temperate rain-forest

Habitat use of a forest bird community was studied in temperate rainforests in South Westland, New Zealand between 1983 and 1985. This paper examines foraging methods, feeding stations and seasonal variations in the availability and use of food types and provides a brief review of the subject. The forest bird community was comprised of a large number of apparently generalist feeders and few dietary specialists. However, the degree of foraging specialisation should not be viewed only in relation to the food types consumed.

Functional convergence of different communities in similar environments would be expected as an outcome of the operation of 'assembly rules'. At an ecological level, competitive exclusion would restrict the co-occurrence of species with similar niches. Repetition of competitive sorting on an evolutionary time scale might lead to character displacement.

Light environments in two lowland New Zealand podocarp rainforests are described using data from quantum sensors. Mean daily total photosynthetic photon flux density (PPFD) in the forest understorey varies from 2.6-5.2% incident PPFD in summer and 1.0-2.5% in autumn, and in gaps from 5.0-16.6% in summer and 6.3-8.3% in autumn. Pronounced differences in understorey PPFD occur between clear and overcast days. Overcast days tend to have a lower proportion of 2-minute periods with very low mean PPFD than clear days.