A functional-structural plant growth model has been developed to explore how biophysical principles, meristem activity, carbon economy and selection influence the ontogenetic patterns in three-dimensional (3D) growth of trees.
The dynamics in the 3D plant structure depend on the production of metamers (leaves, internodes, and appending buds) and leaf and wood loss and sapwood to heartwood transition. From this model structure we can predict the overall (emergent) growth patterns: life cycle changes in 3D structure, including the stem and crown size, leaf distribution, scaling between leaves and wood, and reproductive output of trees in different forest light environments. Based on other studies, we are currently extending the plant growth model with water relations, carbon and nitrogen economy, hormone control systems, and mechanical safety margins and selection “aiming” at maximizing reproductive output for 3D-growth patterns of trees along climatic gradients, as well as in the heterogeneous light conditions of forests. We have tested some model predictions against data from tropical tree communities, and are currently working on test against tree species along climatic gradients in Europe and the tropics.