= ORCHIDEE-PEAT_V3 =

This version of ORCHIDEE has been used in the publication "Assessing CO2 Fluxes for European Peatlands in ORCHIDEE-PEAT with Multiple Peatland’s Plant Functional Types" by Liu et al. (2024). 

== Abstract ==
Peatlands are a large land carbon reservoir and are vulnerable to climate change and land use change like drainage for cultivation or forest plantation. We modified the ORCHIDEE-PEAT model by incorporating three additional peatland-specific plant functional types (PFTs), namely shrubs, mosses and trees in addition to peatland grasses to simulate peatland vegetation and soil CO2 fluxes. Model parameters controlling photosynthesis, autotropic respiration, and carbon decomposition have been optimized using eddy-covariance observations from 14 European peatland sites and a Bayesian optimization approach. This optimization has been conducted for each individual site (single-site calibration) and for all sites simultaneously (multi-site calibration). Calibration of the model on each individual site has been efficient in matching simulated gross primary production (GPP) and net ecosystem CO2 exchange (NEE) with observations, with notably better results for GPP. The optimized parameter values, related to plant traits and microbial decomposition processes, varied with environmental conditions (i.e., air temperature). For instance, Q10, the factor by which respiration rates increase for a 10 °C increase in temperature, significantly decreased as site temperature increased, aligning with independent field data. However, the default model did not accommodate spatial variations in parameters across different climatic contexts (i.e., trait-climate correlations), resulting in limited performance improvement from multi-site calibration. We thus incorporated two key trait-climate relationships inferred from single-site calibration into a new version of the ORCHIDEE-PEAT models. Using optimized model parameters across sites to account for their spatial variability holds significant promise for improving the accuracy of carbon cycle simulations in peatlands.

* See the version on the webinterface here: https://forge.ipsl.jussieu.fr/orchidee/browser/branches/publications/ORCHIDEE-PEAT_V3
* Extract it on a terminal as follows, typing anonymous as password: 
{{{
svn co --username anonymous svn://forge.ipsl.jussieu.fr/orchidee/branches/publications/ORCHIDEE-PEAT_V3 ORCHIDEE
}}}

== Metadata ==

|| DOI || [under request] ||
|| Creator || Liyang Liu ||
|| Affiliation || LSCE ||
|| Title || ORCHIDEE-PEAT_V3 ||
|| Publisher || Institut Pierre Simon Laplace (IPSL) ||
|| //PublicationYear// || 2024 ||
|| //ResourceType//  || Software ||
|| //Rights// || This software is distributed under the CeCILL license. ||
|| //rightsURI // || http://www.cecill.info/ ||
|| Subject || Multiple Peatland-specific PFTs ||
|| //DataManager// || Karim Ramage (IPSL) ||
|| //DataCurator// || Josefine Ghattas (IPSL) ||
|| //ContactPerson// || Liyang Liu (LSCE) ||
|| //FundingReference// || Liyang Liu was funded by Horizon Europe Grant Wet Horizons (GAP-101056848). ||