Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions

Simulation models are extensively used to predict agricultural productivity and greenhouse gas emissions. However, the uncertainties of (reduced) model ensemble simulations have not been assessed systematically for variables affecting food security and climate change mitigation, within multi‐species...

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Autores principales: Ehrhardt, F., Soussana, J.F., Bellocchi, G., Grace, P., McAuliffe, R., Recous, S., Sándor, R., Smith, P., Snow, V., Merbold, Lutz
Formato: Journal Article
Lenguaje:Inglés
Publicado: Wiley 2018
Materias:
Acceso en línea:https://hdl.handle.net/10568/92474
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author Ehrhardt, F.
Soussana, J.F.
Bellocchi, G.
Grace, P.
McAuliffe, R.
Recous, S.
Sándor, R.
Smith, P.
Snow, V.
Merbold, Lutz
author_browse Bellocchi, G.
Ehrhardt, F.
Grace, P.
McAuliffe, R.
Merbold, Lutz
Recous, S.
Smith, P.
Snow, V.
Soussana, J.F.
Sándor, R.
author_facet Ehrhardt, F.
Soussana, J.F.
Bellocchi, G.
Grace, P.
McAuliffe, R.
Recous, S.
Sándor, R.
Smith, P.
Snow, V.
Merbold, Lutz
author_sort Ehrhardt, F.
collection Repository of Agricultural Research Outputs (CGSpace)
description Simulation models are extensively used to predict agricultural productivity and greenhouse gas emissions. However, the uncertainties of (reduced) model ensemble simulations have not been assessed systematically for variables affecting food security and climate change mitigation, within multi‐species agricultural contexts. We report an international model comparison and benchmarking exercise, showing the potential of multi‐model ensembles to predict productivity and nitrous oxide (N2O) emissions for wheat, maize, rice and temperate grasslands. Using a multi‐stage modelling protocol, from blind simulations (stage 1) to partial (stages 2–4) and full calibration (stage 5), 24 process‐based biogeochemical models were assessed individually or as an ensemble against long‐term experimental data from four temperate grassland and five arable crop rotation sites spanning four continents. Comparisons were performed by reference to the experimental uncertainties of observed yields and N2O emissions. Results showed that across sites and crop/grassland types, 23%–40% of the uncalibrated individual models were within two standard deviations (SD) of observed yields, while 42 (rice) to 96% (grasslands) of the models were within 1 SD of observed N2O emissions. At stage 1, ensembles formed by the three lowest prediction model errors predicted both yields and N2O emissions within experimental uncertainties for 44% and 33% of the crop and grassland growth cycles, respectively. Partial model calibration (stages 2–4) markedly reduced prediction errors of the full model ensemble E‐median for crop grain yields (from 36% at stage 1 down to 4% on average) and grassland productivity (from 44% to 27%) and to a lesser and more variable extent for N2O emissions. Yield‐scaled N2O emissions (N2O emissions divided by crop yields) were ranked accurately by three‐model ensembles across crop species and field sites. The potential of using process‐based model ensembles to predict jointly productivity and N2O emissions at field scale is discussed.
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spelling CGSpace924742025-12-08T09:54:28Z Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions Ehrhardt, F. Soussana, J.F. Bellocchi, G. Grace, P. McAuliffe, R. Recous, S. Sándor, R. Smith, P. Snow, V. Merbold, Lutz animal feeding crops mixed farming Simulation models are extensively used to predict agricultural productivity and greenhouse gas emissions. However, the uncertainties of (reduced) model ensemble simulations have not been assessed systematically for variables affecting food security and climate change mitigation, within multi‐species agricultural contexts. We report an international model comparison and benchmarking exercise, showing the potential of multi‐model ensembles to predict productivity and nitrous oxide (N2O) emissions for wheat, maize, rice and temperate grasslands. Using a multi‐stage modelling protocol, from blind simulations (stage 1) to partial (stages 2–4) and full calibration (stage 5), 24 process‐based biogeochemical models were assessed individually or as an ensemble against long‐term experimental data from four temperate grassland and five arable crop rotation sites spanning four continents. Comparisons were performed by reference to the experimental uncertainties of observed yields and N2O emissions. Results showed that across sites and crop/grassland types, 23%–40% of the uncalibrated individual models were within two standard deviations (SD) of observed yields, while 42 (rice) to 96% (grasslands) of the models were within 1 SD of observed N2O emissions. At stage 1, ensembles formed by the three lowest prediction model errors predicted both yields and N2O emissions within experimental uncertainties for 44% and 33% of the crop and grassland growth cycles, respectively. Partial model calibration (stages 2–4) markedly reduced prediction errors of the full model ensemble E‐median for crop grain yields (from 36% at stage 1 down to 4% on average) and grassland productivity (from 44% to 27%) and to a lesser and more variable extent for N2O emissions. Yield‐scaled N2O emissions (N2O emissions divided by crop yields) were ranked accurately by three‐model ensembles across crop species and field sites. The potential of using process‐based model ensembles to predict jointly productivity and N2O emissions at field scale is discussed. 2018-02 2018-05-02T18:48:15Z 2018-05-02T18:48:15Z Journal Article https://hdl.handle.net/10568/92474 en Open Access Wiley Ehrhardt, F., Soussana, J.-F., Bellocchi, G., Grace, P., McAuliffe, R., Recous, S., Sándor, R., Smith, P., Snow, V. et al. 2018. Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions. Global Change Biology 24(2):e603–e616
spellingShingle animal feeding
crops
mixed farming
Ehrhardt, F.
Soussana, J.F.
Bellocchi, G.
Grace, P.
McAuliffe, R.
Recous, S.
Sándor, R.
Smith, P.
Snow, V.
Merbold, Lutz
Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title_full Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title_fullStr Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title_full_unstemmed Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title_short Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions
title_sort assessing uncertainties in crop and pasture ensemble model simulations of productivity and n2o emissions
topic animal feeding
crops
mixed farming
url https://hdl.handle.net/10568/92474
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