Context: A 20 year old Nelder wheel planted with hoop pine (Araucaria cunninghamii Aiton ex D.Don) and Queensland maple (Flindersia brayleyana F.Muell.) in 18 spokes and 8 rings represents nominal point densities of 3580, 2150, 1140, 595, 305, 158, 82 and 42 stems/ha and offers an opportunity to examine competition and spatial interaction between these two species.Aims: To evaluate the intra-and inter-specific competition between two contrasting tree species, and determine the distance over which competition can be observed.Methods: Competition was estimated using Hegyi's index, implemented using the Simile visual modelling environment, and calibrated using non-linear least squares with PEST.