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Phytosociological data from 51 forest study plots in the Maungataniwha Range, New Zealand, were analysed by numerical techniques including ordination, classification, and direct gradient analysis to identify vegetation/ environmental patterns. Nine community types segregated by specific ranges of environmental conditions were identified. Interpretations of ordination axes suggest temperature and moisture are prime factors affecting community composition.Gradient analysis is seen as an important step in evaluating the representativeness of existing and potential nature reserves. Previously, the techniques have been shown to be useful in an area where vegetation/environmental patterns are obvious. The present study demonstrates the utility where patterns are not obvious.

Gaps formed by stream laid gravels in a warm temperate Podocarp-Angiosperm rain forest in New Zealand were quickly invaded by 41 free-standing woody species. Height-age curves for the eight most frequent species were used to construct a 12 yr chronosequence which showed 18 species arrived by 0.9 yr and 33 by 1.9 yr. This rapid invasion was supplied from both gaps and mature forest and fitted the Initial Floristic Model coupled with a Facilitation Mechanism. Over the 12 yr period, stem density and births peaked at 0.9 yr and deaths at 1.9 yr with a natality of 39.5/m 2, a mortality of 38.5/m 2 and nearly 99~o dying as seedlings. Plant height increased to 5.1 m at 12.1 yr with height increment peaking at 43 cm/yr at 7.3 yr. Maximum potential heights ranged from 4 to 60 m and were positively correlated with longevity which varied from 20 to 1150 yr for 19 known species. A decline in height increment to 0.9 yr showed a below-ground component in intraspecific competition with significant negative correlations between stem density and height indicating a later above-ground component. There was no significant height competition amongst the 11 most frequent species and only one significant negative interspecific association. This suggests high species coexistence for which 'Equal chance' was probably the major mechanism. Given this coexistence, rapid species arrival, early sexual maturity and similar density and height-age patterns, the main dynamic variables may be maximum height, longevity and height increment, all of which are, partly, genetically programmed. Most dynamic affinities are with tropical forest, although height growth and species richness are warm temperate.

The root systems of all recognised New Zealand species of Corjaria and several of the hybrids were found to be nodulated. Ecological notes on the sites where plants were investigated and some comments on the significance of the genus in the New Zealand vegetation are included.