Simulation of the topological development of young eucalyptus using a stochastic model and sampling measurement strategy

International audience; Tree crown architecture affects light interception, biomass production and mechanical stability. Crown architecture is largely determined by the topological development of the plant due to meristem activity. Modeling approaches can provide new insights into the dynamics of plant topology, but they are often hampered by experimental difficulties in data collection on complex trees with numerous internodes, especially in tropical tree species that present the additional difficulty of continuous growth with no marked cessation. Tree topological structure shows high variability resulting from genotypic and environmental factors in real stands. In this paper, a stochastic model was developed to describe the topolog- ical development of trees. In the model, growth and branching processes are driven by the respective probabilities of activity, rest or death of apical and lateral buds. Because of its mathematical formulation, the model inversion can be done analytically - which is rare - and parameter values can be estimated from experimental data. A new strategy was defined to sample measurements and applied to five eucalyptus trees. Incomplete systems were also defined for the case, common with trees, of incomplete data- sets. After parameter estimation, simulation of random eucalyptus tree was presented. The model could describe tree topological development of eucalyptus reasonably well. This work offers a simple and practical method to describe the topological development of trees with continuous growth. It can realistically and flexibly describe the canopy topological development, and has the potential to be integrated with the process of biomass production and allocation for functional-structural plant modeling in the future.