LAMASUS - Response functions for effects of peatland drainage on peatland CO2 and CH4 budgets across Europe

We provide here functions describing the responses of peatland CO2 and CH4 budgets to drainage across Europe, based on the findings of Nguyen et al. (2025) and based on simulation results with the land surface model ORCHIDEE-PEAT provided by Liu et al. (2025). This work is part of the knowledgbase of response functions describing climate impacts of land use management, which represents deliverable D5.1 of the EU project LAMASUS. The file “ORCHIDEE_Peat_NEE&CH4_sensitivities.nc” contains parameters that give the average peatland net-emissions of CO2 (i.e., net ecosystem exchange – NEE) and CH4, both for undrained and drained conditions. For drained conditions, we assume a water table depth of 50 cm. Note that we also report the sensitivity of NEE and CH4 emissions to changes in water table depth, as well as the natural water table depth under undrained conditions. Based on this information, one can estimate NEE and CH4 for any reasonable value of water table depth between 0 cm and 50 cm, as described in the equation below for the example of NEE. Here, NEEd is the NEE at the new water table depth WTPd. NEEinit is the NEE at undrained conditions with an initial water table depth WTPinit. NEEsens gives the change in NEE per change in water table depth. The water table depth depended change in CH4 emissions can be calculated accordingly. The table below gives an overview of the variables contained in the net-cdf file. Table: List of parameters describing changes in peatland emission of CO2 (net ecosystem exchange, NEE) and CH4 due to changes table depth. Parameter Explanation Units NEE_init NEE when undrained gC m-2day-1 NEE_drainage NEE when drained gC m-2day-1 NEE_sen NEE sensitivity to WTD changes gC m-2day-1cm-1 CH4_init CH4 when undrained gCH4 m-2day-1 CH4_drainage CH4 when drained gCH4 m-2day-1 CH4_sen CH4 sensitivity to WTD changes gCH4 m-2day-1cm-1 WTD Water table depth when undrained cm References Liu, L., Qiu, C., Xi, Y., Salmon, E., Kalhori, A., Artz, R. R. E., and others: Assessing CO₂ fluxes for European peatlands in ORCHIDEE-PEAT with multiple plant functional types, J. Adv. Model. Earth Syst., 17, e2025MS004940, https://doi.org/10.1029/2025MS004940, 2025. Nguyen, T. H., Ciais, P., Liu, L., Xi, Y., Qiu, C., Salmon, E., Kalhori, A., Guimbaud, C., Peichl, M., Ratcliffe, J. L., Noumonvi, K. D., and Li, X.: Modeling the impact of drainage on peatland CO₂ and CH₄ fluxes and its underlying drivers, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-352, 2025.