Changes between Version 28 and Version 29 of Documentation/TrunkFunctionality4

Timestamp:

2020-03-27T14:20:06+01:00 (4 years ago)

Author:

luyssaert

Comment:

--

Documentation/TrunkFunctionality4

@@ -235 +235 @@
 ORCHIDEE trunk 4 calculates the number of individuals and uses this as a criterion to initiate a stand replacing disturbance. This approach, guided by the self-thinning relationship, avoids the need for a stand-level turnover time. ORCHIDEE-CN, and ORCHIDEE-CNP still make use of stand-level turnover. Note that the meaning of residence_time is very different between the CAN branch and the trunk.  In the trunk biomass has no age and thus the residence time accounts for all forest dynamics including self-thinning, pests, diseases and windthrow. In the CAN branch, biomass does have an age and self-thinning is explicitly accounted for, hence, the residence time should be much higher as it only accounts for pest, diseases and windthrow. Even the latter is not exact because as long as those disturbances are small scale they are probably accounted for in the parametrization of self-thinning.
 
-=== Nitrogen cycle (CHECK) ===
+=== Nitrogen cycle (r6614) ===
 ORCHIDEE trunk 4 strictly follows ORCHIDEE trunk 3 where it concerns the implementation of the N-cycle. Following mass balance problems caused by negative N mineralization and followed by negative immobilization, the code has been slightly adjusted to ensure mass balance closure. First the flag '''stomate_ok_ncycle''' needs to be set to y, to run the model with a N-cycle. Subsequently the parameter '''impose_cn''' is used to control the N-cycle calculations. If set to y, C/N ratios are calculated but whenever N appears to be limiting, it is taken from the atmosphere to satisfy this need. This is the preferred setting when testing/developing the code without a proper spin-up. N-limitation will only be accounted for when setting impose_cn = n. With this setting the N-cycle is closed (checked when checking for mass balance closure) it requires a spin-up to produce reasonable results.