Development and Extrapolation of a General Light Use Efficiency Model for the Gross Primary Production

The global carbon cycle is one of the large biogeochemical cycles
spanning all living and non-living compartments of the Earth
system. Against the background of accelerating global change, the
scientific community is highly interested in analyzing and
understanding the dynamics of the global carbon cycle and its
complex feedback mechanism with the terrestrial biosphere. The
international network FLUXNET was established to serve this aim
with measurement towers around the globe. The overarching objective
of this thesis is to exploit the powerful combination of carbon
flux measurements and satellite remote sensing in order to develop
a simple but robust model for the gross primary production (GPP) of
vegetation stands. Measurement data from FLUXNET sites as well as
remote sensing data from the NASA sensor MODIS are exploited in a
data-based model development approach. The well-established concept
of light use efficiency is chosen as modeling framework. As a
result, a novel gross primary production model is established to
quantify the carbon uptake of forests and grasslands across a broad
range of climate zones. Furthermore, an extrapolation scheme is
derived, with which the model parameters calibrated at FLUXNET
sites can be regionalized to pave the way for spatially continuous
model applications.