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In a study of the plant communities of two Australian rainforests, it was found that pioner species had high levels of nitrate reductase (EC 1.6.6.1) and were predominantly leaf nitrate assimilators. Under‐ and over‐storey species had low levels of shoot and root nitrate reductase activity, and many of them showed little capacity for nitrate reduction even when nitrate ions were freely available. Although closed‐forest species have lower levels of nitrate reductase than those of gaps and forest margins, their total nitrogen contents were similar, suggesting the former utilize nitrogen sources other than nitrate ions. Glutamine synthetase (EC 6.3.1.2) was present in the leaves of all species examined. In the leaves of pioneer species the chloroplastic isoform of glutamine synthetase predominted, while in most of the species typical of closed‐forest the cytosolic isoform accounted for at least 40% of total leaf activity. Low levels of chloroplastic glutamine synthetase were correlated with a low capacity for leaf nitrate reduction, and both are characteristic of many species that regenerate and grow for some time in shade. Low levels of chloroplastic glutamine synthetase imply that, in some of these woody plants, photorespiratory ammonia is re‐assimilated via cytosolic glutamine synthetase.

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Leaf litter production by lianes (=lianas) and trees was compared in an evergreen rain forest in subtropical Australia. Several successional stages were represented at the main site. Lianes contributed 2.2% of total basal area (69.6 m2 ha-1) of this site, but 24% of leaf litterfall (5.9–6.5 tha-1 y-2 over two years. Minor year-to-year variation in litterfall was attributed to incidence of severe storms, and drought. Lianes were responsible for about 17% of leaf litterfall in spring, 21% in the summerpeak, and 40% in autumn, more lianes than trees being deciduous. Leaf litter production by 23 individual species of liane, in relation to their basal area within the main site, was, on average, 15 times as great as that by 34 tree species, but declined more steeply between the species-groups of early and later succession. Tendrillar lianes, unlike twiners and scramblers, were confined to the ‘early’ successional group, and their foliage was spread across canopy surfaces, maximizing light interception. It was concluded that this contributed to greater production of leaf litter, per unit basal area, by tendrillar than by other climbers, and to the successional decline in leaf litterfall from lianes.