Phyllocladus aspleniifolius: Variability in the Population Structure, the Regeneration Niche and Dispersion Patterns in Tasmanian Forests

Abstract

This study aimed to determine the range of the regeneration niches of Phyllocladus aspleniifolius (Podocarpaceae) in terms of differential microsite occupation, population structure and dispersion pattern at 50 sites. The distribution and sizes of stems were mapped on belt transects to within 0.5 m, and the microsites of seedlings and saplings were recorded. A variety of population structures exist and are related to community floristics and structure. Community variation provides different microsite opportunities. Phyllocladus aspleniifolius showed a preference for elevated sites, including logs, buttresses and old stump mounds. Aggregation of regeneration is common and is determined by microsite distribution and seed dispersal characteristics. It is concluded that although the regeneration of P. aspleniifolius is favoured by catastrophic disturbance, smaller scale processes such as those evoked in the concept of non-equilibrium coexistence are likely to allow P. aspleniifolius to persist in all communities throughout its range in the absence of large scale disturbances.