax(:,j)*sla_calc(:,j))
208	!ENDJCMODIF
209
210	ELSEWHERE
211
212	vigour(:) = zero
213
214	ENDWHERE
215
216	!! 1.1.3 Calculate growth efficiency mortality rate
217	WHERE ( PFTpresent(:,j) )
218
219	availability(:) = availability_fact(j) / ( un + ref_greff * vigour(:) )
220	! Scale mortality by timesteps per year
221	mortality(:,j) = MAX(min_avail,availability(:)) * dt/one_year
222
223	ENDWHERE
224
225	ELSE ! .NOT. lpj_gap_const_mort
226
227	!! 1.2 Use constant mortality accounting for the residence time of each tree PFT
228	WHERE ( PFTpresent(:,j) )
229
230	mortality(:,j) = dt/(residence_time(j)*one_year)
231
232	ENDWHERE
233
234	ENDIF ! .NOT. lpj_gap_const_mort
235
236	!! 1.3 Mortality in DGVM
237	! If the long term NPP is zero, all trees are killed
238	!??! This is this only applied in the DGVM maybe in order to make the DGVM respond faster and thus make the vegetation dynamics more dynamic?
239	!??! the link here with lpj_kill.f90 is still not clear and so would leave to who especially working on this.
240	IF ( ok_dgvm ) THEN
241
242	! WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LE. min_stomate ) )
243	WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LT. (npp_longterm_init-un) ) )
244	mortality(:,j) = un
245
246	ENDWHERE
247
248	ENDIF
249
250	IF ( ok_dgvm .AND. (tmin_crit(j) .NE. undef) ) THEN
251	! frost-sensitive PFTs
252	WHERE ( t2m_min_daily(:) .LT. tmin_crit(j) )
253	mortality(:,j) = MIN(un,(coldness_mort*(tmin_crit(j)-t2m_min_daily(:))+mortality(:,j) ) )
254	ENDWHERE
255	ENDIF
256
257	IF ( ok_dgvm .AND. leaf_tab(j)==1 .AND. pheno_type(j)==2) THEN
258	! Treat the spring frost for broadleaf and summergreen vegetations
259	! leaf_tab=broadleaf and pheno_typ=summergreen
260	DO i=1,npts
261	IF ( (Tmin_spring_time(i,j)>0) .AND. (Tmin_spring_time(i,j)<spring_days_max+1) ) THEN
262	IF ( t2m_min_daily(i) .LT. frost_damage_limit ) THEN
263	mortality(i,j) = MIN(un,(0.01(frost_damage_limit-t2m_min_daily(i)) &
264	Tmin_spring_time(i,j)/spring_days_max+mortality(i,j) ) )
265	END IF
266	END IF
267	END DO
268	ENDIF
269
270	!! 1.4 Update biomass and litter pools
271	! Update biomass and litter pool after dying and transfer recently died biomass to litter
272
273	DO m = 1,nelements
274	DO k = 1, nparts
275
276	WHERE ( PFTpresent(:,j) )
277
278	dmortality(:) = mortality(:,j) * biomass(:,j,k,m)
279	bm_to_litter(:,j,k,m) = bm_to_litter(:,j,k,m) + dmortality(:)
280	biomass(:,j,k,m) = biomass(:,j,k,m) - dmortality(:)
281
282	ENDWHERE
283
284	ENDDO
285	END DO
286
287	!! 1.5 In case of dynamic vegetation, update tree individual density
288	IF ( ok_dgvm ) THEN
289
290	WHERE ( PFTpresent(:,j) )
291
292	ind(:,j) = ind(:,j) * ( un - mortality(:,j) )
293
294	ENDWHERE
295
296	ENDIF
297	ELSE
298
299	!! 2. Grasses mortality
300
301	! For grasses, if last year's NPP is very small (less than 10 gCm^{-2}year{-1})
302	! the grasses completely die
303	! IF ( .NOT.ok_dgvm .AND. .NOT.lpj_gap_const_mort) THEN
304	! JC comment: though natural(j) is defined before do we still need pasture here?
305	! IF ( ok_dgvm ) THEN
306	IF ( ok_dgvm .AND. natural(j) .AND. .NOT. pasture(j)) THEN
307
308	! WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LE. min_stomate ) ) !npp_longterm_init ) )
309	WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LT. (npp_longterm_init-un) ) )
310	mortality(:,j) = un
311
312	ENDWHERE
313
314	ENDIF
315
316	! Update biomass and litter pools
317	DO m = 1,nelements
318	DO k = 1, nparts
319
320	WHERE ( PFTpresent(:,j) )
321
322	dmortality(:) = mortality(:,j) * biomass(:,j,k,m)
323
324	bm_to_litter(:,j,k,m) = bm_to_litter(:,j,k,m) + dmortality(:)
325
326	biomass(:,j,k,m) = biomass(:,j,k,m) - dmortality(:)
327
328	ENDWHERE
329
330	ENDDO
331	ENDDO
332
333	IF ( ok_dgvm ) THEN
334
335	WHERE ( PFTpresent(:,j) )
336
337	ind(:,j) = ind(:,j) * ( un - mortality(:,j) )
338
339	ENDWHERE
340
341	ENDIF
342
343	ENDIF !IF ( is_tree(j) )
344
345	ENDIF ! IF(natural(j))
346	ENDDO !loop over pfts
347
348	!! 3. Write to history files
349
350	! output in fraction of trees that dies/day.
351	mortality(:,:) = mortality(:,:) / dt
352
353	CALL xios_orchidee_send_field("mortality",mortality)
354
355	CALL histwrite_p (hist_id_stomate, 'MORTALITY', itime, &
356	mortality, npts*nvm, horipft_index)
357
358	IF (printlev>=4) WRITE(numout,*) 'Leaving gap'
359
360	END SUBROUTINE gap
361
362	END MODULE lpj_gap

Note: See TracBrowser for help on using the repository browser.

Context Navigation

source: branches/publications/ORCHIDEE_GLUC_r6545/src_stomate/lpj_gap.f90 @ 6737

Download in other formats: