The data of Lloyd (1971) on the 'chosen tree' and 'chosen seedlings' in 5607 4 x 4 m plots in Russell forest are analysed using a simple transition matrix model. The most realistic analysis predicts little change in relative species composition, other than a slight increase in the softwoods. The virtue of the approach lies more in the questions it raises than in the predictions obtained. Before such models can be applied satisfactorily in New Zealand basic data on seedling survival, tree growth rates and average life spans are required for most indigenous species.
Agathis australis (A. australis, New Zealand kauri, Araucariaceae) exerts a substantial influence on soil properties and nutrient cycling, and mature specimens form an acidic organic soil layer beneath them that can be up to 2 m deep. We investigated whether phytotoxic compounds occurred in A. australis leaf litter and organic soil, and whether allelopathy may explain the distinctiveness of plant communities surrounding A. australis.