Changes between Version 142 and Version 143 of DevelopmentActivities/ORCHIDEE-DOFOCO

Timestamp:

2017-06-22T16:14:40+02:00 (8 years ago)

Author:

luyssaert

Comment:

--

DevelopmentActivities/ORCHIDEE-DOFOCO

@@ -164 +164 @@
 
 === Litter raking ===
-USE_LITTER_RAKING=n
+Tree litter was collected from the forest and used in the winter stables instead of straw. In spring the litter and manure was spread on the croplands. This lateral flow of C and N between PFTS in the same pixel can be accounted for in ORCHIDEE-CN-CAN by setting '''use_litter_raking''' = y. If litter raking is to be used, the model will search for annual maps. The path of these maps needs to be specified in COMP/stomate.card. Litter raking maps were prepared for Europe. Unless liter raking is your research topic set '''use_litter_raking''' = n.
+
+=== Mortality ===
+ORCHIDEE-CN-CAN distinguished 3 types of natural mortality. The first two options are similar to those in previous version of ORCHIDEE and are set by the flag '''constant_mortality'''. If '''constant_mortality''' = y, the background mortality of a forests is calculated as a constant, prescribed fraction. In ORCHIDEE-CN-CAN, this fraction is given by '''residence_time''' (see also forest management). . If '''constant_mortality''' = y, the background mortality of a forest is a function of its net primary production (npp). If npp decreases, mortality will increase. 
+
+Both options have been developed, tested and can be used in ORCHIDEE-CN-CAN. However, because of the introduction of self-thinning mortality in ORCHIDEE-CN-CAN, '''constant_mortality''' = y soon became the default setting. In ORCHIDEE-CN-CAN, the total mortality is the maximum of the background mortality and the mortality from self-thinning. Only if self-thinning is absent or too low, background mortality will play a role. This approach implies that when '''constant_mortality''' = y is used in combination with self-thinning, background mortality will only play a role in the first years to decade before self-thinning starts. Despite its limited use, it represents an essential process: owing to background mortality, the number of individuals decreases, the remaining individuals grow faster and thus manage to reach self-thinning in a reasonable amount of time. It needs to be tested how the interplay between background mortality and self-thinning will work out when '''constant_mortality''' = n is used.
 
 === Nitrogen cycle ===
@@ -253 +258 @@
 Similar to ORCHIDEE-CN, ORCHIDEE-CN-CAN users can choose to use a constant specific leaf area (SLA) or a dynamic (SLA) by setting the flag '''dyn_sla'''. SLA is a fundamental parameter in the allocation scheme and it is well established that SLA is dynamic in nature especially during leaf onset. The current implementation of dynamic SLA is basic and there is room to enhance consistency in the calculations, for example, by recalculation the allocation factors KF and LF as a function of SLA.
 
-=== stomate ===
+=== Stomate ===
 ORCHIDEE-CN-CAN strengthen the links between sechiba and stomate. As in previous versions, stomate makes use of variables calculated in sechiba but in ORCHIDEE-CAN and ORCHIDEE-CN-CAN, sechiba requires information from stomate to work properly. For the moment set '''stomate_ok_stomate''' to y (_AUTOBLOCKER_). For the future it seems possible to prescribe LAI and assume a canopy structure but this code still needs to be restored and tested. For the time being set '''lai_map''' = n.