Biosphere ModelingBiosphere ModelingGalina ChurkinaGalina Churkina

MPI for BiogeochemistryMPI for Biogeochemistry

Biosphere -Biosphere -

Biosphere modeling?Biosphere modeling?

… all living and non-living matters which have been affected in any way by life…

Vegetation, ecosystems

Human impacts

Types and purposes of vegetation modelsTypes and purposes of vegetation models Models’ verificationModels’ verification Advantages and issuesAdvantages and issues

Vegetation ModelingVegetation Modeling

PurposesPurposesTo examine and predict:To examine and predict:

plant population dynamics considering plant population dynamics considering competition between individual species competition between individual species

changes in energy flows and changes in energy flows and biogeochemical cycling of ecosystemsbiogeochemical cycling of ecosystems

vegetation distribution and its shifts vegetation distribution and its shifts (biogeography models)(biogeography models)

Plant population models Plant population models ((gap modelsgap models))

To predict plant population dynamics To predict plant population dynamics considering:considering: plant competitionplant competition establishmentestablishment growthgrowth mortalitymortality

Time step - yearsTime step - years

To describe vertical exchange of energy To describe vertical exchange of energy and water fluxesand water fluxes

Vegetation is a “barrier” between land Vegetation is a “barrier” between land surface and the atmospheresurface and the atmosphere

Carbon flux was addedCarbon flux was added Time step - secondsTime step - seconds

Soil-Vegetation-Atmosphere-Soil-Vegetation-Atmosphere-TransferTransfer

Ecosystem modelsEcosystem models

Changes in carbon, nitrogen, water Changes in carbon, nitrogen, water fluxes and/or storage of ecosystemsfluxes and/or storage of ecosystems

Trees are not defined individuallyTrees are not defined individually

Climatic inputs + plant Climatic inputs + plant physiology/empiric relationshipsphysiology/empiric relationships

Time step - days, months, yearsTime step - days, months, years

DDynamicynamic G Globallobal V Vegetationegetation M Modelsodels

To examine and predict changes in To examine and predict changes in vegetation distributionvegetation distribution

Changes in carbon, water fluxes and/or Changes in carbon, water fluxes and/or storage of ecosystemsstorage of ecosystems

Time step - months, yearsTime step - months, years

Inputs and outputsInputs and outputs

Selected inputs Selected outputs Vegetation

distribution Satellite FPAR

Other satellite data c

Biogeoche- mical fluxes Leaf Area Index

Vegetation Distribution

Satellite based models CASA X X X

GLO-PEM X X X SDBM X X TURC X X X SIB2 X X X X

Models for seasonal biogeochemical fluxes HRBM X

CENTURY X X TEM X X

CARAIB X X X FBM X X X

SILVAN X X X

BIOME-BGC X

X X

KGBM X X X X

Models for seasonal biogeochemical fluxes and vegetation structure LPJ X X X DOLY X X X

HYBRID X X X

after Cramer et al. 1999

How to verify the model results?How to verify the model results?

Site Level ConstraintsSite Level Constraintsg

C/m

2/d

ay

gC

/m2/d

ay

month month

Measured data are from Tharand, Germany

After parameter optimization

Spatial constrainsSpatial constrains

month

Remotely sensed DATA from MODISLAI simulated with BIOME-BGC model

Global constraints?Global constraints?

Effect of industrial N deposition on global normalized NEP and NPP (kgC/m2/yr)

Verification at different scalesVerification at different scalesGlobal:• atmospheric inversions

Regional:• country statistics (forest inventories,etc.)• remote sensing • Landsat, MODIS, SeaWiFS

Site level: measurements of • ecosystem/soil C fluxes,• C/N content in vegetation or soil• mean residence time of C in soil• etc.

Vegetation model

AdvantagesAdvantages

Simulate responses of ecosystems to Simulate responses of ecosystems to regionally heterogeneousregionally heterogeneous temperature and rainfall anomaliestemperature and rainfall anomalies nitrogen deposition ratenitrogen deposition rate land useland use

Generate predictionsGenerate predictions

Issue Issue

Verification of model results at regional Verification of model results at regional and global scalesand global scales

Simulation of human impacts on Simulation of human impacts on ecosystemsecosystems

Churkina & Running, 1998

Dominant controls for carbon, Dominant controls for carbon, energy and water fluxesenergy and water fluxes

Radiation

Water Temperature

Can we neglect human activities?Can we neglect human activities?