  Poplar is one of the best fast-growing trees in the world, widely used for
windbreak and wood product. Although architecture of poplar has direct impact
on its applications, it has not been descried in previous poplar models,
probably because of the difficulties raised by measurement, data processing and
parameterization. In this paper, the functional-structural model GreenLab is
calibrated by using poplar data of 3, 4, 5, 6 years old. The data was acquired
by simplifying measurement. The architecture was also simplified by classifying
the branches into several types (physiological age) using clustering analysis,
which decrease the number of parameters. By multi-fitting the sampled data of
each tree, the model parameters were identified and the plant architectures at
different tree ages were simulated.
