Changes between Version 5 and Version 6 of GroupActivities/CodeAvalaibilityPublication/ORCHIDEE-CN-P_v1.2_r5986

Timestamp:

2020-03-20T05:12:44+01:00 (4 years ago)

Author:

dgoll

Comment:

--

GroupActivities/CodeAvalaibilityPublication/ORCHIDEE-CN-P_v1.2_r5986

@@ -4 +4 @@
 to be submitted to GMD. Reference will be added later.
 
-== Model information ==
-Global version of the nutrient enabled version of ORCHIDEE-CNP. 
+== Abstract ==
+Nitrogen (N) and phosphorus (P) constraints on carbon (C) and energy exchanges between
+terrestrial biosphere and atmosphere are a major source of uncertainty regarding the drivers
+of the land C sink. In this study, we evaluated the performance of the global version of the
+land surface model ORCHIDEE-CNP (v1.2) which explicitly simulates N and P cycles on
+land, based on a compilation of data from remote-sensing, ground-based measurement
+networks and ecological databases. The sensitivity of gross primary productivity (GPP) to
+increasing CO 2 and water availability in ORCHIDEE-CNP is more realistic in the nutrient-
+enabled model version. However, this model version cannot capture the current land C sink
+in the North Hemisphere (NH), suggesting that either (1) other processes (besides CO 2
+fertilization) currently not well resolved in global models such as biomass turnover, land
+management, and soil decomposition might play an important role, or (2) that ORCHIDEE-CNP underestimates the ability of ecosystems to circumpass nutrient constraints on biomass
+built up under elevated atmospheric CO 2 concentrations . Components of the N and P budgets
+at biome level are in good agreement with independent estimates, but large-scale patterns in
+ecosystem stoichiometry cannot be reproduced. The analysis of plant use efficiencies of light,
+water, C, N and P and seasonal dynamics reveal issues with respect to canopy processes,
+plant respiration and growth allocation in ORCHIDEE-CNP. We propose ways how to
+address the model biases by refining the canopy light absorption processes, root and leaf
+phenology processes and dynamics of biomass turnover and by better representing soil
+processes related to decomposition, stabilization of soil organic matter and inorganic P
+transformation.
 
 == Code access ==