Northland

Descriptions of 247 forest stands at Waipoua Forest, Northland, were used to explore relationships between species richness (alpha-diversity) of the vascular flora and stand environmental characteristics, both in terms of total flora and within a number of the component synusiae. The Waipoua forests, with an average of 52 species per forest stand, are comparatively species-rich compared to other New Zealand forests.

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.