doc7. Taking into account climate effects on forest dynamics
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7. Taking into account climate effects on forest dynamics
Modelling climate effects on forest dynamics: Dynaclim project Hendrik Davi Plan 3. Introduction 5. Modelling forest carbon and water cycles: Average tree approach 7. Taking into account climate effects on forest dynamics: coupling functional and dynamics models 9. Dynaclim schem Introduction Variations depuis 1000 (GIEC, 2007) Introduction CO2 increase Climatic changes Forest dynamics Management N,P deposition Land use changes Vegetation functionning Forest carbon sink Modelling climate effects on forest dynamics: Dynaclim project Hendrik Davi Plan 3. Introduction 5. Modelling forest carbon and water cycles: Average tree approach 7. Taking into account climate effects on forest dynamics: coupling functional and dynamics models 9. Dynaclim schema Estimating carbon fluxes Leaves respiration Canopy photosynthesis Wood respiration Roots respiration Heterotrophic respiration Estimating water fluxes rain Water interception by leaves Transpiration Drainage Soil evaporation CASTANEA (Dufrêne et al., 2005) Average tree model Canopy= n layers Reserve compartment unlocated Soil= 2 layers Trunc and branches Fine and coarses roots CASTANEA (Dufrêne et al., 2005) Leaf carbon budget H20 budget Canopy Na=f(Nm)*LMA Ryan Rf= f(Na,T) Farquhar A=f(Na,T,PAR) PAR (Verhoef) LAI ETR Penman Monteith LMA EPsol (Penman) SOC (Parton) NPP Ball & al Gs= f(A,HR) Gc CH2OΕ ecosystem Soil Water Model Sala & al Multilayer model Key ecosystem parameters Leaves traits • Leaf Area Index (LAI) • Leaf nitrogen content (N) • Leaf Mass per Area (LMA) Aboveground biomass (Bwood) Roots biomass (Broots) Soil Water Reserve (SWR) Soil Organic Carbon (SOC) Branch bag Dendrometer Gas exchange sapflow Biochemical photosynthesis photos LAI2000 Hesse: beech Le Bray: maritime pine Puéchabon: Holm oak Loobos: Scots pine NEE gC m d 2 1 6 Hesse 2001 4 2 0 2 4 6 8 beech 10 12 1janv 11mar 20may 29juil 7oct measurements simulations NEE g C m2d 1 Model evaluation on Net Ecosystem Exchange (Davi et al. 2006a) 3 3 Puéchabon 2001 7oct 16déc Loobos 1997 2 1 0 1 2 3 16déc measurements 1 4 7oct simulations NEE g C m2 d1 C m d NEEC g 2 1 2 16dec 3 le Bray 2001 2 1 0 1 2 3 4 5 Maritime pine 6 1janv 11mars 20mai 29juil 0 1 2 3 4 Holm oak 5 1janv 11mars 20mai simulations measurements) 5 29juil 7oct 16déc Scots pine 6 1janv 11mars 20mai measurments simulations 29juil 5 1 Branch bag 4 3 2 1 0 9avr 29mai Asssimilation mesurée 18juil 6sept REW 4 3 2 y = 1,03x + 0,01 2 R = 0,95 1 26oct 0 0 Assimilation simulée azote foliaire diminuant au cours de la saison Transpiration du couvert 5 6 simulée mm jour Photosynthèse journalière µmol CO2 m 2 Model evaluation on several processes (Davi et al. 2005) 1 2 3 4 1 mesurée par flux sève mm jour Eau du sol à Hesse 19972001 1,4 1,2 1 0,8 0,6 0,4 0,2 0 0 150 300 450 600 750 simulé 5 900 1050 mesuré 1200 1350 1500 1650 1800 Effect of global change (Davi et al., 2006a) Contribution to trend gC m 2 y1 6 3 0 3 6 Bray SO Pinus p. Puéchabon Hesse Fontainebleau Fontainebleau Fontainebleau SE Quercus i. NE Fagus s. N Quercus p. N Fagus s. N Pinus s. CO2 effect Water stress effect Other climatic effects Interaction effects Phenology effect Summary of the role played by each factor of global changes in simulated trends on NEE between 1960 and 2100. Modelling climate effects on forest dynamics: Dynaclim project Hendrik Davi Plan 3. Introduction 5. Modelling forest carbon and water cycles: Average tree approach 7. Taking into account climate effects on forest dynamics: coupling functional and dynamics models 9. Dynaclim schema The forest dynamics: one example Montage photo : ONF The forest dynamics: one example Ventoug model Beech regeneration under pine canopy 1 dynamique, 2 (ou 3) variantes : Pin + Hêtre 1 versant sud Hêtre pur 1 bis versant sud Pin P. nigra P. sylvestris P. uncinata 2 Sapin + Hêtre + Pin versant Nord P. Dreyfus South of MontVentoux : Example of simulated dynamics Pine 1 P. nigra, P. sylvestris P. uncinata Pine + beech P. Dreyfus The processes: How integrate climate? Growth : dH, dD = POT x RED1 x RED2 (species, age, fertility) (density, canopy structure, species) (competition, species ) Mortality : Probability = f (species, RED1, RED2 ) Regenération : f (age of sources and distance sinksource) Integrate climate effect and explicit fertility effect • which structure ? • how much ecophysiology ? Dynamics Functioning Models type tree Cohorts tree Spatially explicit Cohorts Average tree Spatially explicit + + Description of processes Reproduction Dispersion Vertical fluxes Efficient dispersion Energy budget Cycle C Germination Growth Growth of saplings Mortality Mortality due to perturbations leaves Trunk Cycle H2O Roots Lateral fluxes Soil Modelling climate effects on forest dynamics: Dynaclim project Hendrik Davi Plan 3. Introduction 5. Modelling forest carbon and water cycles: Average tree approach 7. Taking into account climate effects on forest dynamics: coupling functional and dynamics models 9. Dynaclim schema One example :Hybrid approach Dyanclim model Structure integration Climate and fertility Resolution of functional models (ex 1 ha) Model « Average Tree » Available carbon for growth Fine resolution of dynamics models (ex 100 m²) Model tree semispatially explicit Equations of Growth Survival Regeneration The spatial levels T Tree Interaction between trees cells de 10 x 10 m² TLC Interaction between cells Group of cells Forest Functionning FLC expansion : Sample of group «Analyse unit »: management : UA interactions Seeds fluxes Forest H. Davi CASTANEA Lib F region Dynaclim P. Dreyfus VentouxG Dynaclim in CAPSIS scenario Gidcard Methodprovider step Gsettings Gmodel GStand Gtree FmSpecies * FmSettings Dcsettings GTCStand GMaddtree DcModel DcMethodprovider Gplot Polygonalplot DcStand DcInventory DcSpecies * FmClimate FmClimateReader FmClimateDay FmSpeciesReader DcAU DcFLCell DcTree FmSoilLayer * FmCanopy FmWood FmSoilLayer * Polygonalcell DcPlot FmSoil DcTLCell Squarecell Some conclusions Four challenges: 3. Effect of climate on unknown processes: Ventoux as “site atelier” • Allocation • Reproduction • Growth of saplings • Mortality=> existing of drought threshold and link with other biological effects (insects) 4. How link dynamics and functioning: what accuracy for what aim? 5. Management effect and interaction with climate 6. How infer some generalization to improve ecological theories? Use process base model to test theory of community ecology and evolution => Couple genetics model and dynamics models (fitness, plasticity) and use as theoretical tools