Ecology of hard beech (Nothofagus truncata) in southern outlier stands in the Haast Ecological District, South Westland, New Zealand
- Botany Department, University of Otago, P.O. Box 56, Dunedin, New Zealand
- Botany Division D.S.I.R.,Private Bag, Dunedin, New Zealand
Vegetation and habitat descriptions are given for sites that span the very limited environmental range of southern outlier stands of hard beech (Nothofagus truncata). These are on well-drained, north to northwest aspect slopes at 44 oS in South Westland, 260km south of the species' previously assumed southern limit. Size class distributions and diameter growth rates of hard beech stems indicate that it is competing effectively with podocarp and broadleaved species, including the two other beeches present. Of the three local species (mountain beech—N. solandri var. cliffortioides and silver beech—N. menziesii), only hard beech showed a significant relationship between stem diameter and age, though diameter growth rates were generally similar among the three species.
The erratic distribution of the three local beech species in the Haast and adjacent Paringa Ecological Districts is discussed in relation to possible glacial refugia.
The scientific and conservation values of the outlier stands are emphasised.