wiki:GroupActivities/CodeAvalaibilityPublication/ORCHIDEE-GMv3.2

Version 3 (modified by bguenet, 3 years ago) (diff)

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ORCHIDEE-GMv3.2

This version of ORCHIDEE has been used in a publication under review. << Reference to be added as soon as the manuscript is open for review >>.

Abstract

ORCHIDEE is a process-based ecosystem model developed for simulating carbon, water and energy fluxes in ecosystems, from site level to global scale1-3. ORCHIDEE-GM4 is a version specifically developed to integrate the management of grassland4. The equations describing management in ORCHIDEE are derived from PaSim5-8. Accounting for the management practices such as mowing, livestock grazing and fertilizer application on a daily basis, ORCHIDEE-GM proves capable of simulating the dynamics of leaf area index, biomass, and carbon fluxes of managed grasslands. ORCHIDEE-GM v1 was evaluated and some of its parameters calibrated at 11 European grassland sites representative of a range of management practices, with eddy-covariance net ecosystem exchange and biomass measurements. The model successfully simulates the net carbon budget of these managed grasslands4. Ref9 then added a parameterization of adaptive management through which farmers react to a climate-driven change of previous-year productivity. Though a full nitrogen cycle is not included in ORCHIDEE-GM, the positive effect of nitrogen fertilizers on grass photosynthesis rates, and thus on subsequent ecosystem productivity and carbon storage, is parameterized with an empirical function calibrated from literature estimates (v2.19). ORCHIDEE-GM v2.1 was applied over Europe to calculate the spatial pattern, inter-annual variability, and the trends of potential productivity, i.e. the productivity that maximizes simulated livestock densities assuming an optimal management system in each grid cell9. This version was further used to simulate the net carbon budget, budget trends, and the GHG balance of European grasslands during the last five decades at a spatial resolution of 25 km10. Ref11 recently updated the model to version 2.2 with the general parameterizations from ORCHIDEE Trunk.rev3623 (https://forge.ipsl.jussieu.fr/orchidee/browser/trunk#ORCHIDEE), and a new parameterization limiting grazing practices under specific conditions such as frost, snow cover and wet soil. ORCHIDEE-GM v2.2 was driven by projected future climate change to provide a European‐wide assessment of the future changes in productivity and phenology of grassland, and their consequences for the management intensity and the carbon balance.

At global scale, ORCHIDEE-GM v3.1 is a development of v2.1, includes a parameter adjustment for the C4 grassland biome and implemented a specific strategy for wild herbivores 12. Combining livestock production information, ORCHIDEE-GM v3.1 was applied to reconstruct a series of global gridded maps containing a time-dependent history of grassland management intensity. These maps are model-dependent, and provide a unique opportunity for models with explicit representation of grassland management to make a more accurate estimate of global carbon and GHG budgets of grassland 12 – as we have here. In this study, ORCHIDEE-GM v3.1 has been updated with the parameterizations of v2.2 to a new version named ORCHIDEE-GM v3.2.

Code access

Metadata

DOI TBD
Creator Jinfeng Chang
Affiliation LSCE, CNRS
Title TBD
Publisher Institut Pierre Simon Laplace (IPSL)
PublicationYear 2019
ResourceType Software
Rights This software is distributed under the CeCILL license
rightsURI http://www.cecill.info/
Subject Land surface model, pixel-to-point comparison, biomass
DataManager Karim Ramage (IPSL)
DataCurator Josefine Ghattas (IPSL)
ContactPerson Philippe Ciais (LSCE/CNRS)
FundingReference TBD