Mount Colenso

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.

Plotless methods were used to sample four forest stands situated at different altitudes on Mount Colenso, Ruahine mountain range, North Island, New Zealand. The altitudinal distributions of the main woody species are described graphically. All species have overlapping altitudinal ranges, so that no clear altitudinal 'belts' can be distinguished. The forest composition is regarded as a continuum showing gradual variation from diverse mixed (podocarp-beach) forest on the terraces of the Kawhatau river (c. 2000 ft.