The ecology of Araucaria species in New Guinea. II. Pattern in the distribution of young and mature individuals and light requirements of seedlings.

Conventional pattern analysis and segregation analysis were used to investigate the hypothesis that young and mature individuals of Araucaria hunsteinii were not usually found growing in close association whilst the distribution of young and mature individuals of A. cunninghamii was essentially random. It was considered that this pattern reflected a difference in regeneration strategy between the two species, A. hunsteinii being a gap regenerator and A. cunninghamii a shade-tolerant species. A seedling growth-experiment using three different shade treatments and four temperature treatments tested this hypothesis further. Results show that A. hunsteinii is more dependent on high light intensity than A. cunninghamii for the production of biomass. A. cunninghamii produces more biomass than A. hunsteinii under all treatment conditions.