New Zealand Journal of Ecology (1980) 3: 69- 84

Forest patterns and possum densities within podocarp/mixed hardwood forests on Mt. Bryan O'Lynn, Westland

Research Article
J. D. Coleman  
A. Gillman  
W. Q. Green  
  1. Protection Forestry Division, Forest Research Institute, P.O. Box 31-011, Christchurch, New Zealand

Eight major plant associations are identified, each with distinct physiographic requirements which results in a broad altitudinal stratification of the forest. The forests on low-altitude cutover terrace lands are dominated by Weinmannia racemosa and Cyathea smithii on partially cleared areas and by scrub broadleaved species on clearfelled sites; the unfelled mid-altitudinal slopes are dominated by W. racemosa and Quintinia acutifolia; the ridges by Metrosideros umbellata and W. racemosa; the high altitude forests by Griselinia littoralis and Libocedrus bidwillii ;and the alpine scrublands by scrub broadleaves, e.g. Olearia spp. and Dracophyllum spp. Forest mortality is also altitudinally stratified. Few dead stems occur in the low-altitude and alpine scrub forests, while in mid- and high-altitude forests 9.6-15.5% of all standing stems are dead. These forests are highly palatable to browsing animals, particularly possums (Trichosurus vulpecula), and appear to have bee!