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