1. General Model Information

Name: CARbon DYNamics

Acronym: CARDYN

Main medium: terrestrial
Main subject: forestry,biogeochemistry
Organization level: forest
Type of model: not specified
Main application:
Keywords: remote sensing, fPAR, LAI,carbon balance


Frank Veroustraete
Flemish Institute of Technological Research (VITO)
Centre for Remote Sensing and Atmospheric Processes (CETAP)
Boeretang 200, B-2400
Tel.: +32-14-335866
Fax: +32-14-321185
Email: veroustf@vito.be



The purpose of CARDYN is to predict the carbon fluxes through the soil-vegetation and vegetation-atmosphere interfaces mainly for climate change research. It was originally developed for deciduous forest stands. Four compartments are defined in the model, between which all carbon fluxes are evaluated: a green compartment of organs with large mass fluctuations like leaves and fine roots, a non-green phytomass compartment (stem, branches, woody roots), a litter compartment, and the atmosphere as an infinite source and sink of carbon. CARDYN calculates the carbon dynamics of a forest stand on an hourly basis using a simple big-leaf model of the canopy. The dynamics of carbon are driven with remotely sensed values of fAPAR (fraction of absorbed photosynthetically active radiation). Also, photosynthesis is dependent on air temperature and CO2 content of the atmosphere. It is calculated using a Farquhar type of model, the CO2 fertilization effect being modelled directly. Allocation to green and non-green phytomass follows a (constant proportion) changing proportion approach according to phase-space control principles. The changing proportion is not controlled by nutrient or water supply, but by fAPAR temporal evolution determined from remote sensing. Litter fall is also assumed to be a constant fraction of the green and non-green phytomass. Litter carbon is decomposed dependent on temperature. The model calculates mainly the net primary productivity (NPP) and the net ecosystem exchange (NEE) of carbon.

II. Technical Information

II.1 Executables:

Operating System(s): DOS Download: CARDYN.EXE

II.2 Source-code:

Programming Language(s): FORTRAN CARDYN.FOR, source code for deciduous forestand poplar plantation.

II.3 Manuals:

Not yet available, but the source code is extensively documented concerningthe basic principles of the model, programming aspects and parameters used.

II.4 Data:

Climatological file (KLIMATO.KLI), neededto run the executable. Output files are simple ASCII, and should be processedfurther in a worksheet for grtaphical presentation of results.CO2 concentrationsare calculated according to the year of simulation according to two scenario’s(see publication in Ecological Modelliung).

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Veroustraete, F. 1994.On the use of a simple deciduous forest model for the interpretationof climate change effects at the level of carbon dynamics,
Ecological Modelling 75/76 : 221-237.

Veroustraete, F. , J. Patyn and R.B. Myneni, 1994. Forcing of a simple ecosystem model with FAPAR and climatic data to estimateregional scale photosynthetic assimilation.
In : ”Vegetation, Modellin and Climatic Change Effects. pp 151-177. (Edited by F. Veroustraete, R. Ceulemans et al.), SPB Ac. Publishing bv. The Hague.

Veroustraete, F. , J. Patyn and R.B. Myneni, 1996. Estimating Net Ecosystem Exchange of Carbon Using the Normalized DifferenceVegetation Index and an Ecosystem Model,
Remote Sens. Environ. 58 : 115-130

V. Further information in the World-Wide-Web

HomePage of CETAPand of the EU project Euroflux(University of Antwerp) .

VI. Additional remarks

The model has been applied initially to evaluate the carbon balanceof a decdiuous forest in the Ardennes region in Belgium. In the LTEEF projectthe model was validated with CO2 fluxes measured with an eddy covariancesetup at the Bray site Pinus pinaster plantation. Actually the model isapplied for a site in Brasschaat, Belgium for extensive validation in amulti-species, multi-layered forest, with eddy covariance data (Eurofluxnetwork), using NOAA-AVHRR data for 1996 and 1997.

CARDYN was recently successfully applicated in the EU-project LTEEF("Long Term Effects of CO2 increase and climate change on EuropeanForests",project-leader G.M.J. Mohren). It is also applied withinthe ongoing European project ECOCRAFT (climate change impacts on Europeanforests , project leader: P.G. Jarvis).

Last review of this document by: FrankVeroustraete and M. Sonntag:April 16th, 1997.
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:40 CEST 2002

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