<I>Nothofagus fusca</I>

A population of red beech (Nothofagus fusca) seedlings was studied in a forest dominated by red beech but apparently with little regeneration. Estimates of the germination, growth and survival rates of seedlings growing on different microsites were obtained in three, one hectare stands over a one year period and the size and age structure of the population examined. Irregular and sometimes massive seedfalls occur but some seedlings establish at least every two or three years.

The population structure of red beech (Nothofagus fusca) is described for four forest stands situated at different altitudes on Mount Colenso. Data on red beech seedling densities and frequency distributions of living and dead tree diameters (d.b.h.) are presented. Red beech seedlings are shown to be more numerous, and on average larger, on decaying red beech logs than elsewhere. This seedling site preference could lead to, a 'regeneration cycle', and explain the 'regeneration gaps' and bimodal d.b.h. frequency distributions commonly found in red beech forest in the Ruahine ranges.

Population size and structure of 52 isolated Nothofagus fusca stands were investigated in the lower Otira Valley, 3-6 km from a major population centre in the upper Taramakau catchment. The approximate age of N. fusca pioneer trees, estimated from partial increment cores and calculations based on diameter growth rates, indicated that nearly all isolated stands originated after 1600 AD, predominantly during the periods 1600-1760 AD and 1865-1910 AD.