Changes between Version 11 and Version 12 of DevelopmentActivities/ORCHIDEE-CNP/issues

Timestamp:

2016-03-22T17:27:18+01:00 (8 years ago)

Author:

dgoll

Comment:

--

DevelopmentActivities/ORCHIDEE-CNP/issues

@@ -28 +28 @@
 Thus, we should make the CNP ratio of wood fixed; this needs substantial modifications in the code. These modification are at the moment not feasible. I suggest to work on that as as soon as the model works well.
 
-=== MAJOR ISSUE: Effect of nutrient stress on root/leaf ratio ===
-The effect of long-term nitrogen stress on the ratio between roots and leaves of O-CN is commented out in the ORCHIDEE-CN.  We should reintroduce the effect of nutrient stress on that ratio. 
-This task is hampered by my difficulties to understand how water stress is affecting the ratio in DOFOCO vs ORCHIDEE-CN.
+===  Effect of nutrient stress on root/leaf ratio ===
+The effect of long-term nitrogen stress on the ratio between roots and leaves of O-CN is commented out in the ORCHIDEE-CN.  We could reintroduce the effect of nutrient stress on that ratio. 
+However, SL warns of the introducing modifiers on the allocation ratio. DOFOCO does not account for any water stress effect on root/leaf ratio (unlike described in Naudts et al. 2014). Before introducing any effects on the allocation ratios, the way forward has to be clarified and harmonized with NV and SL.
+For now this is on ice.
 
-
-=== Too much heartwood ===
-I experience that the heartwood pool is still accumulating biomass after 500 yr of simulation reaching a stock of appr. 45kg/m2. This is very high compared to estimates of total biomass ranging between 3-15 kg/m2 (Houghton et al. 2005).  When using the value for tau_sap of the trunk version of ORCHIDEE (730days) instead of ORCHIDEE-CAN (11680days) the pool reaches after 250 years 5kg/m2 instead of 30kg/m2. Unfortunately, all other vegetation pools are affected also and their stocks are substantially reduced, too. 
-I decided for now to stick the ORCHIDEE-CAN parameter values. NV gave me an updated run.def file which contains substantial differences compared to the one he gave me earlier. I will test these parameters.
+=== heartwood ===
+I experience that the heartwood pool is still accumulating biomass after 500 yr of simulation reaching a stock of appr. 45kg/m2. This is very high compared to estimates of total biomass ranging between 3-15 kg/m2 (Houghton et al. 2005). Nonetheless, values larger than 20 kg/m2 are not uncommen (Keith et al., 2009).
+When using the value for tau_sap of the trunk version of ORCHIDEE (730days) instead of ORCHIDEE-CAN (11680days) the pool reaches after 250 years 5kg/m2 instead of 30kg/m2. Also all other vegetation pools are substantially reduced, too, and we end up having far too less carbon. An updated set of parameters from NV resulted in reasonable carbon stock, but we need more than 250 years to equilibrate the vegetation carbon stocks