Size-Structured Tree Populations in Gap-Dynamic Forest--The Forest Architecture Hypothesis for the Stable Coexistence of Species

The forest architecture hypothesis of tree species coexistence proposed here was developed from a general model of size-structured tree populations in gapdynamic rain forest. The model consists of a submodel describing the dynamics of the age distribution of local stands, which reflects gap-dynamic processes in a whole forest, and another describing the change in size distribution of trees in stands of each age. The model expresses the dynamics of both species-averaged systems and multi-species systems. In the model, the intensity of suppression of tree size growth, survival and seedling recruitment is a function of local crowding. Crowding is measured in each stand in terms of the cumulative basal area of trees of all species that are larger than the subject individual, while the potential rate of seedling recruitment is proportional to the basal area of mother trees in a whole forest (...)