170 likes | 251 Views
Modeling the Greenhouse gases of cropland/grassland At European scale. N. Viovy, S. Gervois, N. Vuichard, N. de Noblet-Ducoudré, B. Seguin, N. Brisson, J.F. Soussana , P. Ciais. Aim of modeling: Simulate the GHG exchanges in response to
E N D
Modeling the Greenhouse gases of cropland/grassland At European scale N. Viovy, S. Gervois, N. Vuichard, N. de Noblet-Ducoudré, B. Seguin, N. Brisson, J.F. Soussana , P. Ciais
Aim of modeling: Simulate the GHG exchanges in response to • Environmental conditions (climate and management) based on • parameterization of biological processes of plant functioning • Advantage: • can be spatially explicit • can be used to extrapolate to the future • can be used to test several scenarios of climate evolution, • mitigation option etc….
State of art of modeling of greenhouse gases in ecosystems Large scale process models : (eg. LPJ, ORCHIDEE…) Can be run at european scale but crude description of processes Especially for agriculture (Mainly designed for natural vegetation, forest) Local process models (eg. Crops: STICS, grassland PASIM) Good description of processes and take into account for management But only at field level. Integrated model: (eg. Fasset) Integrate antropogenic dimention at fram level with simplified Ecosystems processes How to combine these approaches to assess european scale GHG budget On agricultural lands
Two possible approaches: Coupling Large scale models with local scale models Improve existing processes in large scale models for better Representation of crops and taking into account for management
Coupling ORCHIDEE with STICS and PASIM ORCHIDEE: Global scale model representing 12 « plant functionnal types » Simulate both biophysical and biogeochemical processes for net Exchange with the atmosphere Part of the IPSL climate model. STICS: Generic crop model designed for main crops type. Prediction of Crop yield. Take into account for fertilization, irrigation, PASIM: Designed to represent pasture. Include both cutting and grazing by Ruminants and there effects on the GHC balance (including N2O and CH4)
PASIM /STICS ORCHIDEE In situ forcing Coupling Comparison with in-situ data Climate forcing (ATEAM) Vegetation map (CORINE) « optimum management » European scale hybrid model European statistics e.g –fertilizers input,cutting/ grazing systems stocking rate, irrigation CO2,CH4,N2O budget on grasslands and crops Mitigation options Stategy of coupling
Data available at european Level Climate data:Climate data from ATEAM european project (EVK2-2000-00075) Combination of 10’x10’ climatology with 0.5°x0.5° CRU climate Data to construct a « pseudo 10’x10’ » data set for all the 20th century Land cover:CORINE land cover map Very high resolution and quality data set (but no information on crops types) Soil:European soil map (problem of access to the data) • The main problem is to obtain regional statistics on management Practices !
Cropland: Coupling STICS and ORCHIDEE e.g : LAI is calculated by STICS, photosynthesis by ORCHIDEE Improvement of the hybrid model:
‘validation’ site: Corn at Bondville (Illinois, US) ‘validation’ site: wheat at Ponca (Oklahoma, US)
January ORCHIDEE – STICS July ORCHIDEE - STICS January ORCHIDEE July ORCHIDEE January MODIS (Myneni et al.) July MODIS (Myneni et al.) Comparison of LAI between ORCHIDEE, ORCHIDEE – STICS and MODIS
GPP(gC/m2/day) ORCHIDEE ORCHIDEE-STICS Time evolution of simulated GPP and NEP (averaged over Europe) 9 4 NEP(gC/m2/day) Very stong increase in seasonal cycle -5
Simulation for the 20th century: impact of CO2, climate and management Atmospheric CO2 (ppm) 400 Atmospheric CO2 367.9 350 300 297 250 1920 1940 1960 1980 2000 1900 Mean annual temperature (°C) Annual rainfall (mm) Climate Species change Inorganic fertilizer + irrigation Management Organic fertilizer 1920 1940 1960 1980 2000 1900
Wheat yield (from FAO) 8 8.02 6 4 2 1.28 0 1900 1920 1940 1960 1980 CO2 CO2 + climate CO2 + climate + management Difference of production 2000-1900 CO2 + climate + management CO2 CO2 + climate Evolution of production (tC/ha/y) Wheat annual NPP 12 11.01 11 10.03 10 NPP ( tC / ha/y) 9 8 7.46 7 6 1920 1940 1960 1980
Grassland: coupling PASIM and ORCHIDEE Same forcing as for cropland (climatologic run) • Two scenarios: • cutting • grazing: automatic determination of stocking rate
Cutting scenario Yield (tC/(ha year)) NPP (tC/ha/y) N2O (Kg N/ha/y) Total GH effect (tC/ha/y)
Grazing scenario Stocking rate (LU/ha/y) NPP (tC/ha/y) N2O (Kg N/ha/y) CH4 (t/ha/y) Total GH effect (tC/ha/y)
Conclusions and perspectives The development of the hybrid